Friedrich WY12A33G-A, WY09A33F-A, WE15A33B, WE12A33E-B, WE09A33E-C Service Manual

...
Service & P arts Ma nu al
®
Thru-the-Wall
WS07A10B WS10A10B WS12A10E-B WS12A10E-C WS12A30E-B WS15A30B WE09A33E-C WE12A33E-B WE15A33B WY09A33F-A WY12A33G-A
WM0100 (5-03)
TABLE OF CONTENTS
GENERAL
Friedrich WallMaster Model Code........................................................................................................ 4
Application and Sizing ......................................................................................................................... 4
Instructions For Using Cooling Load Estimate Form............................................................................ 5
Cooling Load Estimate Form ............................................................................................................... 6
Heat Load Form .................................................................................................................................. 7
Heating Load From Friedrich Unit Heat Pumps ................................................................................... 8
SPECIFICATIONS/PERFORMANCE DATA
Specifications "WS" Models ................................................................................................................ 9
P erformance Data "WS" Models.......................................................................................................... 9
Specifications "WE" and "WY" Models ................................................................................................ 10
Pe rformance Data Heating "WE" Models............................................................................................. 11
Pe rformance Data Heating "WY" Models............................................................................................. 12
COMPONENTS OPERATION/TESTING
Compressors....................................................................................................................................... 13
Thermal Ov erload (External) ............................................................................................................... 13
Thermal Overload (Internal) ................................................................................................................ 14
Fan Motor............................................................................................................................................ 14
System Control Switch ("WS" Models) ................................................................................................ 15
System Control Switch ("WE" & "WY" Models).................................................................................... 15
Run, Capacitor .................................................................................................................................... 16
Thermostat ("WS" Models).................................................................................................................. 17
Thermostat ("WE" & "WY" Models) ..................................................................................................... 17
Thermostat Adjustment ....................................................................................................................... 18
Heating Element ("WE" & "WY" Models) ............................................................................................. 18
Defrost Control ("WY" Models Only).................................................................................................... 18
Defrost Bulb Location (All "WY" Models) ............................................................................................. 19
Solenoid Coil ("WY" Models Only)....................................................................................................... 19
Check V alv e......................................................................................................................................... 19
Drain Pa n Valv e................................................................................................................................... 20
Rev ersing V alv e ("WY" Models Only) .................................................................................................. 20
Sealed Refrigeration System Repairs.................................................................................................. 21
Hermetic Component Replacement ................................................................................................. ... 21
Special Procedure in the case of Motor Compressor Burn-Out ........................................................... 22
Rotary Compressor Special Troubleshooting & Service ...................................................................... 22
Refrigerant Charge.............................................................................................................................. 22
PAGE
TABLE OF CONTENTS (Cont.)
TROUBLESHOOTING
T roub leshooting T ouch Test Chart........................................................................................................ 23
Troubleshooting (Cooling).................................................................................................................... 24
Troubleshooting (Heating) ................................................................................................................... 28
T roub leshooting (Cooling/Electric) ............................................................................................. .......... 30
WIRING DIAGRAMS
WS07A10E-D ...................................................................................................................................... 34
WS09A10 ............................................................................................................................................ 34
