CN112448206A

CN112448206A - Adapter system for connecting a power source to a load

Info

Publication number: CN112448206A
Application number: CN202010771806.6A
Authority: CN
Inventors: N.A.卡内基; B.F.弗莱格尔; J.坎普施罗尔; C.弗莱格尔
Original assignee: Reliance Controls Corp
Current assignee: Reliance Controls Corp
Priority date: 2019-08-28
Filing date: 2020-08-04
Publication date: 2021-03-05

Abstract

The present inventors have recognized that locating a cable adapter that may be needed in an electrical system, such as between a generator and an electrical input, may be greatly facilitated by applying visually distinctive indicators, such as colors, molded patterns or shaped identifiers, shaped protrusions, etc., at the end of each cable adapter, which correspond to various types of electrical/mechanical standards or connections. This, in turn, may allow for rapid deployment of such cable adapters in a system, including from a kit.

Description

Adapter system for connecting a power source to a load

Technical Field

The present invention relates to the field of power transmission, and more particularly, to a system and method for adapting power between a power source and a load of a power transmission.

Background

The need for backup and sometimes portable power is becoming more prevalent. Unfortunately, electrical products often lack standardization in electrical connections. The power source and load may utilize many different types of electrical connections, such as various types of National Electrical Manufacturers Association (NEMA) connectors, including NEMA 14-50, NEMA Travel Trailer (TT)30, NEMA L14-30, NEMA L5-30, NEMA L14-20, NEMA L5-20, NEMA 5-15, and so forth. As a result, female receptacles of one type are often incompatible with male cable connectors or plugs of another type.

Thus, when connecting a given power source or an extension of a given power source to an electrical load, the probability of having the correct type of power cord available for the power source and the load may be low. Furthermore, even with the correct power cord, it is difficult to find such a power cord among many power cords that look similar but not identical. There is a need for a system for efficiently adapting a power source to an electrical load having different types of electrical connections.

Disclosure of Invention

The present inventors have recognized that locating a cable adapter that may be needed in an electrical system, such as between a generator and an electrical input, may be greatly facilitated by applying visually distinctive indicators, such as colors, molded patterns or shape identifiers, shaped protrusions, etc., at the end of each cable adapter, which correspond to various types of electrical/mechanical standards or connections. This, in turn, may allow for rapid deployment of such cable adapters in a system, including deployment from a kit.

Specifically, one aspect of the present invention may provide an electrical adapter system comprising: each end portion includes a male plug or a female receptacle, each end portion being defined by a given one of a plurality of types, wherein the male plug and the female receptacle of the same type are plug-compatible with each other, the male plug and the female receptacle of the different type are incompatible with each other, each type corresponding to a distinct indicator, and each end portion having a distinct indicator indicating the given type, wherein the first and second end portions of the first power cord and the first end portion of the second power cord are of the same type having the same distinct indicator, and the second end portion of the second power cord is of a different type having a different distinct indicator, and wherein the second end portion of the first power cord is plug-compatible with the first end portion of the second power cord of the same type for transmitting power from the first end portion of the first power cord to the second end portion of the second power cord.

The present invention also provides an adapter system for efficiently adapting a power source, typically having an extension cord, to an electrical load by providing a set of cord adapters, wherein each cord adapter has a first end having a first pattern, color or sensory indicia for adapting to one type of electrical connection and a second end having a second pattern, color or sensory indicia, different from the first pattern, color or sensory indicia, for adapting to another type of electrical connection. This may allow a power cord adapter to be connected to such extension cord at the end having the common indicia for adapting a given power source to a load. Such differences in indicia corresponding to differences in the types of electrical connections may allow an observer to visually and quickly select a cord adapter suitable for use with an extension cord, including selecting from a larger group of cord adapters, for adapting between a particular power source and electrical load, each requiring a different type of electrical connection.

