MXPA97001352A - Base board system adjusted to pres - Google Patents

Abstract

The present invention relates to an electrical charge center having a housing with a push screw fastening accessory, a door latch comprising a one piece molded member, having a flexible tongue which the door latch towards the edge of the hinged door keeping a hook engaged in a deflected manner with an edge of the underside of the cutout, a barraneutra having an elongated body portion with a trapezoidal cross-sectional area with the side walls extending downward, with outwardly inclined having openings for the insertion of electrical cables, a nutra connecting rod adapted to be electrically connected to the housing of the load center, a main insulating lug having longitudinally extending compartments in the form of a through and first and second legs of support to place on the neutral union bar, a base board that has a surface with poles integrally formed with a lower cut extending around its periphery to secure a component of the load center to the surface by heat appli cation, the surface having two integrally formed, spaced-apart wall members extending upwards from the surface forming a barrier between the common connecting bars of the load center, the surface having a tongue with a sloping lower edge and a tip extending from a lateral edge of the tongue to be captured by the lances found in the housing of the load center, the surface having a neutral bar wire guide, comprising a wall extending upwardly from the surface member and having semicircular grooves extending therethrough on an upper surface to receive and guide a return wire into an opening in the neutral bar, the surface having a base for mounting modular extension extending from the lower end wall of a switch support rail to receive a modular extension base board, the mounting base has a shaped, trapezoidal slot for coupling by a correspondingly shaped ramp of the base board Modular extension, the modular extension mounting base further has a slot to receive a flexible clamping hook from the modular extension base board to secure the modular extension base board to the wall board.

Description

BASE BOARD SYSTEM ADJUSTED TO PRESSURE FIELD OF THE INVENTION The present invention relates generally to electrical load centers and more particularly to an improved load center and load center components.

BACKGROUND OF THE INVENTION Electric load centers experience many limitations. Mounting the various components of the load center, such as the cut-out panel for the metal housing of the load center, often requires an electrical to align the holes in these components, insert screws through the aligned holes and screw each screw in the holes. Such activities are time consuming and often not successful on the first attempt and have to be repeated several times. According to one aspect of the present invention, there is provided an attachment fastener of the push screw inwards for the metal housing, which allows an electrical to easily secure the guard to the metal housing.

Sometimes an overpressure condition is created within a load center, which can cause the door of the prior art load centers to be forced to open. According to one aspect of the present invention, a new and improved bolt or bolt is provided which, during the overpressure condition within the load center, causes the bolt to engage the bolt receptacle in the trimmed panel even more securely, in such a way that the door does not open. Because load centers are constructed in various sizes, for each size of load center built by a manufacturer, a separate inventory of base boards have been manufactured and maintained. Therefore, there is a need to develop base boards which are adaptable for various sized load centers and which are relatively inexpensive to manufacture. This need is partially met by the production and use of baseboards. Alternatively, piece of auxiliary, modular, individual sub-base boards are built for interconnection to realize the switch of load centers of length *, adjustable. Because the angular mounting of the components is not well suited for robotic assembly, some prior art baseboards and modular extensions have been adapted to be vertically loaded downwardly to couple the portions of the baseboard, or have been adapted to be connected horizontally or laterally to couple the portions of the base board. Such joining methods and modular construction can not be advantageous and can result in an imprecise separation between the connected modular pieces, which can affect the subsequent assembly and installation of the components to the base board and the base board to the housing. In accordance with one aspect of the present invention, a new and improved modular base extension board and base board are provided, which can be robotically assembled, but do not need to be robotically assembled in only one vertical drop down mode or a lateral mode and which reduce the possibility of misalignment and inadequate separation between the connected modular pieces. Securing the base board to the housing, it often consumes time and is bulky. Of: according to one aspect of the present invention, an improved base board having mounting characteristics is provided, which facilitates the mounting of the base board to the housing, thus saving time and labor. It is well known in the art to provide an electrically insulating barrier between the common connection bars of the load centers. In accordance with one aspect of the present invention, an improved base board is provided which integrally formed an insulating, electrical barrier between the common connecting rods, which increases the protection of the presence or formation of an archway, as well as decreases the possibility of holding the arch, once it has occurred. Common connection bars have been secured to the base board by common fastening devices, such as screws, bolts and snap fasteners (U.S. Patent No. 4,536,823) which can be tedious, time consuming in application , not economic, it requires extra parts and more importantly, it can impart stresses to the component that is secured and adversely affect the structural integrity of the component. Applying ultrasonic energy to the posts, which are integral parts of a plastic base board as a means of deforming the post to secure the connection bars common to the plastic base board, is well known (US Patent 4,118,754 ). Stacking with heat as a means for securing the components to a plastic base board can be advantageous in overcoming the disadvantages set forth in the above of the common fastening devices, but imparts tensions which are concentrated on the surface of the board. base, where the base of the pole intersects the base board to form the corners. Such tension can significantly damage the integrity of the connection causing a fracture of the post, loss of the integrity of the connection and a decrease in the service life of the base board and the load center. In accordance with one aspect of the present invention, an improved base board is provided having integrally formed poles for securing therein components, such as common connecting rods and the like by heat stacking, which reduces the stresses imparted to the poles. and the base boards of the stack with heat. As is well known, it has been difficult for the installers to secure the cables back to the neutral bars of the charging centers of the prior art, because it is generally difficult to see the holes in the neutral bar within which the cables go to be placed. To improve the visibility of the holes in the neutral bars within which the return wires of the power circuits are to be inserted and secured and thus facilitating the connection of the neutral return wires to the neutral bars by the installer electrical, according to one aspect of the present invention, an improved neutral bar is provided, which allows observation of the electrical connector openings placed in the side walls, when viewed either directly on the top or side.

Also, the prior art joining methods between the neutral bar and the base board are unsatisfactory. According to one aspect of the present invention, the neutral bar is adapted to allow simplified assembly and mounting to the base board. This is done by providing a configuration of the neutral bar and an improved base board to which the neutral bar is attached, which does not require the use of screws or other separate fastening devices, so that the number of components in the bar is reduced. center of load and facilitates the assembly of the neutral bar to the base board. In addition, to further facilitate the installation of the wires back to the neutral bars of the load center, according to one aspect of the present invention, an improved base board having an integrally formed neutral bar wire guide is provided, which helps the electrician or the installer in guiding the wires of the power distribution circuits in the openings of the electrical connector in the neutral bars. In accordance with another aspect of the present invention, an improved neutral clamping bar is provided, which connects the neutral bars together. Some prior art charging centers are not grounded because the installer or the user does not comply when doing so. However, there is a need to ensure that there is no potential difference between the neutral bar and the ground. According to this aspect of the present invention, the neutral clamping bar is adapted to be able to be electrically connected to the outer metal housing of the load center, thereby eliminating any potential difference between the neutral bar and the earth of the load. load center. Since each power company provides service that maintains the neutral potential to near zero volts, the function of connecting the neutral part of the load center to the ground is performed by electrical connection of the neutral union rod to the outer metal housing . In accordance with one aspect of the present invention, a new and improved insulating terminal lug or barrier is provided between the incoming service and the other components of the load center operating to: isolate each of the main terminal lugs of the connecting rod neutral common, the neutral union rod and the lug or neutral lugs; reduces shortening or incidental energization of live conductors both during installation and subsequent operation; and maintaining the oversurface and through air separation for cooling and expansion of the main terminal lugs.