WS12A10 ............................................................................................................................................ 34
WS09A30 ............................................................................................................................................ 34
WS12A30 ............................................................................................................................................ 34
WS13A30 ............................................................................................................................................ 34
WE09A33 ............................................................................................................................................ 35
WE12A33 ............................................................................................................................................ 35
WE13A33 ............................................................................................................................................ 35
WY09A33 ............................................................................................................................................ 36
WY12A33 ............................................................................................................................................ 36
PAGE
PARTS LIST
"WS" Series Parts List......................................................................................................................... 38
"WE" & "WY" Series Parts List ............................................................................................................ 44
WallMaster Sleeve Parts List............................................................................................................... 47
4
FRIEDRICH ROOM MODEL NUMBER CODE
1st DIGIT - FUNCTION
W = Thru-The-Wall, W allMaster Series
2nd DIGIT - TYPE
S = Straight Cool E = Electric Heat Y = Heat Pump
3rd & 4th DIGITS - APPROXIMATE BTU/HR (Cooling)
Heating BTU/HR capacity listed in Specifications/Performance Data Section
5th DIGIT - ALPHABETICAL MODIFIER 6th DIGIT - VOLTAGE
1 = 115 Volts 2 = 230 Volts 3 = 230-208 Volts
W S 07 A 1 0 B
7th DIGIT
0 = Straight Cool & Heat Pump Models ELECTRIC HEAT MODELS
1 = 1 KW Heat Strip, Nominal 3 = 3 KW Heat Strip, Nominal 4 = 4 KW Heat Strip, Nominal 5 = 5 KW Heat Strip, Nominal 8 = 8 KW Heat Strip, Nominal
8th DIGIT
Major Change
APPLICATION AND SIZING
In the application and sizing of room air conditioners for cooling, it is most important to give full consideration to all factors which may contribute to the heat loss or gain of the space to be conditioned. It is therefore necessary to make a survey of the space to be conditioned and calculate the load requirements before a selection of the size of the equipment needed can be made.
The load requirement may be determined very easily by simply using the standard “AHAM” Load Calculating Form, on Page 6. This form is very easy to use and is self explanatory. It is necessary only to insert the proper measurements on the lines provided and multiply by the giv en factors, then add the result f or the total load require­ments.
Cooling load requirements are generally based on the cooling load for comfortable air conditioning which does not require specific conditions of inside temperature and humidity. The load calculation form is based on outside design temperature of 95° FDB and 75° FWB. It can be used for areas in the Continental United States having other outside design temperatures by applying a correction factor for the particular locality as determined from the map shown on Page 6.
When sizing a TwinTemp unit for cooling and heating, we must remember that the heating capacity of any given unit varies directly with the outdoor ambient temperature. Also, we must keep in mind the average low tempera­tures which might be experienced in the locality where the unit is to be installed. Theref ore, when sizing a T winTemp unit, both cooling and heating requirements must be calculated. Do not oversize, or undersize, one phase of the unit’s capacity at the expense of the other. In those cases where the unit will provide satisfactory cooling at all times but will be inadequate for those few times that the outdoor temperature is below the maximum low for the unit, additional auxiliary heating facilities must be provided to insure that adequate heat is available at all times.
5
INSTRUCTIONS FOR USING COOLING LOAD ESTIMATE
FORM FOR ROOM AIR CONDITIONERS
(AHAM PUB. NO. RAC-1)
A. This cooling load estimate form is suitable for estimating the cooling load for comfort air conditioning installations
which do not require specific conditions of inside temperature and humidity.
B. The form is based on an outside design temperature of 95°F dry bulb and 75°F wet bulb. It can be used for areas
in the continental United States having other outside design temperatures by applying a correction factor for the particular locality as determined from the map.
C. The form includes "day" factors for calculating cooling loads in rooms where da ytime comfort is desired (such as
living rooms, offices, etc.)
D . The numbers of the following paragraphs refer to the corresponding numbered item on the f orm:
1. Multiply the square feet of window area f or each exposure b y the applicab le factor. The window area is the area of the wall opening in which the window is installed. For windows shaded b y inside shades or venetian blinds, use the factor for "Inside Shades." For windows shaded by outside awnings or by both outside awnings and inside shades (or venetian blinds), use the factor for "Outside Awnings." "Single Glass" includes all types of single thickness windows, and "Doub le Glass" includes sealed airspace types, storm windows, and glass b lock. Only one n umber should be entered in the right hand column for Item 1, and this number should represent only the exposure with the largest load.