Other aspects, objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

Drawings

For the purpose of illustration, certain embodiments of the invention are shown in the drawings. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instrumentalities shown. Like numbers refer to like elements throughout. In the drawings:

FIG. 1 illustrates an exemplary prior art power cord adapter for adapting between different types of electrical connections;

FIGS. 2A and 2B illustrate an exemplary kit or kit having different adapter power cords for adapting differently between different types of electrical connections according to a pattern, color, or perceptual marking (distinctive indicia), according to an aspect of the present invention;

FIG. 3 illustrates an exemplary system including a power cord in accordance with an aspect of the present invention;

FIG. 4 illustrates exemplary first and second power lines for use in the system of FIG. 3;

FIG. 5 illustrates an isometric view of an end portion of an exemplary power cord having a female receptacle and being of a first type, according to an aspect of the present invention;

FIG. 6 illustrates an isometric view of an end portion of another exemplary power cord having a male plug and being of a first type such that the male plug is compatible with the female receptacle of FIG. 5, in accordance with an aspect of the present invention;

FIG. 7 illustrates an exemplary system including multiple power cords of different types, in accordance with an aspect of the present invention; and

fig. 8 illustrates an exemplary system including a power cord according to another aspect of the present invention.

While the invention is described herein in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.

Detailed Description

Referring now to the drawings, and initially to FIG. 1, a power cord adapter 10 for adapting between different types of electrical connections is well known. However, there are countless possible adapter combinations using different power cord adapters 10, which makes it difficult for a retailer to stock all possible combinations. Furthermore, the task of selecting an appropriate power cord adapter 10 to connect different types of electrical connections may be daunting, as the configuration of each connector is not always apparent to an observer.

The present invention thus provides an adapter system for more efficiently adapting a power supply to an electrical load by providing one or more power line adapters, wherein each power line adapter has a first end portion having a first pattern, color or perceptual indicia (distinctive mark) representative of one type of electrical connection and a second end portion having a second pattern, color or perceptual indicia representative of another type of electrical connection, hereinafter simply referred to as "distinctive mark" or "indicia". Such differences in indicia corresponding to differences in the types of electrical connections may allow an observer to visually and quickly select a power cord adapter, including selecting from a larger group of power cord adapters, for adapting between a particular connection associated with the power source and a particular connection associated with the electrical load, each connection requiring a different type of electrical connector.

Referring now to fig. 2A and 2B, an exemplary electrical adapter system 12 is provided in accordance with the present invention. The system 12 may include one or more electrical adapter cords 14 (shown as fourteen adapter cords 14a-14 n). Each adapter power cord 14 may have a first end 16 and a second end 18, the first end 16 having a male plug configured for a first electrical connection and the second end 18 having a female receptacle configured for a second electrical connection. As an adapter, for each power cord, a male plug of a first type is generally incompatible with a female receptacle of a second type, such that the female receptacle cannot receive the male plug.

For each adapter cord 14, the first end 16 may include a first indicia representative of its configuration to accommodate a first type of connection and the second end 18 may include a second indicia, different from the first indicia, representative of its configuration to accommodate a second type of connection. The various numbers are indicated in the figures by reference numerals 26a-26h and are shown in various hatchings accordingly. For example, the first and second different colors may be selected from: orange (indicated by 26 a); gray (indicated by 26 b); transparent (represented by 26 c); red (represented by 26 d); dark green (denoted by 26 e); purple (represented by 26 f); blue (represented by 26 g); and a light green color (indicated by 26 h). The power cable section 19 may include a plurality of wires insulated from each other connecting the first and

second end portions

16 and 18, respectively, and may include a third marking further different from the first and second colors or patterns. For example, the power cable section 19 may be black. In this manner, each adapter cord 14 includes a male end having one of the colors described above and a female end having one of the different colors described above.

In one aspect, a plurality of different adapter power cords 14, each having a unique end configuration for adapting to different types of connections in different ways, may be provided in a kit or kit 20, such as the fourteen unique adapter power cords 14a-14n shown in FIGS. 2A and 2B. For each adapter cord 14, the first end 16 may be configured for one type of connection and the second end 18 may be configured for another type of connection, the two types of connections being incompatible with each other such that they cannot be connected together. For example, a first adapter power cord 14a may have a first end 16 and a second end 18, the first end 16 configured with a male plug, wherein the end has a first indicia 26a (orange) configured for one type of connection, such as national electrical manufacturers association NEMA 14-50; the second end 18 is configured with a female receptacle wherein the end has a second marking 26b (grey) configured for another type of connection, such as NEMA TT 30, the ends being incompatible with each other.

