US3619641A

US3619641A - Auxiliary starter device for air conditioner compressor

Info

Publication number: US3619641A
Application number: US59305A
Authority: US
Inventors: James L Ballard
Original assignee: General Electric Co
Current assignee: Trane US Inc
Priority date: 1970-07-29
Filing date: 1970-07-29
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

This invention is directed to a factory-assembled device which provides field installation personnel with accurate, quickly installed means for adding extra capacitance to the starting circuit of the electric motor for the fluid compressor of an air conditioner.

Description

United States Patent James L. Ballard Tyler, Tex.

July 29, 1970 Nov. 9, 1971 General Electric Company Inventor Appl. No. Filed Patented Assignee AUXILIARY STARTER DEVICE FOR AIR CONDITIONER COMPRESSOR 4 Claims, 4 Drawing Figs.

vs. C] 307/149, 310/71, 318/221 Int. Cl H02j 1/00 Field of Search 310/66, 71;

[56] References Cited UNITED STATES PATENTS 2,181,734 11/1939 Mooney r. 318/221 D 3,350,586 10/1967 Otto 310/71 2,338,515 1/1944 Johns 318/221 A Primary Examiner- Herman J. Hohauser Attorneys-Harry B. O'Donnell, III, Francis H. Boos, Frank L.

Neuhauser, Oscar B. Waddell and Joseph B. Forman ABSTRACT: This invention is directed to a factory-assembled device which provides field installation personnel with accurate, quickly installed means for adding extra capacitance to the starting circuit of the electric motor for the fluid compressor of an air conditioner.

PAIENTEDuov 9 ml 3, 19,641

sum 1 or 2 INVENTOR. J'AME L. BALLARD H \S ATTORNEV PATENTEnunv 9 ISTI SHEET 2 OF 2 H 5 -ATTORNEY AUXILIARY STARTER DEVICE FOR AIR CONDITIONER COMPRESSOR BACKGROUND OF THE INVENTION This invention is related to air conditioners and, more particularly, to an auxiliary starter device for the fluid compressor of a central air conditioner of the so-called split system variety.

Split system air conditioner cooling units generally comprise two basic sections, one of which is referred to as the evaporator section that is mounted within the building to be cooled, and the other of which is referred to as the condensercompressor section that is housed within a cabinet that is mounted outside of the building. The evaporator, condenser and compressor are, of course, fluid-interconnected in a wellknown manner by conduit means.

Because of various reasons, e.g. exposure to the weather, etc., it is usually necessary to replace the condenser-compressor section long before the evaporator section. Many such split-system air conditioner cooling units have been in service in the field for several years and now require replacement of their condenser-compressor sections. However, most of the evaporator sections of these older central air conditioner units differ from modern evaporator sections in that they employed expansion valve means to expand the liquid refrigerant fluid into a gaseous state prior to its entry into the evaporator coil from the condenser-compressor section, rather than the capillary means presently used for this purpose. And, if one at- .-tempts interconnection of a modern replacement condensercompressor section with one of these old evaporator sections, he is almost certain to find that the capacitanceprovided in the starting circuit for the electric motor of the fluid compressor of the modern replacement condenser-compressor section, as supplied from the factory, is then insufficient to permit starting of the replacement compressor.

Heretofore, various schemes have been improvised by field installation personnel in an effort to overcome the aforenoted incompatibility between the modern replacement compressor and the old evaporator section with which it is sought to be coupled. However, these prior art methods have required field rewiring of the replacement compressor motor starting circuit. And, such field rewiring has presented problems, e.g. use of oversized auxiliary capacitors, failure to provide means for disconnecting the auxiliary capacitor from the circuit after the motor starts and is running, etc, which may possibly ruin the compressor motor.