BRIEF DESCRIPTION OF THE INVENTION According to the invention, the load center housing is adapted to receive and is fitted with a push screw fastening accessory comprising an open end of a U-shaped structure formed by the bending of a piece of sheet metal what's wrong with it; (a) an upper surface having two tabs formed therein, facing each other and directed inwardly and downwardly, each of the tabs having a free end that forms an opening therebetween to receive the threads of a screw and which are flexed by axial pressure to form a one-way opening, the upper surface further has two projections. that extend outward; and (b) two side walls extending downwardly and substantially orthogonally from the top surface, each of the side walls having a tongue formed therein and directed outwardly and upward to hold an edge of the hole, between the tongue directed upwards and outwards and the projection that extends outwards. The bolt of the load center door comprises a one piece molded member, placed in an opening in the. uerta, the member of a piece has a flat upper surface with an indentation to open the bolt, a body portion extending from a lower side of the flat surface, which is slidably received in an opening in the door, the body portion having a flexible tongue extending in an upward direction at an angle away from the body and towards the free edge of the door. The one-piece molded member further includes a hook positioned from the underside of the upper part, the hook having a free end extending toward the tongue of the body for engagement of an edge on the underside of a portion of a panel of trimming of the load center and which is adapted to form an opening adjacent to the opening in the door. The tongue pushes the door latch towards the first edge of the door, keeping the hook engaged in a deviated manner with the edge of the lower side of the portion of the trim panel adapted to form the opening. The base board of the load center is an integrally formed pressure-adjusting base board, comprising a one-piece molded member, having a flat surface for mounting the common connecting rods, at least one support rail of the switch extending upward from the flat surface to support the switches in the load center, the switch support rail has at one end an upper end wall and at a second end a lower end wall, the wall of The lower end is adapted to have a slot with an upper edge. The press fit base board has at least one modular extension mounting base extending from the lower end wall to receive a modular extension base board, to extend the length of the press fit base board . The modular extension mounting base comprises an upper wall and two side walls and a front wall and a rear wall which is arranged to form a hollow rectangular box, the rear wall is formed by the end wall of the switch support rail, the upper wall and one of the two side walls of the modular extension mounting base having a trapezoidal shaped slot extends therethrough for coupling by a correspondingly shaped ramp of the modular extension base board to align the Modular extension base board to base board by snap fit. The upper wall of the modular extension mounting base further includes an opening for passing through it a flexible adjusting hook extending from the modular extension base board to engage the upper edge of the groove formed in the wall The lower end of the switch support rail and thus ensures the modular extension base board to the base board of pressure adjustment. The base board of the load center comprises a flat surface for mounting the common connection rods, the flat surface has a tongue extending from one edge of the flat surface, the tongue has a sloping bottom edge and a tip which extends on a lateral edge. The base board further has lugs extending from the flat surface and positioned towards opposite sides of the base board, each of the lugs having an opening for the passage of a screw. The load center housing has a lance formed from a rear wall, the lance has a free end positioned spaced apart from the rear wall and inside the housing interior to capture the tongue of the base board, the housing further has a hole in the housing. rear wall to receive a screw. As the base board is being mounted to the housing, the sloped bottom edge of the tongue is captured between the lance formed in the rear wall of the housing and the lower surface of the rear wall and the tip are engaged by an upper edge of the housing. the tongue to stop the vertical movement of the base board, while the lugs of the base board are placed in abutting contact with the inner surface of the rear wall for mounting by a screw through the opening and into the correspondingly located hole in the housing. The base board of the load center comprises a flat surface for receiving first and second common connecting rods, the flat surface having two substantially parallel, spaced apart wall members integrally formed with and extending substantially orthogonally upwards from the flat surface to form a double-walled barrier, continuous between the first common connecting rod and the second common connecting rod. The base board of the load center comprises a surface to which a selected component of the load center is to be assembled, the surface having at least one post formed integrally for heat-stacking hammering to secure the selected component to the board of base, in which the integrally formed post has a lower cut in a toroidal shape that extends around a periphery of the post at the intersection with the surface of the base board. According to one aspect of the present invention, there is provided a neutral bar having an elongated central body portion with a trapezoidal cross-sectional area with the side walls extending downward tilting outwards, the side walls having a plurality of openings for the insertion of electric wires, an upper portion extending from the central body portion and having a plurality of internally threaded holes in at least one of which, is in communication with a corresponding opening of the plurality of openings in the side walls and a base portion extending from the central body portion to mount the base board. The base board of the load center; 'comprises a surface member for mounting the components of the load center of a channel for mounting a neutral bar having a plurality of electrical connector openings for receiving the neutral return wires, the surface member further includes a bar wire guide integrally formed neutral, comprising a wall extending vertically from the surface member, the wall having semicircular grooves extending therethrough on an upper surface, each of the semicircular grooves for receiving a return wire and guiding the return wire through it and into a preselected aperture of the plurality of electrical connector openings in the neutral bar. An improved neutral tie rod for connecting together the neutral bars of a load center, having an outer metal housing, the neutral tie rod comprises: (a) a center portion having two laterally extending ends, displaced vertically, each end has an opening for receiving a screw to secure each end to a neutral bar; (b) a pair of raised first members, each pair of the first raised members that are placed between the center portion and one of the ends and adapted to form a neutral, shunt wire lug having a hole positioned horizontally To receive a neutral bypass wire, the neutral bypass wire lug further has an internally threaded hole that extends vertically in communication with the horizontally placed hole, the internally threaded hole extends vertically to receive a threaded fastening screw for securing the "branch" neutral wire - (c) a second raised member positioned between one of the pair of first lifting portions and one of the laterally extending ends, displaced vertically, the second raised member is adapted to form a neutral cable lug that has a hole placed horizontally to receive a neutral cable, the ear The neutral wire cable also has an internally threaded hole that extends vertically in communication with the horizontally placed hole, the internally threaded hole extends vertically to receive a threaded fastening screw to secure the neutral cable. The neutral connecting rod can be electrically connected to the outer metal housing of the load center. An insulating main lug for an electrical load center, comprising: a first and a second longitudinally extending compartment, formed in a through manner, each of the first and second compartments comprising a horizontally placed platform from which two vertical walls extend having first edges, which form a first open end and which have second edges which form a second open end that faces opposite; a first support leg extending downward from the first edges forming the first open ends; a second support leg extending downward from the second edges forming the second open ends, - the first support leg is spaced apart and substantially parallel to the second support leg to form a laterally extending, open space between them and below the platforms for placement on a neutral union rod of the load center.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a pre-emptive view of the load center incorporating the principles of the present invention; Figure 2 is a plan view of the outer housing of the load centilor shown in Figure 1; Figure 3 is a plan view of the trimmed panel, which encloses the outer housing shown in Figure 2; Figures 4A, 4B and 4C are top and side view of an inward push screw fastener; Figure 5 is a front view of the door mounted to the trim panel shown in Figure 3; Figures 6A and 6B are perspective views of the door lock from above and below, respectively; Figure 6C is a side view of the door bolt; Figure 6D is a sectional view of the door bolt shown in Figure 6A, taken along the line 6d-6d; Figure 6E is a sectional view of the bolt of the door mounted to the door and secured closed to the guard of the door; Figure 7 is a perspective view, isolated from the base board shown in Figure 1; Figure 8 is a top plan view of the base board shown in Figure 7; Figure 9 is an enlarged plan view of a base or mounting leg of modular extension of the base board shown in Figures 7 and 8; Figure 10 is a sectional view of the modular extension mounting base taken along line 10-10 in Figure 9; Figure 11 is a sectional view of the modular extension mounting base, taken along line 11-11 in Figure 9; Figure 12 in a top plan view of a modular extension base board, for connection to the base board shown in Figures 7 and 8; Figure 13 is a sectional view of the modular extension base board taken along line 13-13 in Figure 12; Figure 14 is a sectional view of a portion of the modular extension base table, taken along line 14-14 in Figure 13; Figure 15 is an enlarged plan view of the mounting base of the modular extension base board shown in Figure 12; Figure 16 is a sectional view of a portion of the mounting base taken along line 16-16 in Figure 15; Figure 17 is a sectional view of a portion of the mounting base taken along line 17-17 in Figure 15; Figure 18 is a sectional view of the base board taken along line 18-18 in Figure 8; Figure 19 is a sectional view of the housing, taken along line 19-19 in Figure 2; Figure 20 is a perspective view of the interior components of the load center in Figure 1, showing the base board with the switches removed; Figure 21 is an enlarged plan view looking down at a portion of the base board shown in Figure 20, taken along line 21-21; Figure 22 is a sectional view taken along line 22-22 in Figure 21 showing a corrugated double wall barrier between the common connection bars; Figure 23 is a sectional view taken along line 23-23 of the integrally formed hollow post, shown in Figure 8; Figure 24 is a sectional view taken along line 24-24 of the integrally formed solid post shown in Figure 8; Figure 25 is a cross-sectional view of a neutral bar taken along line 25-25 in Figure 20; Figure 26 is a top view of '-the neutral bar shown in Figure 20; Figure 27 is a cross-sectional view of snap-fit, flexible extending vertically upwards, taken along line 27-27 in Figure 8; Figure 28 is a side elevation view of the wire guide of the neutral bar, taken along line 28-28 in Figure 8; Figure 29 is a sectional view of the neutral tie rod, taken along line 29-29 in Figure 30; Fig. 30 is a top view of the neutral tie rod shown in Fig. 20; Figure 31A is a perspective view of the main insulator tab shown in Figures 1 and 20; Figure 31B is a top view of the main isolation tab; Figure 31C is a sectional view of the main insulator tab, taken along the line 31C-31C in Figure 3 IB; Figure 31D is a rear elevation view of the main insulator tab shown in Figure 31A; and Figure 31E is a side view of the main insulator tab shown in Figure 31A.

