CA1206245A

CA1206245A - Starting and thermal protection relays terminal box group for hermetic motorcompressor

Info

Publication number: CA1206245A
Application number: CA000424243A
Authority: CA
Inventors: Alfredo Bar
Original assignee: Necchi SpA
Current assignee: Necchi SpA
Priority date: 1982-06-11
Filing date: 1983-03-23
Publication date: 1986-06-17
Also published as: IT8242911A1; GB8310788D0; IT8242911A0; GB2122430B; GB2122430A; SE8303313D0; DE3320391A1; SE8303313L; IT1159282B; SE456300B

Abstract

Abstract:
The invention relates to a terminal box for the motor-compressor of a refrigeration device. The terminal box contains internal divisions for the starting relay and the thermal protection relay employed with such refrigeration devices. The internal division are separated by walls that thermally isolate the two relays. The electrical terminals are located on a wall of the box that, when installed on the motorcompressor located inside a suitable cabinet, face the service operator for ease of attachment and removal of the electrical connectors. The box is suitably shaped that it does not project outwardly by a significant distance from the motorcompressor when attached thereto. The terminal box conveniently houses all of the external elements of the motorcompressor in a space-saving manner while allowing for easy access.

Description

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Startin~ and thermal protection relays terminal box group for hermetic motorcom~ressor _ _______ _ __ ___ _ The present invention relates to a box for the starting and thermal protection relays and terminals of a sealed motorcompressor.
In West German Patent Applicat:ion No. P 32 30 584.2 of the present applicant publishec3 on March 10, 1983, a starting relay-terminal box of the PTCR type is shown, placed on an external wal.l of the shell of a motorcom-pressor and having such a shape as to have a res~ricted height relative to the external shell surface, and to have the electrical connection terminals placed to face a person situated beh.ind a cooling cabinet in which the motorcompressor is located.
An object of the present invention is to provide a box additionally containing a thermal protection relay as well as the starting relay, the relays being close enough to make an integral group of restr.icted dimensions, inside which the said relays do not influence one another ther-mally, while mainta.ining unchanged the advantages and features of the solution in the application referred to above.

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According to the invention there is provided in a cooling device comprising an outer cabinet having an access opening and containing a hermetically sealed motorcompressor having an outer shell, a starting relay, a thermal protection relay and electrical termin~ls, the improvement which comprises a box having internal com-partments thermally separated by walls for housing the starting and thermal protection relays and having said terminals located on an external wall of the box, said box being attached to the shell of the motorcompressor with said terminals facing said access opening, and the box being shaped such that its dimension perpendicular to the adjacent surface of the shell is considerably less than its larger dimension parallel to the adjacent surface of the shell.
Further advantages and characteristics will become apparent from the following description of a preferred embodiment of the invention and from the annexed drawings, in which:
Fig. 1 shows a view of the relay~s-terminal box container app]ied to a motorcompres~sor shell, Fig. 2 shows a view of the relays-terminal box container, Fig. 3 is a sectional view along line 3-3 of the container shown i~ Fig. 2, Fig. 4 shows the electrical layout, and Figs. 5 and 6 are views of the container shown in Figs. 2 and 3 according to an alternative embodiment.
With reference to Fig. 1, numeral 10 indicates the shell of a sealed compressor held in place by means o a plate 12 connected to the shell and to a resilient support 14 on the bottom surface 16 of a compartment 18 located at the rear of a lower portion 20 of a cooling cabinet, A starting and thermal protection relays-terminal box 22 is fixed laterally to the shell~ the box being closed at the front portion by a cover 24. The box is connected to the main network by means of cables 26.

~20~24 2a -With reference to Fig. 4, the electrical feed circuit of the motorcompressor comprises a thermal protection relay 28 provided with a bimetallic blade 30 and, according to the type used, a heating resistance 32~ the function of which i5 described below.
The relay 28 is connected in series with two windings of an electrical motor 34, more precisely the working winding 36 and the starting winding 38.
A starting relay 40 of the PTCR type (positive temperature coefficient relay) is provided in series with the starting winding 38.

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With reference to Fig. 2, the relays-terminal box 22 is formed by an outer container 43 of plastic material inside which the starting relay 40 and the thermal protec-tion relay 28 are arranged in suitable housings separated rom each other by walls, as shown. On the outer lateral wall 42, terminal box 44 is provided, which comprises screw terminals 46 and slide-on type connectors 48 for connection to the circuit of Fig. 4.
As shown in ~ig. 3 and Fig. 1~ the space occupied by the relays-terminal box, taken along a line perpendicular to the vertical wall of the shell 1~, measured by H in Fig. 1, is very restricted, i.e. the dimension of the compressor-relays-terminal box is very thin in the transverse direction. A further advantage derives, as already mentioned, by having the term;nal box arranged on an external wall of the container, with the terminals facing the operator, behind cover 24 of Fig. 1, thus making it easier for the operator to connect the mains network cables to the terminal box and to service it.
In Figs. 5 and 6 r another solution i5 shown, in which another type of thermal protection reLay 50 is employed which is different from relay 28 of Fig. 2. In Figs~ S
and 6, the remaining components are indicated with the sam~ numerals used in Figs. 2 and 3. The thermal protec-tor indicated by numeral 50 in Fig. 6 is of the type commonly used in the motorcompressor field, but on the contrary the one used and indicated by numeral 28 in the embodiment of Fig. 2, is produced by the 5ylvania Company and sold on the market with the designation "glass case protector". It is provided with a heater 32 having the task of increasing the amperometric sensitivity of the protector consequently causing an increase of the times of remake.

Claims

Claims:

1. In a cooling device comprising an outer cabinet having an access opening and containing a hermetically sealed motorcompressor having an outer shell, a starting relay, a thermal protection relay and electrical terminals, the improvement which comprises a box having internal com-partments thermally separated by walls for housing the starting and thermal protection relays and having said terminals located on an external wall of the box, said box being attached to the shell of the motorcompressor with said terminals facing said access opening, and the box being shaped such that its dimension perpendicular to the adjacent surface of the shell is considerably less than its larger dimension parallel to the adjacent surface of the shell.