2. Multiply the total square feet of all windows in the room b y the applicable factor.
3a. Multiply the total length (linear feet) of all walls e xposed to the outside by the applicab le factor . Doors should
be considered as being part of the wall . Outside walls facing due north should be calculated separately from outside walls facing other directions. Walls which are permanently shaded by adjacent structures should be considered “North Exposure.” Do not consider trees and shrubbery as providing permanent shading. An uninsulated frame wall or a masonry wall 8 inches or less in thickness is considered "Light Construction." An insulated wall or masonry wall over 8 inches in thickness is considered "Heavy Con­struction."
3b. Multiply the total length (linear feet) of all inside walls betw een the space to be conditioned and any uncon-
ditioned spaces by the given f actor . Do not include inside walls which separate other air conditioned rooms.
4. Multiply the total square feet of roof or ceiling area by the factor given for the type of construction most nearly describing the particular application (use one line only.)
5. Multiply the total square feet of floor area by the factor giv en. Disregard this item if the floor is directly on the ground or over a basement.
6. Multiply the number of people who normally occupy the space to be air conditioned by the f actor given. Use a minimum of 2 people.
7. Determine the total number of watts f or light and electrical equipment, except the air conditioner itself , that will be in use when the room air conditioning is operating. Multiply the total wattage by the factor given.
8. Multiply the total width (linear feet) of any doors or arches which are continually open to an unconditioned space by the applicable factor. NOTE: Where the width of the doors or arches is more than 5 feet, the actual load may exceed the calculated value . In such cases , both adjoining rooms should be considered as a single large room, and the room air conditioner unit or units should be selected according to a calculation made on this new basis.
9. T otal the loads estimated for the foregoing 8 items.
10. Multiply the subtotal obtained in item 9 by the proper correction factor, selected from the map, for the particular locality. The result is the total estimated design cooling load in BTU per hour.
E. For best results, a room air conditioner unit or units having a cooling capacity r ating (determined in accordance
with the NEMA Standards Publication for Room Air Conditioners, CN 1-1960) as close as possible to the esti­mated load should be selected. In general, a greatly oversized unit which would operate intermittently will be much less satisfactory than one which is slightly undersized and which w ould operate more nearly continuously.
F. Intermittent loads such as kitchen and laundry equipment are not included in this form.
6
COOLING LOAD ESTIMATE FORM
HEAT GAIN FROM
1. WINDOWS: Heat gain from the sun.
Northeast East Southeast South Southwest West Northwest North
2. WINDOWS: Heat by conduction
(Total of all windows.) Single glass Double glass or glass block
3. WALLS: (Based on linear feet of wall) a. Outside walls
North Exposure Other than North exposure
b. Inside Walls (between conditioned and
unconditioned spaces only.)
4. ROOF OR CEILING: (Use one only) a. Roof, uninsulated b. Roof, 1 inch or more insulation c. Ceiling, occupied space above d. Ceiling, insulated, with attic space above e. Ceiling, uninsulated, with attic space above
* These factors are for single glass
only. For glass block, multiply the above factors by 0.5; for double glass or storm windows, multiply the above factors by 0.8.
QUANTITY
____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft.
____sq. ft. ____sq. ft.
____ ft. ____ ft.
____sq. ft.
____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft. ____sq. ft.
FACTORS
DAY
No
Shades*
60 80 75
75 110 150 120
0
Light Construction
30 60
Inside
Shades*
Outside
Awnings*
25 40 30 35 45 65 50
0
14
30
19
12
20 ____ 25 ____ 20 ____ 20 ____ 30 ____ 45 ____ 35 ____
0 ____
7
Heavy Construction
8 3 5
BTU/Hr.
(Quantity x Factor)
(Area
X Factor)
____
Use
____
only
____
the
Use only one.
____ ____ ____ ____ ____
_____ _____
_____ _____
_____
_____ _____ _____ _____ _____
largest
load.
20 30
5. Floor: (Disregard if floor is directly on ground or over a basement.
6. NUMBER OF PEOPLE
7. LIGHTS AND ELECTRICAL EQUIPMENT IN USE
8. DOORS AND ARCHES CONTINUOUSLY OPENED TO UNCONDITIONED SPACE: (TOTAL LINEAR
FEET OF WIDTH.)