SUMMARY OF THE INVENTION In accordance with the present invention, it has been found that the aforenoted prior art problems can be overcome with a novel, factory-assembled auxiliary starter device which provides field installation personnel with accurate, quickly installed means for adding extra capacitance to the starting circuit of the electric motor for the fluid compressor of an air conditioner. Basically, the present invention comprises: auxiliary capacitor means; auxiliary switching relay means; auxiliary conductor means electrically interconnecting the auxiliary capacitor and switch relay means; base means mounting the auxiliary means and being adapted for ready attachment and detachment to and from cabinet means housing the compressor; and plug means electrically connected to the auxiliary conductor means and readily engageable and disengageable to and from complementary plug means electrically connected to the compressor motorstartingcircuit to quickly electrically connect and disconnect the auxiliary means to and from the compressor motor starting circuit.

BRIEF DESCRIPTION OF THE DRAWING The present invention is illustrated in the accompanying drawings, wherein:

FIG. I is a side elevational view of the condenser-compressor section ofa typical, modern air conditioner cooling unit of the so-called split-system variety incorporating a presently preferred form of the auxiliary starting device of the present invention, with portions of the section cabinet and the compressor housing being broken away and elements normally enclosed by the removable top cover of the cabinet being shown in shadow;

FIG. 2 is an enlarged fragmentary top plan view of the con denser-compressor section illustrated in FIG. 1, with the cabinet being rotated leftward about the vertical axis and the cabinet top cover removed;

FIG. 3 is a still further enlarged fragmentary elevation perspective view of FIG. 2 and illustrates the means provided for the ready attachment and detachment of the auxiliary starting unit to and from the cabinet and for its quick electrical connection and disconnection to and from the compressor motor circuit; and

FIG. 4 is a schematic wiring diagram showing the electric circuit for the auxiliary starting device illustrated in FIGS. 1-3 and its relationship to compressor motor circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing and particularly to FIG. I thereof, there is illustrated a condenser-compressor section 10 of a typical air conditioner cooling unit of the so-called splitsystem variety. The condenser-compressor section 10 comprises a generally rectangular, hollow boxlike cabinet II which includes a lower portion 12 that rests atop a concrete pad 13 which is provided outside the building (not shown) that is to be cooled, and removable cover portion I4. The cabinet lower portion 12 includes four vented, generally vertical side walls 15 and a generally horizontal top wall 16 (partly shown in FIGS. 2 and 3) that is perforated by a large generally circular central opening 17.

As illustrated in FIG. 1, there are housed within the cabinet lower portion l2, among other things, a condenser 18 and compressor 19. The condenser 18 is of a well-known type and comprises a finned tube coiled around the interior of the vented side walls 15 of the cabinet lower portion 12. The compressor 19 is a well-known hermetic type and includes a generally vertically arranged hollow cylindrical housing 20 which contains an electric motor 21 in its upper portion and a reciprocating type pump 22 in its lower portion. The compressor motor 21 includes a stator 23 and a rotor 24 and, as shown schematically in FIG. 4, its stator 23 includes a start winding 23s and a run winding 23r. The compressor pump 22 includes a cylinder block 25 having at least one piston 26 housed therein which is reciprocated by a piston rod 27 that is connected to a crank shaft 28 which is, in turn, connected to the motor rotor 24 in a well-known manner.

The compressor 19 has its discharge outlet 30 located at the lower end of its housing 20 and fluid connected to a conduit 31 which extends outward through an opening 32 provided in one of the sidewalls 15 of the cabinet lower portion 12. The condenser coil 18 has its discharge end connected by another conduit 33 to the compressor inlet 34 provided at the top of the compressor housing 20, while the opposite or inlet end of the condenser coil 18 is fluid connected to yet another conduit 35 which extends outward though the cabinet opening 32 generally parallel to the outer end of the conduit 31 that is fluid connected to the compressor discharge outlet 30. It is to be understood that the parallel outer ends of two

conduits

31 and 35 can be readily fluid connected by well-known means (not shown) to the inlet and outlet ends, respectively, of the evaporator coil (not shown) which is contained within the building (not shown) that is to be cooled.