Further, the ends of the adapter power cord 14 having the same type of connection, whether configured as a male plug or a female receptacle, may also have the same designation. For example, a first adapter power cord 14a may have a first end 16 configured with a male plug, wherein the end has a first indicia 26a (orange) configured for one type of connection, such as NEMA 14-50; while the third adapter power cord 14c may have a second end 18 configured with a female receptacle, which end also has the same first indicia 26a (orange) configured for the same type of connection, also NEMA 14-50. As a result, the different types of adapter cords 14 in the kit or set 20 can be quickly, visually, and easily distinguished by an observer based on color or pattern, thereby allowing the observer to quickly select the appropriate adapter cord 14 to adapt a given power source to a given electrical load.

In one aspect, the adapter power cord 14 in the kit or set 20 may have various types of NEMA connectors at each end, and corresponding colors or patterns that match these types. For example, the adapter power cord 14 has a male or female end configured for NEMA 14-50, which may be orange; the adapter power cord 14 having a male or female end configured for NEMA TT 30 may have a gray end; the adapter power cord 14 having a male or female end configured for NEMA L14-30 may have a transparent end; the adapter power cord 14 having a male or female end configured for NEMA L5-30 may have a red end; the adapter power cord 14 having either a male or female end configured for NEMA L14-20 may have a dark green end; the adapter power cord 14 having a male or female end configured for NEMA L5-20 may have a purple end; the adapter power cord 14 having a male or female end configured for NEMA 5-20 may have a blue end; and the adapter power cord 14 having a male or female end configured for NEMA 5-15 may have a light green end. Thus, the type of connection at the end of the adapter power cord 14 may vary, for example, in terms of connection direction, length, pinout, voltage rating, etc., according to the NEMA standard or other standards.

As an alternative to all adapter cords 14 being available in a single kit 20, it is also contemplated that in practice, each adapter cord 14a-14h may be available individually, such as in a retail establishment or a catalog or online purchase environment. In this manner, a user may identify the desired connection at the power source and the load and then quickly and easily visually identify and purchase only the adapter cord 14, wherein 1) the connector at one end is configured to engage the power source, typically a socket, via an extension cord, and 2) the connector at the other end is configured to engage the load, typically a plug.

Referring now to fig. 3, an exemplary system 50 may include various power cords provided in accordance with an aspect of the present invention. At one end of the system 50, a generator 52 (which may be a gasoline generator) may be configured to provide power to a load through an electrical output 54 (plug or socket). The first power cord 60, having first and second ends 62a and 62b, respectively, may be configured to plug into the generator 52 and distribute power over a distance. Thus, the first power line 60 may be an "extension line". At the other end of the system 50, the power input 74 may include a junction box configured to provide power to various loads of the circuit 78, and the power input 74 may be configured to receive power at an electrical input 76 (plug or receptacle). However, in the system 50, the electrical output 54 and the electrical input 76 may be of different types that are incompatible with each other. Furthermore, the first power line 60, while having the same type at the first end 62a as the electrical output 54, typically does not match the desired type of electrical input 76 at the second end 62b, thereby causing continuity issues.

There are many different "types" or standards of electrical and mechanical connections. Types include male plugs and female sockets. For the same type, the male plug and female receptacle are electrically and mechanically compatible with each other, such that the male plug and female receptacle are electrically compatible and operable with each other. For different types, the male plug and the female receptacle may not be electrically and/or mechanically compatible with each other, such that the male plug and the female receptacle may not be plug compatible and/or electrically operable with each other. Types may include, for example, National Electrical Manufacturers Association (NEMA)14-50, NEMA Travel Trailer (TT)30, NEMA L14-30, NEMA L5-30, NEMA L14-20, NEMA L5-20, NEMA 5-20, and NEMA 5-15.