DETAILED DESCRIPTION OF THE INVENTION With reference to the drawings, a load center for use in residential or commercial light applications is indicated in Figure 1 by the reference number 1. The load center 1 includes a housing 10, a trim panel 5Q, which supports the base board 200 mounted thereon, the door 80, the door latch 120, the common connection bars 400 and 440, the neutral bars 500, the connecting rod 550 neutral, the main lugs 420 and 460, the neutral lug 574, the main 600 insulation lug and the distribution switches. Although not shown, the load center 1 may alternatively include a main circuit breaker in place of the main, direct lug connectors 420 and 460 which connect the input service or main lines to the components of the load center and the which function to provide a means to interrupt the power to the load center. With reference to Figure 2, the housing 10 comprises a rear panel 12 and four integral side walls 14, 16, 18 and 20 which end in peripheral rims turned inwards 22, 24, 26 and 28 respectively, surrounding a open front of housing 10. Housing 10 is typically fabricated from a sheet of metal in a series of operations including cutting, pre-forming, forming and welding. The housing 10 is typically installed between the wall posts of a construction partition, such that the open side of the housing is flush with the division of the exterior surface. The housing 10 is covered by a trim panel 50 shown in Figure 3 to adjust level with the housing and division. The trim panel 50 is attached to the housing 10 with fasteners, such as screws, which pass through the holes 52 formed in the trim panel and peripheral ridges 22 and 26 of the side walls 14 and 18 shown in FIG. Figure 2. The cutting panel 50 has an articulated access door, secured by a bolt which allows access to the interior of the load center, to allow the manipulation of the user that manipulates the actuation of the switch located in the load center. When installing a trim panel for a prior art housing, the electrician generally has to align the holes formed in the trim panel with the corresponding holes located in the housing, insert the screws through the aligned holes and screw each screw in the housing. This work is time consuming and often not successful on the first attempt and has to be repeated several times. In accordance with one aspect of the present invention, the housing 10 is adapted to receive and is fitted with an attachment fastener of a thrust screw, which allows an electric fasten the trim panel 50 to the housing 10 by pushing only one screw to through the opening 52 in the trim panel and into the push screw holder mounted on a housing rim. With reference to Figures 4A, 4B and 4C, the push screw fastener 40, is shown and comprises an open end, a "U" shaped structure, formed of a single piece of sheet metal, where the shape in U is formed by folding the metal sheet to form an upper surface 41 and two side walls 43 extending from the upper surface. The upper surface 41 has two projections 42 directed outwards. A single-way opening 49 is formed in the upper surface 41 by two tabs 44 directed inwardly and downwardly., as discussed more fully in the following, to receive a threaded fastener. On each of the opposite side walls 43 there is a separate cutting tab 46 directed outwards and upwards. An attachment 40 of the thrust screw is inserted into the correspondingly shaped holes 30 in the flanges 22 and 26 (shown in Figure 2). The outwardly extending projections 42 help in securing the push screw holder 40 in place, in the hole 30 in the housing holding the edges of the hole 30 between the outwardly extending projections 42 and the tabs 46 directed toward up and in At the time of installation of the trim panel 50 to the housing 10, the openings 52 of the trim panel are aligned with the push screw fasteners 40 in the shoulders 22 and 26 of the housing 10, and a screw is pushed through each of the openings 52 of the clip of the trim panel and within the one-way opening 49 in each of the push screw fasteners 40. • "The cut tabs 44 separated in and out from the push screw holder 40, act as fingers of a loaded spring or spring springs, which are deflected by the axial pressure that is exerted by a screw that is pushed inside the push screw holder. The free edges 47 of the tongues 44 forming the opening 49 engage the threads of the screw, thereby preventing linear withdrawal (i.e., pulling the screw outward in the direction opposite the direction of insertion) without rotation of the screw in an anti-clockwise direction. In the case of an overpressure condition within a load center, which may be caused for example by a short circuit fault, the door of some designed load centers of the prior art, may be caused to blow the door . More specifically, the door can be arched outwards which can cause the door and therefore the door-mounted lock of the prior art designs to move away from the coupling with the bolt receptacle, generally located in the guard until the bolt of the door comes to uncouple from the bolt receptacle allowing the door to be opened pushed by the overpressure condition. In accordance with one aspect of the present invention, a new and improved bolt is provided which, during an overpressure condition within the load center, causes the bolt to engage the bolt receptacle on the guard even more securely, such so that the door does not undock and open. With reference to Figure 5, the door 80 is shown mounted to the trim panel 50 by the hinges 82. Mounted on the surface 84 of the door 80 is the door lock 120 shown in Figure 6A. The door latch 120 is a one piece molded member, comprising an upper part 122 having an indentation 124 for coupling the operator's finger to open and close the bolt 120. The bolt aperture 120 is made by the latch bolt. the sliding door 120 along the surface 84 of the door 80. As shown in Figure 6B, extending from the lower side 126 of the upper part 122 is a body portion 128, which has a flexible tongue (or a spring-like deflection member 132, which extends in an upward direction from a lower portion of a side wall 130 of the body portion 128. Extending separately from the underside 126 of the upper portion 122 there is generally a "L" shaped fixed hook (or jaw) 134. The free end 136 of the hook 13'1 extends laterally in the direction of the tongue 132. The door 80 has a first cut or opening 86 (shown in FIG. Figure 5) dimensioned to allow the body portion 128 of the bolt 120 to pass through the door 80. As shown in detail in Figure 6E, there is a flange 90 on the door 80 formed by the bending of the metal cut by the lances for the flange 90. The tongue 132 rests on the flange 90 of the door, 80. The lower side 126 of the upper part 122 is placed on the surface of the front part of the door 84. The detent latch 138, shown in Figure 6D, which extends from the lower side 126 of the bolt 120 is placed against the depression 92 of the first cut 86, as shown in Figure 5. A second cut 88 in the door 80 is sized to allow the fixed, L-shaped hook 134 to pass through the door 80. The portion of body 128 of door latch 120 is adapted to form a track 144 on each of two side walls 140 to allow bolt 120 to slide along the surface of the front of door 84 guided by the edges 94 (shown in Figure 5) of the first cut 86 of a coupled position shown by Figure 6E to an uncoupled position. Extending from each of the side walls 140 of the body 128 are the inverted "C" shaped projections. The tracks 144 are formed between the lower side 126 of the upper part 122 and the upper edge 146 of the projections 142 formed in inverted "C". The inverted "C" shaped projections 142 fit in the notches 96 shown in Figure 5 in the first cut 86. After the installation of the door lock 120 in the door 80, the projections 142 in the form of "C" inverted are not aligned with the notches 96, which therefore prohibit the removal of the door lock 120 from the door 80. With reference to Figure 6E, the door 80 is shown secured in a closed position and locked by the lock 120 of door with the L-shaped hook 134, which passes through the second cut 88 in the door 80 and through an opening 54 in the cut-out panel 52 (Figure 3) to attach the edge of the lower side 55 of the opening 54. To uncouple the bolt 120 from its inactive closed position to allow the opening of the door 80, the operator places his finger on the indentation 124 of the upper part 122 and slides the bolt towards the "free" end of the door. gate 80 (that is, in one direction separating from the joints of the door). As the bolt 120 slides along the surface 84 towards the free end of the door 80, the flexible tongue (or base member) 132 is compressed by the flange 90 thereby causing the hook 134 in the form of "L", which extends from the lower side 126 of the bolt 120 and which is with the surface inward, towards the hinges 82, to move out of engagement with the lower side 55 of the door 80 formed around of the opening 54 and in vertical alignment with an opening 54, in such a way that the L-shaped hook 134 can freely pass through the opening 54, thereby allowing the opening of the door 80. The lock 120 is held in a locked position by the flexible tab 132 pressing against the flange 90. The pressure of the flexible tab 132 against the flange 90, which holds the bolt 120 in a closed position, is maintained by a detent 138 extending from the bottom side 1 26 of the bolt 120. In this way, the bolt 120 is in a closed, deflected position and since the L-shaped fixed hook 134 is facing inward towards the hinges 82 of the door 80, the bolt 120 remains in a closed position, deflected even if the door 80 flexes outward during an overpressure condition within the load center 1. Placed inside the housing 10 there is a base board 200 to which the various components of the load center are mounted . The base board 200 is made of an electrically insulating material, which can be injection molded or extruded. An example of such material is a thermoplastic material sold under the trademark Noryl by General Electric Company. Since the load centers are built by a manufacturer in various sizes, a separate inventory of baseboards have to be manufactured and maintained for each size of the load center.