As further shown in FIG. 1, the cabinet lower portion 12 also supports a fan 36 which circulates outdoor air across the condenser coil 18. The fan 36 includes its own electric motor 37 which is supported generally vertically within the opening 17 in the top wall 16 ofthe cabinet lower portion 12 by spider means or the like (not shown). And, the fan 36 also includes an impeller 38 mounted on a rotary output shaft 39 that extends upwardly from the fan motor 37.

The cabinet cover portion 14 includes a top wall 40 having a screened, generally circular opening 41 and four downwardly extending sidewalls 42. The screened central opening 41 overlies the fan impeller 38 and lower edges of the cover portion sidewalls 42 fit snugly around the upper edges of the four sidewalls of the cabinet lower portion 12 and are attached thereto by removable fastener means, such as sheetmetal screws 43. When installed over the top of the cabinet lower portion, as shown in FIG. 1, the cabinet cover portion 14 encloses the condenser fan impeller 38 and also covers certain electric control means that are provided for the compressor motor 21 in particular accordance with the present invention and will be described in detail hereinafter. As shown in FIG. 1, these compressor motor control means include standard control means 50 mounted on the left front portion of the top wall 16 of the cabinet lower portion 12 and an auxiliary starting device 70 which can be readily attached to the right front portion of the top wall 16 of the cabinet lower portion 12, if required.

As best shown in FIGS. 2-4, the standard compressor motor control means 50 comprises a first or standard capacitor 51,

which is attached to the top wall 16 of the cabinet lower portion 12 by a clamp 52 that is fastened thereto at its opposite ends, and a polarized electric plug 53 which includes a female portion 53f and a removable male portion 53m (FIG. 3). The female portion 53f of the plug 53 has four

socketlike terminals

54, 55, 56 and 57, two of which 55 and 56 are particularly adapted to receive a pair of

pronglike terminals

58 and 59 that are provided on the male portion 53m of the plug 53 and are electrically interconnected by conductor 60.

In accordance with the present invention, it is intended that the condenser-compressor section 10 will be shipped from the factory with the female and

male portions

53f and 53m of the polarized electric plug 53 joined together and having the

pronglike terminals

58 and 59 of the male plug portion 53m inserted into and electrically convected with the

socketlike terminals

55 and 56 ofthe female plug portion 53f. With this factory-shipped, standard arrangement, as shown schematically in FIG. 4, the standard capacitor 51 and the compressor motor stator start winding 23s are connected in electrical series across a pair of main power supply lines L, and L by circuitry which also includes an internal current overload protector device 23;; mounted adjacent the compressor motor stator 23 and a pair of main

power disconnect relays

61 and 62. More specifically, one 61 of the two main

power disconnect relays

61 and 62 has its first terminal 61a electrically connected to the first main power supply line L,, while its second terminal 61b is electrically connected by a conductor 63 to the first terminal 51a of the standard capacitor 51. The second terminal 51b of the standard capacitor 51 is electrically connected to one 55 of the two

socketlike terminals

55 and 56 of the female portion 53fof the polarized plug 53 by a conductor 64, while the other 56 of these two

socketlike terminals

55 and 56 is connected to the first terminal 23st: of the compressor motor stator start winding 23s by a conductor 65. Another conductor 66 electrically connects the second terminal 23sb of the compressor motor stator start winding 23s to the first terminal 23pa of the internal current overload protector device 23p, while yet another conductor 67 electrically connects the second terminal 23pb of the internal current overload protector device 23p to the first terminal 62a of the other one 62 of the pair of main power

supply disconnect relays

61 and 62. Finally, the second terminal 62b of the second disconnect relay 62 is electrically connected to the other main power supply line L,. And, as further shown in FIG. 4, the compressor motor stator run winding 23r is connected in electrical parallel with the series-connected standard capacitor 51 and compressor motor stator start winding 23s by having its first terminal 23m electrically connected by a conductor 68 to the second terminal 611; of the first main power disconnect relay 61 and its second terminal 23rb electrically connected to the second terminal 23sb of the compressor motor stator start winding 23s. It should also be noted that, for a reason that will subsequently be apparent, the socketlike terminal 54 of the female portion 53f of the polarized plug 53 is electrically connected by a conductor 69a to the second terminal 61b of the first power disconnect relay 61 and the socketlike terminal 58 of this female plug portion 53f is electrically connected by another conductor 69b to the first terminal 62a of the second power disconnect relay 62.