To address the above-described continuity issue in the system 50, the second power cord 70 has a first end 72a and a second end 72b, the second power cord 70 being configured with the correct type for insertion of the first power cord 60 and the electrical input 76 at opposite ends. In particular, the first end 72a of the second power cord 70 may be of the same type as the second end 62b of the first power cord 60. Further, the second end 72b of the second power line 70 may be of the same type as the electrical input 76. As a result, the second power line 70 may complete a connection for transmitting power from the generator 52 to the power input 74 through the first and

second power lines

60 and 70, respectively.

According to the invention, each "type" has a corresponding pattern, color or perceptual marking or "distinctive mark" specific to that type. This allows each end of each power cord to be marked with a distinct indicator indicating the given type of end. Such differences in distinguishing indicia corresponding to differences in the types of electrical connections may allow an observer to visually and quickly select a power cord adapter, including from a larger group of power cord adapters, for adapting between particular power sources and loads requiring different types of electrical connections. For example, in the system 50, the observer need not know the actual type of electrical output 54, first power line 60, or electrical input 76 that is required. Instead, the observer need only recognize the distinctive indicators (distinctive indicators) of the second end portion 62b of the first power supply line 60 and the electrical input portion 76, and select the second power supply line 70 based on the end portions correspondingly matching such distinctive indicators.

The distinctive indicator may include a pattern, color, molded pattern or shaped identifier, shaped protrusion, or other sensory indicia, including visually distinct but identically colored indicia, as described herein. In one aspect, the distinguishing indicator can include colors including orange, gray, transparent, red, dark green, purple, blue, and aqua green. For example, one end of a male plug or female receptacle compatible with NEMA 14-50 types may each have an orange distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA TT 30 types may each have a gray distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA L14-30 types may each have a transparent distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA L5-30 types may each have a red distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA L14-20 types may each have a dark green distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA L5-20 types may each have a purple distinguishing indicator, one end of a male plug or female receptacle compatible with NEMA 5-20 types may each have a blue distinguishing indicator, and an end having a male plug or female receptacle compatible with NEMA 5-15 types may each have a distinctive indicator of a light green color.

Furthermore, providing an indistinguishable indicator, e.g., black, between opposite ends of each power cord may provide further advantages. The indistinguishable indications between the ends, for example along the insulated wire portions, may make the distinct indications at each end more apparent to an observer. Further, the non-distinctive indicator between the ends may provide a common standard between a plurality of power cords in the kit, each power cord having an end with a different distinctive indicator.

Referring additionally to fig. 4, in accordance with one aspect of the present invention, exemplary first and

second power lines

60 and 70, respectively, are provided that are plugged and connected together. In this example, the power receptacle 54 may be a NEMA L14-30 type. Thus, first and second ends 62a and 62b of first power line 60 may correspond to NEMA L14-30 types, respectively, each having a distinct indicator of a transparent end. However, the power input 74 may be a NEMA L5-30 type corresponding to a red differentiation indicator. In order to quickly adapt the generator 52 to the power input 74, a viewer can easily observe the distinctive indicators of the transparent (shown with small squares) and red (shown with small stars) ends and can locate the second power cord 70 with such distinctive indicators at these ends. That is, the observer can easily locate the second power cord 70 having a transparent distinguishing indicator portion at the first end 72a that matches the second end 62b of the first power cord 60 and a red distinguishing indicator portion at the second end 72b that matches the power input 74. Thus, the second power cord 70 may be an "adaptor cord"

Referring now to fig. 5 and 6, isometric views of exemplary ends of the same type of power cord are provided, according to an aspect of the present invention. In fig. 5, the power cord 80 may include an end 82, the end 82 including a female receptacle of a first type, such as NEMA L5-20. The first type may be indicated by a corresponding distinctive indicator 84 on the housing of the female receptacle, such as a purple end shown by a small circle. The female receptacle may include one or more ports 86 for receiving pins from the same type of male plug. With additional reference to fig. 6, the power cord 90 may include an end 92, the end 92 including a male plug, also of the first type, such as NEMA L5-20. The first type may also be indicated by a corresponding differential indicator 84 (the same differential indicator as end 82) on the housing of the male plug, or may be a purple end shown by a small circle. The male plug may include one or more prongs 94 or tabs for electrical and mechanical engagement with the female receptacle at end 82.