To decrease the expense and the need to maintain various sizes and base boards, an extruded base board of the type described in U.S. Patent Nos. 4,449,296 entitled "Method of Forming Electric Distribution Panel", 4,536,823 entitled "Electric Panel Board Having An Improved Extruded Basepan Configuration ", 4,740,865 entitled" Extruded Three-Phase Basepan Configuration for a Load Center "and 5,081,560 entitled" Load Center Enclosure "were introduced. Also, one or more pieces of auxiliary, modular, individual base board have been constructed for interconnection to form adjustable length switch load centers. Such modular base board parts are shown in U.S. Patent Nos. 4,646,198, 5,450,282 and 4,251,851. Due to the difficulties involved in the robotic assembly of the load center components, which require angular mounting, particularly molded base boards and modular extensions to provide variable length base boards and due to difficulties in mounting or securing the components to the base board, the modular extensions have been designed and manufactured in the prior art to avoid the need for angular mounting. That is, the modular extensions have been adapted to be loaded vertically downward to couple the portions of the base board or have been adapted to be connected horizontally or laterally to couple the portions of the base board. Such prior art joining methods and modular constructions experience possible misalignment and inadequate separation between the connected pieces, which may affect the subsequent assembly and installation of the components to the base board. Therefore it would be an advantage over the prior art to have components of the modular extension base board, which have not been assembled solely in either a downward, vertical or a laterally connected mode, which reduces the possibility misalignment and inadequate separation between the modular pieces connected, and which, however, can be assembled robotically. With reference to Figures 7 and 8, there is provided a pressure adjusting base board 200 having a surface 202 on which the common connection bars 400 and 440 are to be mounted and the switch support rails 204, from which the hooks 206 of the switch support extend for the mounting and support of the switches. Each of the rails 204 of the switch bracket has an upper end wall 208 and a lower end wall 210. According to one aspect of the present invention, an improved base board 200 is provided, which has a mounting base 212 of modular extension, which extends from the lower end wall 210 and on which a modular extension base 300 board (shown in Figure 12) can be mounted to extend the length of the press fit base 200 board and thus allowing a larger number of switches to be installed within the load center 1. The modular extension base board 300 is also made of an electrically insulating material, which can be injection molded or extruded such as Noryl. With reference to Figures 9 and 10, the modular extension mounting base 212 is in the form of a rectangular, hollow box having an upper wall 214, two side walls 216 and 218, the front wall 220 and a formed back wall. by the lower end wall 210 of the support rail 204 of the switch. Extending between the modular extension mounting base 212 and from the lower edge of the surface 202 is a depressed platform 240 for mounting a slotted edge 332 for engagement of the upper surface 302 of the modular extension base board 300. The trapezoidal alignment slot 222, formed in the upper wall 214 and the side wall 218 of the base 212 (shown in Figure 9 and best seen in Figure 11) is provided to be coupled by an alignment chute 304 correspondingly formed of the extension 300 base board modular (shown in Figure 13 and best seen in Figure 14) and therefore pull the modular extension base board 300 towards and align it with the pressure adjusting base board 200, when the base board 300 of Modular extension is mounted to the 200 pressure-adjusted base board. This suitably places the modular extension base board 300 to the press fit base board 200 to secure them together as described more fully in the following. To secure the modular extension base board 300 to the press fit base board 200, the top wall 214 of the mounting base 212 has an opening 224 to allow a flexible, snap hook 306 (Figures 13 and 14) of the modular extension base 300 board, pass and engage an upper edge 211A of the groove 211 formed in the end wall 210 (Figure 10) of the support rail 204 of the switch, when the modular extension 300 base board is mounted to the press fit base board 200. The modular extension base board 300 is configured to be substantially similar to the press fit base board 200 in providing, for example, an upper surface 302, the support rails 308 of the switches, the switch support hooks 310, the barrier 334 of the corrugated, double-walled common connection bar, formed integrally with the solid posts 342 and formed integrally with the po stes 344 hollows and mounting tabs 336 (for mounting the pressure adjusting base board 200 and the modular extension base board 300 to the metal housing 10 (Figure 12). The modular extension base board 300 includes switch support rails 308, which have a cross-sectional shape of an inverted "U" (Figures 13 and 14). On an interior wall 312 of the switch support rail 308 at the proximal end of the modular extension base board 300, which is to be attached to the lower end of the base board 200, is a trapezoidal alignment ramp 304 ( Figures 13 and 14) which is complementary in shape and size to the trapezoidal alignment groove 222 and positioned in such a way that the modular extension base board 300 is mounted to the pressure adjusting base board 200, the ramp 304 in a trapezoidal shape is guided by the trapezoidal groove 222. initially in a -x downward direction or an address in the Z plane (shown by the arrows "Z" in Figure 7) and then laterally or horizontally in an X direction (shown by arrows "X" in Figure 7). This causes the modular extension base board 300 to be brought into abutting contact alignment with the press fit base board 200. At the same time, the flexible adjustment hook 306 (Figures 13 and 14) passes through the hole 224 (Figure 9) and engages the edge 211A of the slot 211 (Figures 10 and 11) in the lower end wall 210 of the rail 204 of switch support, whereby the base board 300 of modular extension is secured to the base board 200 of snap fit. The result of causing the modular extension base board 300 to move in both of a vertical Z direction and virtually simultaneously in a horizontal X direction during the mounting of the modular extension 300 base board, before securing it to the control board. 200 pressure adjusting base, there is a closer and safer fit between the modular extension 300 base board and the 200 snap-fit base board, which in turn allows for the assembly of the components of the center load on the assembled base board. The distal end of the modular extension base board 300, the end of which is further apart from the lower end of the pressure adjusting base board 200, is configured to be substantially identical to the lower end of the press fit base table 200. This configuration permits the successive joining of the base boards 300- of modular extension to each other. In this way, with reference to Figure 12, the base board 300 of modular extension, has at its distal end two modular extension mounting legs 314, each in the form of a rectangular hollow box having an upper wall 316 , two side walls 318 and 320, the front wall 322 and a rear wall formed by the end surface 309 of the switch support rail 308. A trapezoidal alignment slot 324 is formed in the upper wall 316 and the side wall 320 in the mounting legs 314 (Figures 15 and 16). The top wall 316 has an opening 326 and an end wall 309 of the switch support rail 308, has a slot 328 having an upper edge 328A (as does the modular extension mounting base 212 of the base board 200) . Extending between the modular extension mounting legs 314 is a platform 330 depressed. - These elements and features of the pressure-adjustable base board and the modular extension base board, facilitate the robotic assembly with each other, while providing a secure fit with each other. According to another aspect of the present invention, the portion of the housing to which the base board is to be secured and a corresponding portion of the base board, which is used to secure the base board to the housing, are improved to decrease the costs of its manufacture and facilitate the assembly of the base board to the housing.