With the aforedescribed circuitry and with the female and

male portions

53f and 53m of the polarized electric plug 53 joined together and having the

pronglike terminals

58 and 59 of the male plug portion 53m inserted into and electrically connected with the

socketlike terminals

55 and 56 of the female plug portion 53f, it can be seen that there will be two electric current paths between the main power lines L, and L and through the compressor motor stator 23 when the

disconnect relays

61 and 62 are closed. The first of these two current paths will pass from the first power line L, through the first disconnect relay 61' and then, respectively, through the conductor 63, the standard capacitor 51, the conductor 64, the socketlike terminal 55, the pronglike terminal 58, the conductor 60, the pronglike terminal 59, the socketlike terminal 56, the conductor 65, the start winding 23s, the conductor 66, the internal current overload protector device 23p, the conductor 67, and the second disconnect relay 62 and into the second power supply line L And, of course, the second of these two current paths will pass from the first power supply line L, through the first disconnect relay 61 and then, respectively, through the conductor 68, the stator run winding 23r, the conductor 66, the internal current overload protector device 23p, the conductor 67, the second disconnect relay 62 and into the second main power line L Typically, the sizing of the standard capacitor 51 that is provided in the condenser-compressor unit 10 at the factory will be approximately 10 microfarads per horsepower of the compressor motor 21. Thus, a 30-microfarad capacitor would be utilized for the factory-installed standard capacitor 51 in a condenser-compressor section 10 employing a compressor 19 having a 3-horsepower motor. Or, a 40-microfarad capacitor would be utilized for the standard capacitor 51 in a condensercompressor section a 4-horsepower motor for the compressor motor 21; etc.

It should, of course, be understood that only the standard control group 50 will be installed on the condenser-compressor section 10 at the factory, since this should provide sufficient capacitance to start the compressor motor 21 if the condenser-compressor section 10 is connected in the field to a modern evaporator section. However, as previously noted, it is not infrequently desired to interconnect a modern replacement condenser-compressor section 10 with an old evaporator section. And, for the reasons previously noted, the capacitance provided by the factory-installed standard capacitor 51 will be sufficient to start the compressor motor under these replacement combination conditions.

In the past, various schemes have been improvised by field installation personnel in an effort to overcome the aforenoted incompatibility between a modern replacement condenser compressor section and an old evaporator section with which it is sought to be coupled. However, these prior art methods have required field rewiring of the replacement compressor motor circuit. And, such field rewiring has presented problems, e.g. use of oversized auxiliary capacitors, failure to provide means for disconnecting the auxiliary capacitor from the circuit after the compressor motor starts and is running, etc. which may possibly ruin the compressor motor. However, it has been found that the aforenoted prior art problems can be overcome by the novel factory assembled starter device 70 of the present invention which provides field installation personnel with accurate, quickly installed means for adding extra capacitance to the starting circuit of the electric motor 21 of the fluid compressor 19 of the condenser-compressor section 10 of an air conditioner cooling unit of the so-called splitsystem variety.

As illustrated, the auxiliary starter device 70 of the present invention comprises base means including a base bracket 71 that is perforated with a plurality of fastener receiving openings 72a which are adapted to be readily aligned over complementary fastener receiving openings 72b that are performed at the factory in the right front portion of the top wall 16 of the cabinet lower portion 12 (as seen in FIG. 1) and readily attached to and detached from the top wall 16 by removable fastener means, such as the plural sheetmetal screws 720, which are received in the aligned