9. SUBTOTAL
10. TOTAL COOLING LOAD (BTU per hour to be used
for selection of room air conditioner(s).)
____ Total in Item 9 X ____(Factor from Map) = _______
____sq. ft.
____ ____watts
____ft.
*****
3
600
3
300
*****
_____
_____ _____
_____
_____
7
HEAT LOAD FORM
The heat load form, Page 8, may be used by servicing personnel to determine the heat loss of a conditioned space and the ambient winter design temperatures in which the unit will heat the calculated space.
The upper half of the form is for computing the heat loss of the space to be conditioned. It is necessary only to insert the proper measurements on the lines provided and multiply by the given factors, then add this result for the total heat loss in BTU/Hr./°F.
The BTU/Hr. per °F temperature difference is the 70°F inside winter designed temperature minus the lowest outdoor ambient winter temperature of the area where the unit is installed. This temperature difference is used as the multiplier when calculating the heat loss.
The graph shows the following: Left Hand Scale Unit capacity BTU/Hr . or heat loss
BTU/Hr.
Bottom Scale Outdoor ambient temperature,
base point.
Heat Pump Model BTU/Hr. capacity heat pump will
deliver at outdoor temperatures.
Balance Point Maximum BTU/Hr . heat pump will
deliver at indicated ambient temperature.
Below is an example using the heat load form: A space to be conditioned is part of a house
geographically located in an area where the lowest outdoor ambient winter temperature is 40°F. The calculated heat loss is 184 BTU/Hr./°F.
Subtract 40°F (lowest outdoor ambient temperature for the geographical location) from 70°F (inside design temperature of the unit) for a difference of 30°F . Multiply 184 by 30 for a 5500 BTU/Hr. total heat loss for the calculated space.
On the graph, plot the base point (70°) and a point on the 40°F line where it intersects with the 5500 BTU/Hr. line on the left scale. Dr aw a straight line from the base point 70 through the point plotted at 40°F. This is the total heat loss line.
Knowing that we ha ve a 5500 BTU/Hr. heat loss, and we expect that our heat pump will maintain a 70°F inside temperature at 40°F outdoor ambient, we plot the selected unit capacity BTU/Hr. of the unit between 35° and 60° on the graph and dr aw a straight line betw een these points . Where the total heat loss line and the unit capacity line intersect, read down to the outdoor ambient temperature scale and find that this unit will deliver the required BTU/ Hr. capacity to approximately 30°F.
8
HEATING LOAD FORM
FRIEDRICH ROOM UNIT HEAT PUMPS
BTU/HR PER
WALLS:(Linear Feet) °F TEMP. DIFFERENCE
2" Insulation Lin. Ft. x 1.6 Average Lin. Ft. x 2.6
WINDOWS & DOORS (Area, sq. ft.)
Single Glass: Sq. Ft. x 1.13 Double Glass: Sq. Ft. x 0.61
INFILTRATION - WINDOWS & DOORS: A VG. Lin. Ft. x 1.0
Loose Lin. Ft. x 2.0
CEILING: (Area, Sq. Ft.)
Insulated (6") Sq. Ft. x 0.07 Insulated (2") Sq. Ft. x 0.10 Built-up Roof (2" insulated Sq. Ft. x 0.10 Built-up Roof (1/2" insulated) Sq. Ft. x 0.20 No Insulation Sq. Ft. x 0.33
FLOOR: (Area, Sq. Ft.)
Above Vented Crawl space Insulated (1:) Sq. Ft. x 0.20 Uninsulated Sq. Ft. x 0.50 * Slab on Ground Lin. Ft. x 1.70 1" Perimeter insulation Lin. Ft. x 1.00
* Based on Linear Feet of outside wall TOTAL HEA T LOSS PER °F BTU/HR/°F Multiply total BTU/HR/°F X 30 and plot on the graph below at 40°F. Draw a straight line from
the 70 base point thru the point plotted at 40°F. The intersection of this heat loss line with the unit capacity line represents the winter design heating load.