Referring to Figures 7 and 8, the base board 200 is shown having lugs 226 placed on opposite sides and each lug has an opening 228 for mounting by a screw to an orifice 32 correspondingly positioned in the housing 10. base board 200 - adjustable to fit is also provided with tabs 230 extending laterally from the outer wall 209 of each switch support rail 204 • (Figures 8 and 18). Each tab 230 has a lower edge 232 inclined to capture between a lance 34 formed in the rear wall 12 of the housing 10 and the inner surface of the rear wall 12. The tongue 230 has a tip 234 extending laterally from a side edge, which is stopped by the upper edge 36 of the lance 34, whereby it stops the vertical movement of the base board 200 as it is installed in the housing 10 (Figure 2). The lances 34 are stamped or cut from the rear wall 12 of the housing 1Q and flex inside the housing 10 as shown in Figure 19. The free ends of the lances 34 face each other and capture the lower edge 232 inclined from the tongue 230, when the base board 200 is being installed inside the housing 10. The tips 234, which extend from the side of each tab 230 are engaged by the upper edge 36 of the lances 34 to stop the vertical movement of the base board 200 during the installation of the base board to the housing 10, while the lugs 226 of the base board 200 are placed in abutting contact with the inner surface of the rear wall 12 of the housing 10. The base board 300 of modular extension, is also provided with the tabs 336 that extend laterally from the outer wall 311 of each switch support rail 308 (Figure 12) and are in any other structurally and functionally the same way as the tabs 230 of the board of 200 pressure adjustment base. Each tab 336 has a sloping lower edge 338 and a tip 340 extending laterally from the side edge 311 to capture between a lance 34 and the inner surface of the rear wall 12. When the modular extension 300 base board has been mounted and secured to the base-200 adjustment-to-pressure board, the tabs 336 and tabs 230 are captured by the lances 34. The base board 300 of modular extension, assembled and the base board 200 of snap fit is installed inside and secured to the housing 10 in the same way that the base board 200 is only installed in the housing 10. The free end of the lance 34 captures the lower edge 338 inclined and the upper edge 36 stops the vertical movement of the base board 200 by the capture of the tip 340. The openings 228 in the lugs 226 are brought into alignment with the holes 32 correspondingly positioned in the rear wall 12 and receive a screw, and which retains the upper end of the base board 200 to the housing 10. The common connection bars 400 and 440, which function to interconnect the supply line with the distribution switches, have common connection bars 402 and 442, flat with integrally formed tongues or contact blades 404 and 444, respectively. The tabs 404 and 444 extend in parallel planes perpendicular to the longitudinal axis of each common connecting bar and are aligned in a row in a face-to-face relationship, interspersed as shown in Figure 20. The distribution of the switches are electrically connected. to the free end 406 and 446 of the tabs 404 and 444, respectively, and are supported on the base board 200 at one end by the switch support rail 204 and at its other ends by the barrier 250. The free ends 404 and 446 of each of the tongues 404 and 444 are mechanically and electrically connected within the recesses in the distribution switches and prevent a short line to line between a tongue of the connection bar 400 from occurring to a tongue of the connecting rod. common 440. Since the placement of the distribution switches on the tabs of the common connection bars can not avoid the possibility of In a line-to-line short that occurs between a busbar common to the other common busbar, it is known in the art to provide an electrically insulating barrier between common busbars, which increases the path distance of the bus. short circuit, so it decreases the possibility that a short will occur. According to one aspect of the present invention, an electrically insulating, wavy, double-walled barrier 250 between the common connecting rods 400 and 440 is provided, which increases the protection of a short occurrence, as well as decreases the possibility to hold the short, once it has happened. With reference to Figures 20 and 21, the electrically insulating, wavy, double-walled barrier 250 is shown as consisting of the walls 252 and 254 integrally formed with and extending substantially orthogonally upward from the flat surface 202 of the base board 200. and they are placed on the 200 base board to provide a double wall physical barrier, continues between the common connection bars 400 and 440. The electrically insulating, wavy, double-walled barrier 250 doubles the distance an arc must travel between the common 402 and 442 flat connections, which decreases the possibility of the track of the arch may occur when compared to prior art devices. In addition, doubling the distance that an arc must travel, also decreases the possibility of tracking the arc, once it has occurred, that is capable of reoccurring. The path of the circuit that the arc must move on and around the walls 252 and 254 of the barrier 250 as represented by the dotted line in Figure 22 also decreases the possibility that an arc will follow the track due to the length of the arc. the path that follows the track of the potential arc. Common connection bars have been secured to the base board by common fastening devices such as screws, bolts and snap fasteners (US 4,536,823) which can be tedious, time-consuming, non-economic, require extra parts and more Importantly, it can impart stresses to the component that is insured and adversely affect the structural integrity of the base board. The application of ultrasonic energy to the poles, which are integral parts of a plastic base board as a means of deforming the post to secure the common connection rods to the plastic base board is well known (United States Patent 4,118,754). Stacking with heat as a means of securing the components to a plastic base board can be advantageous in overcoming the disadvantages set forth in the above of the common fastening devices, but imparts tensions which are concentrated on the surface of the base board , where the base of the pole intersects the base board to form corners. Such tension can significantly damage the integrity of the connection leading to a fracture of the post, loss of the integrity of the connection and a decrease in the service life of the base board and the load center. According to one aspect of the invention, there is provided an improved base board having integrally formed poles for securing to them components such as common connecting rods and the like by heat stacking, whose improvement avoids imparting stresses to the poles. With reference to Figure 8, the base board 200 is shown having integrally formed solid poles 242 and integrally formed hollow poles 244 for the mounting of the common connecting rods 400 and 440. With reference to Figure 23 (which is a sectional view of a hollow