openings

72a and 72b. As best shown in FIGS. 2-4, the bracket 71 mounts auxiliary capacitor means including an auxiliary capacitor 73; auxiliary switch relay means 74 including a normally closed switch 74r that can be opened upon actuation of a current level sensitive solenoid 74s; auxiliary current overload protector means including a current overload protector device 75; and auxiliary conductor means for electrically interconnecting the auxiliary capacitor means 73, auxiliary switch plug means including an auxiliary overloadprotector device 75. The auxiliary starter device 70 further comprises auxiliary plug means including an auxiliary male plug 76m that is adapted for quick connection to and disconnection from the female portion 53f of theaforedescribed polarized electric plug 53, upon removal of the male portion 53m of the polarized plug 53 therefrom. This auxiliary plug 76m has four

pronglike terminals

78, 79, 80 and 81, a

first pair

79 and 80 of which are particularly adapted to be respectively received in two 55 and 56 of the socketlike terminals 54-57 of the female portion 53f of the polarized plug 53, and a

second pair

78 and 81 of which are particularly adapted to be respectively received in the other two

socketlike terminals

54 and 57 of the female portion 53f of the polarized plug 53.

In accordance with the present invention, the auxiliary capacitor 73, the auxiliary switch relay means 74 and the auxiliary current overload device 75 are accurately selected at the factory to provide the correct extra starting capacitance for a condenser-compressor section having a compressor motor 21 of a particular horsepower rating, and they are then preattached to the base bracket 71 and prewired to one another and to the auxiliary plug 76m at the factory. To this end, factory personnel selectthe proper sized auxiliary capacitor 73, auxiliary switch means 74 and auxiliary current overload protector device 75 and permanently attach them to the base bracket 71. As illustrated in FIGS. 2 and 3, the auxiliary capacitor 73 is attached to the base bracket 71 by a clamp 730, which is, in turn, permanently secured to the base bracket 71 by welding or other suitable fastening means. And, the auxiliary starting relay means 74 and the auxiliary current overload protector device 75 are respectively attached to mounting

brackets

74c and 75c, which are, in turn, permanently secured to the base bracket 71 by welding or other suitable fastening means.

Then, the following prewiring (best shown in FIG. 4) is performed at the factory. The first terminal 73a of the auxiliary capacitor 73 is electrically connected by a conductor 82 to the pronglike terminal 78 of the auxiliary male plug 76m, while its second terminal 73b is connected by a conductor 83 to the first terminal 74m of the normally closed auxiliary switch relay 74r. The second terminal 74rb of the normally closed auxiliary switch relay 74r is connected by a conductor 84 to the first terminal 74sa of the solenoid 74s of the auxiliary switch relay means 74, while the. second terminal 74sb of the solenoid 74r is connected by a conductor 85 to the pronglike terminal 81 of the auxiliary male plug 76m. The second terminal 74rb of the normally closed auxiliary switch relay 74r is also electrically connected by a conductor 86 to the pronglike terminal 79 ofthe auxiliary male plug 76m. And, the first terminal 74m of the solenoid 74s is connected to the first terminal 75a of the auxiliary current overload protector device 75 by conductor 87, while the second terminal 75b of the auxiliary current overload protector device 75 is connected by a conductor 88 to the pronglike terminal 80 of the auxiliary male plug 76m.

Now, assuming field installation personnel have interconnected a modern condenser-compressor section 10 with an old previously-installed evaporation section (not shown) or that for some other reason the compressor motor 21 of the condenser-compressor unit 10 will not start as shipped from the factory, they may quickly and easily solve this problem by performing the following steps:

l. procuring an auxiliary starter device of the present invention which is sized for use with the particular horsepower rating of the compressor motor 21 that has been factory-installed in the condenser-compressor section 10 (several assorted sized should be carried on their service truck);

2. removing the sheetmetal screws 43 from the cabinet cover 14 and the cover 14 from the cabinet bottom portion 12;

3. aligning the fastener receiving openings 72a in the base bracket 71 of the auxiliary starter device 70 with the fastener receiving openings 72b in the top wall 1670f the cabinet lower portion 12 and then inserting the sheetmetal screws 720 which are provided with the auxiliary device 70;

4. disconnecting the factory-installed male portion 53m from the female portion 53f of the polarized plug 53 of the standard motor control means 50; r

5. connecting the auxiliary male plug 76m of the auxiliary starting device 70 the female portion 53f of the polarized plug 53, with the

pronglike terminals

78, 79, 80 and 81 being respectively inserted into and electrically connected to the

socketlike terminals

54, 55,56 and 57.