9
SPECIFICATIONS WS07A10D WS10A10B WS12A10E-B WS12A30EB WS15A30B
BTUH 7400 10000 11500 12000 14700
11800 14500
E.E.R. 9.5 9.2 9.2 9.0 8.7
9.0 8.5
Volts 115 115 115 230 230
208 208
Amperes 7.0 9.8 11.5 6.0 7.7
6.5 8.5
T otal Watts 773 1081 1280 1333 1693
1310 1686 Hertz 60 60606060 Fuse/Breaker Size 15 15 15 15 15 Fan RPM 1145 1140 1275 1275 1275 Evaporator Air CFM 260 260 290 290 250 Fresh Air CFM Exhaust Air Ye s Yes Y es Y es Yes Dehumidification Pts/Hr 1.4 2.1 2.9 2.9 4.0 Width 27" 27" 27" 27 " 27" Height 16-3/4" 16-3/4" 16-3/4" 16-3/4" 16-3/4" Depth 16-3/4" 16-3/4" 16-3/4" 16-3/4" 16-3/4" Minimum Ext. Into Room 7-1/2" 7-1/2" 7-1/2" 7-1/2" 7-1/2" Minimum Ext. To Outside 9/16" 9/16" 9/16" 9 /16 " 9/16" Net Weight 75 85 94 91 101 Shipping Weight 93 103 112 109 119
PERFORMANCE DATA* Cooling
WS07A10D 59.5 19.5 82 280 7.0 32.0 19 11.8 WS09A10D 58.0 22.0 82 295 9.8 44.0 20 11.8 WS12A10D 55.0 25.0 76 295 11.5 54.0 36 11.8 WS12A30D 55.0 25.0 76 295 6.0 26.3 36 11.8
WS13A30D 47.1 32.9 73 308 7.7 33.0 38 11.8
*Rating Conditions: 80°F. Room Air Temperature and 50% Relative Humidity with
EVAPORATOR AIR OPERATING ELECTRICAL R-22 COMP.
TEMP. °F. PRESSURES RATINGS REFRIG. O IL
DISCHARGE TEMP. SUCTION DISCHARGE AMPS LOCKED CHARGE IN CHARGE IN
AIR DROP °F. ROTOR AMPS OUNCES FLUID OZ.
6.5
8.5
95°F. Outside Air Temper ature at 40% Relative Humidity.
10
SPECIFICATIONS W E0 7 A 3 3E C WE1 2 A3 3 E B WE15A33B WY09A33FA WY1 2 A 33 G A
BTUH (Cooling) 9000 12000 14700 9000 11500
8900 11800 14500 8900 11000
BTUH (Heating) 7000 11000 11000 7000 10500
7000 9100 9100 7000 10300
E.E.R. (Cooling) 8.7 9.0 8.7 8.6 9.0
9.0 8.6 9.3 9.0
E.E.R (Heating) 8.7 8.7 9.0
8.7 9.0
Volts 230 230 230 230 230
208 208 208 208 208
Amperes (Cooling) 4.3 6.0 7.7 3.6 5.8
4.6 6.5 8.5 4.0 6.2
Amperes (Heating) 16.0 16.0 16.93 16.7 16.0
14.7 14.7 16.86 14.7 14.7
Total Watts (Cooling) 973 1333 1693 973 1307
947 1310 1686 947 1273
Total Watts (Heating) 805 3550 3550 805 1167
805 2950 2950 805 1144 Hertz 6060606060 Fuse/Breaker Size 20 20 20 20 20 Fan RPM 1140 1275 1275 1140 1275 Evaporator Air CFM 260 290 250 27 0 290 Fresh Air CFM Exhaust Air CFM Yes Yes Y e s Yes Yes Dehumidification Pts/Hr 2.1 2.9 4.0 2.1 2.9 Width 27" 27" 27" 27" 27" Height 16 3/4" 16 3/4" 16 3/4" 16 3/4" 16 3/4" Depth 16 3/4" 16 3/4" 16 3/4" 16 3/4" 16 3/4" Minimum Ext. Into Room 7 1/2" 7 1/2" 7 1/2" 7 1/2" 7 1/2" Minimum Ext. To Outside 9/16" 9/16" 9/16" 9/16" 9/16" Net Weight 84 92 102 86 94 Shipping Weight 103 111 121 107 116
PERFORMANCE DATA* Cooling
EVAPORATOR AIR OPERATING ELECTRICAL R-22 COMP.