post and the base board), the hollow post 244, which is formed integrally with the surface 202 of the base board 200, is shown having a lower cut 246 in a toroidal shape extending around the periphery of the hollow post 244 at its intersection or junction with the surface 202. The lower cut 246 of toroidal shape eliminates the pointed corners in the interconnection or joint between the hollow post 244 and the surface 202, thereby reducing the concentration of the tension, which can make hollow post 244 susceptible to fracture of surface 202, due to heat stacking. As shown in Figure 24, the solid post 242 similarly has a lower cut 246 of toroidal shape, which extends around its periphery at its intersection with the surface 202. The lower cuts 346 of toroidal shape are similarly provided with posts 342 integrally formed solids and hollow poles 344 integrally formed of the modular extension 300 base board (Figure 12). With reference to Figure 20, the divided neutral bars 500 each of which constitute a common electrically conductive joint for the connection of the return wires of the distribution circuits to the return of the main power line are shown mounted on the channels 260 of the base board 200. In accordance with one aspect of the present invention, to improve the visibility of the openings of the electrical connector of the neutral bar in which the return wires of the distribution circuits are to be inserted and secured, and therefore facilitates the connection of the return wires to the neutral bars by the electrical installer, each neutral bar has a central portion having a cross-sectional area in generally trapezoidal shape with the side walls inclined outwards. Such a configuration allows the observation of the openings of the electrical connector placed on the side walls of various positions, either as orthogonal or directly above, or from the side. With reference to Figure 25, which is a cross-sectional view of the neutral bar 500 shown in Figure 20 taken along the line 25-25, the neutral bar 500 has a central body portion 510 having a cross-sectional area in generally trapezoidal shape, with the side walls 512 and 514 inclined outwards. The openings 516 of the electric return wire connector are provided in the side walls 512 and 514 of the neutral bar 500. The upper portion 502 of the neutral bar 500 has an upper wall 504 through which a series of holes 506 internally threaded are provided, each of which is in communication with the opening 516 of the return wire connector correspondingly positioned. Placed inside each threaded hole 506 internally there is a fastening screw 508, threaded to secure the return wire to the neutral bar. The placement of the openings 516 in the side walls 512 and 514 of the body 510 of the cross-sectional area of generally trapezoidal shape of the neutral bar 500, allows the installer of the field to visually correlate the particular opening within the which a corresponding electric return wire is to be inserted and subsequently secured by a clamping screw 508. In this way, as shown in Figure 26, when observing the neutral bar 500 orthogonally (i.e. directly above) as shown in FIG. shows, for example in the top view of the neutral bar 500 with the screws 508 removed, each of the holes 506 internally threaded in the upper wall 504 and each of the openings 516 of the electrical connector correspondingly positioned in the side walls 512 and 514 are easily observed and located, so they facilitate the proper insertion and connection of the return wires to the neutral bar. According to one aspect of the present invention, the neutral bar 500 is also adapted to allow simplified mounting and mounting of the base board 200 which does not require the use of screw or other separate fastening devices, thereby reducing the number of components in the load center. Referring again to Figure 25, extending from the central portion 510 of the neutral bar 500 there is a base 520 adapted to have a "T" shaped slot 530, formed by the space "between two mounting rails 522 and 524 , which receives the securing means formed integrally with and extending upwards from the channels 260 of the base board 200. With reference to Figures 7, 8 and 20, the securing means of the base board 200 comprises alignment blocks 262. which extend upwards, which fit within the space between the mounting rails 522 and 524 to align the neutral bar 500 within the channel 260 and the flexible hooks 264 and 266, which extend upwards (Figure 27) which press fit the flanges 526 and 528, respectively, of the mounting rails 522 and 524 (Figure 25) to join the neutral bar 500 to the base board 200 in a bolted manner. The neutral bar 500 therefore it can be mounted quickly and easily to the base board 200 and is retained in place without the need for any additional fastening devices. Although the neutral bar 500 can be manufactured as a molded or cast member, unitary in a preferred embodiment, the neutral bar 500 is fabricated from an extruded metal such as aluminum. To further facilitate the installation of the return wires to the center, load-neutral bars according to one aspect of the present invention, a neutral bar wire guide is provided, which helps the electrician- or installer in sending the return wires of the distribution circuits in the openings of the electrical connector in the neutral bars. As shown in Figures 7, 8 and 20, formed integrally with the base board 200 there are two guides 270 of wire of the neutral bar, each of which comprises a wall 272 that extends vertically upwards from the surface of the 200 base board at the edge of the channel 260 and having semicircular grooves 276 extending through the wall 272 on the upper surface 275 between the outer surface 273 and the inner surface 274, where each semicircular slot 276 are separated from each other by the teeth 277. The structure appears as a serrated edge (Figure 28). Each semicircular slot 276 is positioned to receive a neutral return wire and guide the end of the wire through the slot 276 of the outer surface 273, passes to the inner surface 274 and into an aperture 516 of the preselected electrical connector in the neutral bar 500 (Figure 20). The neutral bar 500 is positioned in the channel 260"of the base board 200, such that each of the openings 516 of the electrical connector, which receive a neutral return wire are aligned with a corresponding slot in the slots 276. semicircular in the wire guide of the neutral bar 270 as shown in Figure 20. The alignment of the semicircular grooves 276 in the wire guide 270 of the neutral bar with the openings 516 electrical connectors in the neutral bar 500, also helps The electrical installer locates the openings 516 of the electrical connector and reduces the time required to connect the neutral return wires The teeth 277 of the neutral wire wire guide 270 function to assist in maintaining electrical insulation between each neutral wire and the ground The use of the neutral bar 500 having a trapezoidal cross-sectional area with the electrically-openings 516 ica easily observable, combined with the guide 270 of the neutral bar wire having semicircular grooves 