Referring now to fig. 7, in accordance with one aspect of the present invention, a different type of power cord kit 100 is provided. The kit 100 may include a first power cord 102 having a first type of end 104, such as NEMA L5-20, including a male plug. The end 104 may include a first distinctive indicator 106 (purple end represented by small circles) for identifying a first type. The kit 100 may also include a second power cord 112 having a first type of end 114, also NEMA L5-20, including a female receptacle. The end portion 114 may also include a first distinguishing indicator 106 (purple color indicated by small circles) for identifying a first type. The male plug at end 104 and the female receptacle at end 114 are of the same type indicated by differential indicator 106, confirming that these ends are electrically and mechanically compatible with each other.

The kit 100 may also include a third power cord 122 having a second type of end 124, such as NEMA 5-20, including a male plug. The end 124 may include a second distinctive indicator 126 (blue end shown by triangle) for identifying a second type. The kit 100 may also include a fourth power cord 132 having a second type of end 134, also NEMA 5-20, including a female receptacle. The end 134 may also include a second distinctive indicator 126 (blue end shown by triangle) for identifying a second type. The male plug at end 124 and the female receptacle at end 134 are of the same type indicated by differential indicator 126, confirming that these ends are electrically and mechanically compatible with each other.

In addition, the kit 100 may also include a fifth power cord 142 having a third type of end 144, such as NEMA 5-15, including a male plug. The end 144 may include a third zone indicator 146 (a light green end shown by a small plus sign) for identifying a third type. The kit 100 may also include a sixth power cord 152 having a third type of end 154, also NEMA 5-15, including a female receptacle. The tip 154 may also include a third zone indicator 146 (a light green tip shown by a small plus sign) for identifying a third type. The male plug at end 144 and the female receptacle at end 154 are of the same type indicated by differential indicator 146, confirming that these ends are electrically and mechanically compatible with each other. It will be appreciated that many power cords may be similarly provided in the kit 100, with the use of a distinctive indicator, typically comprising a color, corresponding to different combinations of criteria at the ends of the power cords available in the kit.

Referring now to fig. 8, according to another aspect of the present invention, an exemplary system 150 may include various power cords provided according to an aspect of the present invention. At one end of the system 150, a generator 152, which may be a gasoline generator, may be configured to provide power to a load through an electrical output 154 (plug or socket). The first power cord 160, having first and

second ends

162a and 162b, respectively, may, in turn, be configured to plug into the generator 152 and distribute power to power receiving units located some distance away. Specifically, the first end 162a of the first power cord 160 may be configured to plug into the generator 152, while the second end 162b of the first power cord 160 may be configured to plug into an electrical input 176 (plug or receptacle) of the first power input 174, the first power input 174 may include a junction box configured to provide power to various loads of the first electrical circuit 178 (e.g., conventional household loads). Thus, the first power cord 160 may be a "generator extension cord".

However, it may sometimes be desirable to instead connect the power from the generator 152 to a different type of electrical input that is incompatible with the first power cord 160, such as the electrical input 276 (plug or receptacle) of the second power input 274, which may include a different standard junction box configured to provide power, such as three-phase power, to various loads of the second circuit 278. This may occur, for example, during a power outage. However, this leads to continuity problems because the second end 162b of the first power line 160 does not match the type of electrical input 276 required.

To address this continuity issue in the system 150, the user need only obtain a second power cord 170, the second power cord 170 having a first end 172a and a second end 172b, respectively, the second power cord 170 being configured with the correct type for inserting the first power cord 160 and the second electrical input 276 at opposite ends. In particular, the first end 172a of the second power line 170 may be of the same type as the second end 162b of the first power line 160. Further, the second end 172b of the second power cord 170 may be of the same type as the second electrical input 276. As a result, the second power line 170 may complete a connection for transmitting power from the generator 152 to the second power input 274 through the first and

second power lines

160 and 170, respectively. Advantageously, the owner need not know the actual type of electrical receptacle 154, first power cord 160, or second electrical input 276 that is required. Instead, the owner need only identify the distinctive indicators (distinctive indicators) of the second end 162b of the first power cord 160 and the electrical input 276, and select the second power cord 170 based on the end that matches such distinctive indicators accordingly. Thus, the second power line 170 may be an "adaptation line".