TEMP. °F. PRESSURES RATINGS REFRIG. OIL
DISCHARGE TEMP. SUCTION DISCHARGE AMPS LOCKED CHARGE IN CHARGE IN
AIR DROP °F. ROTOR AMPS OUNCES FLUID OZ.
WE09A33EC 58.0 22.0 80 295 4.3 20.0 20 11.8
4.6
WE12A33EB 55.0 25.0 76 295 6.0 26.3 36 11.8
6.5
WE15A33B 47.1 32.9 73 308 7.7 33.0 38 11.8
8.5
WY09A33FA 58.0 22.0 80 295 3.6 20.0 26 11.8
5.8
WY12A33GA 55.0 25.0 76 295 5.8 26.3 43 11.8
6.2
*Rating Conditions: 80°F. Room Air Temperature and 50% Relative Humidity with
PERFORMANCE VOLTS BTUH CFM HEAT RISE DATA (Heating) HIGH SPEED
95°F. Outside Air Temperature at 40% Relative Humidity.
WE09A33EC 230 11000 260 39.0
208 9100
WE12A33E-B 230 11000 290 35.0
208 9100
WE15A33GA 230 11000 250 40.0
208 9100
11
PERFORMANCE DATA *WY09A33FA *WY12A33GA (Heating)
BTUH @70°F Inside 62°F Outside 9700 12400
@70°F Inside 57°F Outside 9300 12000 @70°F Inside 52°F Outside 8800 11400
** @70°F Inside 47°F Outside 8200/8100 10800/10400
@70°F Inside 42°F Outside 7600 10000 @70°F Inside 37°F Outside 6800 9000 @70°F Inside 35°F Outside 11000/9100 11000/9100
Evaporator Air T emperature Rise
@70°F Inside 62°F Outside 32.00 37.60 @70°F Inside 57°F Outside 30.75 36.40 @70°F Inside 52°F Outside 29.10 34.50
** @70°F Inside 47°F Outside 27.10/26.80 32.70/31.50
@70°F Inside 42°F Outside 25.10 30.30 @70°F Inside 37°F Outside 22.50 27.30 @70°F Inside 35°F Outside 36.40/30.10 33.30/27.60
AMPS @70°F Inside 62°F Outside 4.0 5.6
@70°F Inside 57°F Outside 3.9 5.5 @70°F Inside 52°F Outside 3.85 5.4
** @70°F Inside 47°F Outside 3.8/4.1 5.3/5.6
@70°F Inside 42°F Outside 3.6 5.1 @70°F Inside 37°F Outside 3.4 4.8 @70°F Inside 35°F Outside 16.0/14.7 16.0/14.7
Watt s @70°F Inside 62°F Outside 880 1280
@70°F Inside 57°F Outside 870 1260 @70°F Inside 52°F Outside 860 1220
** @70°F Inside 47°F Outside 835/810 1175/1155
@70°F Inside 42°F Outside 800 1130 @70°F Inside 37°F Outside 760 1070 @70°F Inside 35°F Outside 3550/2950 3550/2950
Suction/Head PSIG
@70°F Inside 62°F Outside 66/315 61/325 @70°F Inside 57°F Outside 62/285 59/290 @70°F Inside 52°F Outside 57/285 53/275
** @70°F Inside 47°F Outside 53/265 49/255
@70°F Inside 42°F Outside 49/215 45/240 @70°F Inside 37°F Outside 45/203 41/220 @70°F Inside 35°F Outside 44/200 40/215
* Heating Element comes on at 35°F outside ambient and compressor shuts off. ** AHAM Rating Conditions.