276, which are aligned with the electrical connection openings 516 of the neutral bar 500, particularly facilitates the connection of the neutral return wires to the neutral bar by the electric installer. . "••. ' An improved neutral connecting rod 550 which connects mechanically and electrically with the neutral bars 500 together is provided in accordance with one aspect of the present invention with reference to Figures 20 and 30 (which is a top view of the neutral junction rod 550 shown in Figure 20 with the other components removed for clarity of illustration), the neutral tie rod 550 is an electrically conductive member for electrically connecting the neutral bars 500 and has a central portion 552 and ends 564 and 566 extending laterally, vertically displaced which are connected by the screws 570 through the openings 568 and within the corresponding internally threaded openings 506 in each of the neutral bars 500. With reference to Figure 29 (which is a sectional view taken along the line 29-29 in Figure 30), the neutral connecting rod 550 is shown as comprising a p first elevated member 554 positioned between the central portion 552 and each end 564 and 566, which are adapted to form a cable lug 556 for receiving, in a horizontally positioned hole 558, a neutral-derivation cable, which is not insured therein by the threaded fastening screw 562 within the internally threaded hole 560 extending vertically. Extending between the first raised member 554 and the end portion 566 is a second raised member 572, which is adapted to have a neutral wire lug 574 for receiving in a hole 576 placed horizontally where the neutral wire enters which is to be secured therein, by the fastening screw 580, threaded with the hole 578 internally threaded . The neutral tie rod 550 is secured to the base board 200 by heat stacking the hollow post 238, which extends upwardly from the base board 200 through the opening 582 (Figures 7 and 8). Ex some applications in which the neutral bar of the load center is not connected or has not been connected to an external earth bar and therefore has not been electrically grounded, however there is a need to ensure that there is no difference of potential between the neutral bar and the ground. According to one aspect of the present invention, in order to eliminate any potential difference between the neutral bar and the earth of the load center, the neutral connecting rod 550 is adapted to be able to be electrically connected to the metal housing 10. outside of the load center. Since each power company that provides the service keeps the potential of the neutral bar at or close to zero volts, the function of connecting the neutral bar of the load center to the ground is performed by electrical connection of the neutral union rod. to the outer metal housing. With reference to Fig. 29, the neutral union connection 550 is adapted to have an opening 586 for accepting a fastener (not shown) which passes through an orifice correspondingly positioned in the hollow post 248 in the base board 200. (Figure 8) and within a hole 38 correspondingly positioned in the housing 10 (shown in Figure 2). Although the neutral tie rod 550 can be manufactured as a unitary or molded member or by cast metal in a neutral tie rod 550, the preferred embodiment is made of extruded aluminum. Typically a removable barrier is provided between the main lugs of the incoming service, which connect the incoming service or main lines to the load center and the rest of the components in the load center. According to one aspect of the present invention, a new and improved main isolator tab 600 is provided to separate the lugs from the main line from the rest of the "components at the load center." The improved insulating main lug functions to: a) isolate each of the main lugs of the neutral tie rod and the neutral lugs; (b) reduce incidental short-circuiting or inadvertent energization of live conductors, both during field installation as well as subsequent operation; and (c) maintaining above the required surface and separation through the air for cooling and expansion of the main lugs. The main insulator tab 600 is an integrally formed member made of an electrically insulating material, which can be injection molded or extruded. With reference to Figure 31, which is an isolated perspective view of the main insulator tab shown in Figure 20, the main insulator tab 600 has two compartments 610A and 610B in the form of a passage for receiving the main lugs 420 and 460. , respectively. Each compartment 610A and 610B are formed of a platform 612 from which extend two vertical dividing walls 614 and 616 having open ends 618 and 620 facing opposite. The open ends 620 provide access for the reception of the connector 408 and 448 of the common connection bar and the open ends 618 provide access for the reception of the ends of the power cables (Figure 31B). The platform 612 of each compartment has a slot 638 that extends transversely for receiving a rail on the underside of the main lugs 420 and 460 to facilitate the placement of each lug within each compartment. Extending down from the edge of each open end 618 and down from the edge of each open end 620 are the substantially parallel support legs 622 and 624, respectively, which connect the compartments together laterally and which raise each break vertically ( Figures 3A, 31C and 31E). The legs 622 and 624 are spaced apart to mount the width of the neutral connecting rod 550 and the suspended compartments 610A and 610B transversely, on the neutral connecting rod, when installed on the base board 200. The 622 leg has a bracket 628, which extends transversely therefrom and is heat-stacked to secure the main insulator tab 600 al'-oste 280 in the base board 200. The leg 624 has a surface 625, which extends laterally between the legs. two compartments 610A and 610B. Extending from the underside of the platform 612 of each compartment, are the bars 636 which are positioned in such a way that when the main insulator lug 600 is installed in the loading center, the bars 636 engage the slots 584 placed and shaped correspondingly on the connecting rod 550 neutral. This works to maintain the position and alignment of the neutral tie rod together with the main insulator tab for heat stacking assembly. Also extending from the underside of the platform 612 and the outer surface 630 of the vertical walls 616 of each of the compartments is an alignment member 632, which forms a slot 634 with the leg 624. When the main insulation tab 600 is installed inside the base board 200, the slot 634 engages the edges 284, 286 and 288 of the vertical barrier member 282 of the base board 200 (Figure 7), which terminates the barrier between (a) the main lugs and the common connecting rod connectors and (b) the neutral lugs and the neutral tie rod as shown in Figure 20. Although the above description and the drawings represent the preferred embodiments of the present invention, it will be apparent to those skilled in the art. the technique, which can be made in it various changes and modifications without departing from the true spirit and scope of the present invention.