It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth herein. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It is also to be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.

Cross Reference to Related Applications

This application is a continuation-in-part application, entitled "Adapter System for Connecting Electrical Sources to Loads", filed on 6.1.2020, which claims priority from U.S. provisional patent application No.62/892,638, filed on 28.8.2019, entitled "Adapter System for Connecting Electrical Sources to Loads", each of which is incorporated herein by reference.

Claims

1. An electrical adapter system comprising:

first and second power cords, each power cord having first and second ends, each end including a male plug or female receptacle, each end being defined by a given one of a plurality of types, wherein male plugs and female receptacles of the same type are plug-compatible with one another, male plugs and female receptacles of different types are incompatible with one another, a distinct indicator is associated with each type, and each end has a distinct indicator indicating the given type,

wherein the first and second ends of the first power line and the first end of the second power line are of the same type with the same distinctive indicator, and the second end of the second power line is of a different type with a different distinctive indicator, and

wherein the second end of the first power line is plug compatible with the first end of a second power line of the same type for transferring power from the first end of the first power line to the second end of the second power line.

2. The electrical adapter system of claim 1, wherein the first and second ends of the first power cord are incompatible with each other.

3. The electrical adapter system of claim 2, wherein the first and second ends of the first power cord are incompatible with each other because each end includes a male plug.

4. The electrical adapter system of claim 2, wherein the first and second ends of the first power cord are incompatible with each other because each end includes a female receptacle.

5. The electrical adapter system of claim 1, wherein the distinguishing indicator comprises a color selected from orange, gray, transparent, red, dark green, purple, blue, and light green.

6. The electrical adapter system of claim 1, wherein each type differs in connection direction, which prevents plug compatibility of a male plug with a different type of female receptacle.

7. The electrical adapter system of claim 1, wherein each type differs in voltage rating.

8. The electrical adapter system of claim 1, wherein the plurality of types includes national electrical manufacturers association NEMA 14-50, NEMA Travel Trailer (TT)30, NEMA L14-30, NEMA L5-30, NEMA L14-20, NEMA L5-20, NEMA 5-20, and NEMA 5-15.

9. The electrical adapter system of claim 1, wherein each power cord comprises a plurality of wires insulated from one another.

10. A method for adapting power in an electrical system, comprising:

providing first and second power cords, each power cord having first and second ends, each end including a male plug or female receptacle, each end being defined by a given one of a plurality of types, wherein male plugs and female receptacles of the same type are plug-compatible with one another, different types of male plugs and female receptacles are incompatible with one another, a distinct indicator is associated with each type, and each end has a distinct indicator indicating the given type,

11. The method of claim 10, further comprising providing the first and second ends of the first power cord such that they are incompatible with each other.

12. The method of claim 11, further comprising providing the first and second ends of the first power cord such that each end consists of a male plug.

13. The method of claim 11, further comprising providing the first and second ends of the first power cord such that each end consists of a female receptacle.

14. The method of claim 10, further comprising the distinguishing indicator comprising a color selected from the group consisting of orange, gray, transparent, red, dark green, purple, blue, and light green.

15. The method of claim 10, further comprising each type differing in connection direction, which prevents plug compatibility of a male plug with a different type of female receptacle.

16. The method of claim 10, further comprising each type differing in voltage rating.

17. The method of claim 10, further comprising the plurality of types including national electrical manufacturers association NEMA 14-50, NEMA Travel Trailer (TT)30, NEMA L14-30, NEMA L5-30, NEMA L14-20, NEMA L5-20, NEMA 5-20, and NEMA 5-15.

18. The method of claim 10, further comprising each power cord comprising a plurality of wires insulated from one another.