Having done this, it can best be seen by reference to FIG. 4

that closure of the two main power disconnects 61 and 62 will initially cause current to flow between the power lines L and L, and through the compressor motor stator start winding 23:

via both the standard capacitor 51 and the auxiliary capacitor 73, which will then be electrically paralleled with one another and connected in electrical series to the compressor motor stator start winding 23s through the auxiliary current overload protector device Thus, during this initial or starting period, the capacitance in the circuit for the compressor motor stator start winding will equal the sum of the capacitive values of the standard capacitor 51 and the auxiliary capacitor 73. And, during this initial period, there will also be a flow of current through the solenoid 74s and, when (usually within 10 seconds after closure of the disconnect switches 61 and 62) the intensity of this current flow becomes sufficient to actuate the solenoid 74s to open the normally closed auxiliary switch relay 74r, the opening of the auxiliary switch relay 74r will then, of course, stop the flow of current through the auxiliary capacitor 73. However, in the event that the auxiliary switch relay means 74 should malfunction and the switch relay 74r remain closed after the compressor motor 21 is started and running, the auxiliary current overload protector device 75 is sized to open thus stop all current flow across the compressor motor stator start winding 23s and thus avoid destruction of the motor 21.

It should be apparent to those skilled in the art that while there has been described what, at present, is considered to be a presently preferred embodiment of this invention in accordance with the disclosed apparatus without actually departing from the true spirit and scope of this invention. For example, the auxiliary start device 70 of the present invention obviously could also be used to provide extra capacitance in the starting circuit of the compressor motor for an air conditioner of the heat pump variety. It is, therefore, intended that the appended claims shall cover such modifications and applications that do not depart from the true spirit and scope of the present invention.

What is claimed is:

I. An auxiliary starter device for quickly and accurately providing extra capacitance in the starting circuit of the electric motor for the fluid compressor of an air conditioner comprising:

a. auxiliary capacitor means;

patent statutes, changes may be made to theb. auxiliary switching relay means;

0. auxiliary conductor means electrically interconnecting said auxiliary capacitor and switch relay means;

d. base means mounting said auxiliary means and being adapted for ready attachment and detachment to and from cabinet means housing the compressor; and

e. plug means electrically connected to said auxiliary conductor means and being readily engageable and disengageable to and from complementary plug means electrically connected to the compressor motor starting circuit to quickly electrically connect and disconnect said auxiliary means to and from the compressor motor starting circuit.

Claims

1. An auxiliary starter device for quickly and accurately providing extra capacitance in the starting circuit of the electric motor for the fluid compressor of an air conditioner comprising: a. auxiliary capacitor means; b. auxiliary switching relay means; c. auxiliary conductor means electrically interconnecting said auxiliary capacitor and switch relay means; d. base means mounting said auxiliary means and being adapted for ready attachment and detachment to and from cabinet means housing the compressor; and e. plug means electrically connected to said auxiliary conductor means and being readily engageable and disengageable to and from complementary plug means electrically connected to the compressor motor starting circuit to quickly electrically connect and disconnect said auxiliary means to and from the compressor motor starting circuit.

2. The invention of claim 1, further including auxiliary current overload protector means mounted on said base means and electrically interconnected with said auxiliary capacitor and switch relay means by said auxiliary conductor means.

3. The invention of claim 2, further including fastening receiving means provided on said base means and being readily alignable with complementary fastener receiving means provided on the cabinet means.

4. The invention of claim 1, further including fastener receiving means provided on said base means and being readily alignable with complementary fastener receiving means provided on the cabinet means.