Claims (10)

1. A press fit base board, integrally formed for an electrical load center having components including common bus bars and switches, characterized in that it comprises: (a) a one piece molded member having a flat surface for mounting the bars - of a common connection of an electric charge center, - (b) at least one support rail of the switch that extends upwards from the flat surface, to support the switches in the load center, the rail switch holder having at one end a top end wall and at a second end a bottom end wall, the bottom end wall is adapted to have a slot with an upper edge; (c) at least one modular extension mounting base, extending from the lower end wall to receive a modular extension base board to extend the length of the press fit base board; the modular extension mounting baise comprising an upper wall and two side walls and a front wall and a rear wall are arranged to form a hollow rectangular box, the rear wall which is formed by the end wall of the switch support rail , the upper wall and one of the two side walls of the modular extension mounting base having a trapezoidal shaped groove extending therethrough for coupling by a correspondingly shaped ramp of the modular extension base board, for Align the modular extension base board to the pressure adjustment base board; The upper wall of the modular extension mounting base further includes an opening for passing through it a flexible fastening hook, which extends from the modular extension base board to engage the upper edge of the groove formed in the bottom end wall of the switch support rail and thereby securing the modular extension base board to the base board-press fit.

2. A load center, characterized in that it comprises a housing, a base board mounted within the housing for distributing a load source to the switch means, at least one switch support rail mounted on a surface of the base board for mounting and supporting the switches on it, the base board has a modular extension mounting base to accept a modular extension base board to increase the number of switch means placed inside the housing, the mounting base having a box shape rectangular hollow having a top wall, two side walls, a front wall and a rear wall formed by a bottom end wall of the switch support rail.

3. The load center according to claim 2, further characterized by comprising a modular extension base board mounted on the mounting base to extend the length of the base board, the modular extension base board has means for mounting on them from the switches.

4. The load center according to claim 2, characterized in that the mounting base has a trapezoidal shape alignment groove, formed in the upper wall and the side walls thereof, to accept an alignment ramp- 'shaped correspondingly to the link with her.

5. The load center according to claim 2, further characterized in that it comprises a depressed platform which extends between the modular mounting base and a lower edge of the surface of the base board.

. The load center according to claim 2, characterized in that the mounting base has at least one opening for accepting therein a flexible fastening hook, an upper edge of a slot formed in an end wall of the support rail of the vehicle. switch to attach the hook.

7. The load center according to claim 3, characterized in that the modular extension base board has a top surface adapted to receive on it the switch means and means for mounting to the housing.

8. The load center according to claim 4, characterized in that the modular extension base board has switch support rails having a cross-sectional shape of an inverted U, a trapezoidal alignment ramp placed on a wall Inside of its switch support rail, the trapezoidal shape is complementary to the trapezoidal alignment slot of the base board, for mounting the modular extension base board on it.

9. The load center according to claim 6, characterized in that the modular extension base board has at least one flexible fastening hook to secure the modular extension base board to the mounting base.

10. The load center according to claim 3, characterized in that the modular extension base board has a modular extension base to accept a second modular extension base board on it, the mounting base has a rectangular box shape hollow having a top wall, two side walls and a front wall, a rail for the switch holder mounted on a surface of the modular extension base board, the box has a rear wall formed by a bottom end wall of the rail switch support. SUMMARY An electrical load center having a housing with a push screw fastener accessory, a door lock comprising a one piece molded member, having a flexible tongue which pushes the door lock towards the edge of the door articulated keeping a hook engaged in a deflected manner with an edge of the underside of the cutout, a neutral bar having an elongated body portion with a trapezoidal cross-sectional area with the side walls extending downward, with outward inclination having openings for the insertion of electric cables, a neutral connecting rod adapted to be electrically connected to the housing of the load center, a main insulating lug having longitudinally extending compartments in the form of a through and first and second supporting legs for placing on the neutral union bar, a base board that has a surface with poles formed integrally with a lower cut extending around its periphery to secure a component of the load center to the surface by heat stacking, the surface has two integrally formed, spaced-apart wall members extending upwardly from the surface that It forms a barrier between the common connection bars of the load center, the surface having a tongue with a sloping lower edge and a tip extending from a lateral edge of the tongue to be captured by the lances found in the tongue. housing of the load center, the surface having a neutral bar wire guide, comprising a wall extending upwardly from the surface member and having semicircular grooves extending therethrough on an upper surface to receive and guiding a return wire into an opening in the neutral bar, the surface having a base for the modular extension assembly that extends from the lower end wall of a switch support rail to receive a modular extension base board, the mounting base has a confounded, trapezoidal slot for coupling by a correspondingly shaped ramp of the modular extension base board , the modular extension mounting base further has a slot for receiving a flexible attachment hook from the modular extension base board to secure the modular extension base board to the base board.