12
COMPONENTS OPERATION & TESTING
WARNING
DISCONNECT ELECTRICAL POWER TO UNIT BEFORE SERVICING OR TESTING
COMPRESSORS
GROUND TEST
Use an ohmmeter set on its highest scale. Touch one lead to the compressor body (clean point of contact as a good connection is a must) and the other probe in turn to each compressor terminal (see Figure 2.) If a reading is obtained, the compressor is grounded and must be replaced.
Compressors are single phase, 115 or 230/208 volt, de­pending on the model unit. All compressor motors are permanent split capacitor type using only a running ca­pacitor across the start and run terminal.
All compressors are internally spring mounted and ex­ternally mounted on rubber isolators.
COMPRESSOR WINDING TEST Remove compressor terminal box cover and disconnect
wires from terminals. Using an ohmmeter, check conti­nuity across the following: (See Figure 1)
Figure 1: Compressor Winding Test
Figure 2: Typical Ground Test
CHECKING COMPRESSOR EFFICIENCY The reason for compressor inefficiency is normally due
to broken or damaged suction and/or discharge v alves , reducing the ability of the compressor to pump refriger­ant gas.
This condition can be checked as follows:
1. Install a piercing valve on the suction and dis­charge or liquid process tube.
1. Terminal “C” and “S” - no continuity - open wind­ing - replace compressor.
2. Terminal “C” and “R” - no continuity - open wind­ing - replace compressor.
3. Terminal “R” and “S” - no continuity - open wind­ing - replace compressor.
2. Attach gauges to the high and low sides of the system.
3. Start the system and run a “cooling or heating perf ormance test.”
If test shows: A. Below normal high side pressure. B. Above normal low side pressure. C. Low temperature difference across coil. The compressor valves are faulty - replace the
compressor.
THERMAL OVERLOAD (External)
Some compressors are equipped with an e xternal over­load which is located in the compressor terminal box adjacent to the compressor body (see Figure 3.)
13
The overload is wired in series with the common motor terminal. The overload senses both major amper age and compressor temperature. High motor temperature or amperage heats the disc causing it to open and break the circuit to the common motor terminal.
Figure 3: External Overload
Should the internal temperature and/or current draw become excessive, the contacts in the overload will open, turning off the compressor . The ov erload will automatically reset, but may require several hours before the heat is dissipated.
CHECKING THE INTERNAL OVERLOAD (see Figure
4.)
Figure 4
Heat generated within the compressor shell is usually due to:
1. High amperage.
2. Low refrigerant charge.
3. Frequent recycling.
4. Dirty condenser.
TERMINAL OVERLOAD - TEST
(Compressor - External Type)
1. Remove overload.
2. Allow time for ov erload to reset before attempting to test.
3. Apply ohmmeter probes to terminals on overload wires. There should be continuity through the overload.
TERMINAL OVERLOAD (Internal)
Some model compressors are equipped with an internal over load. The overload is embedded in the motor windings to sense the winding temperature and/or current draw. The overload is connected in series with the common motor terminal.
1. With no power to unit, remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not continuous, the compressor overload is open and the compressor must be replaced.
F AN MOTOR
A single phase permanent split capacitor motor is used to drive the evaporator b lower and condenser fan. A self­resetting overload is located inside the motor to protect against high temperature and high amperage conditions.
Although fan motors are lubricated at the factor y and sealed, oil ports are provided to lubricate to motor annually after the first year of operation (see Figure 5.) To lubricate (oil), remove the oil plugs on each end of the fan motor and put up to 30 drops of SAE10W30 grade motor oil in each hole, then replace oil plugs.
14
Figure 5: F an Motor
Figure 6: System Control Panel
F AN MOTOR - TEST
1. Determine that capacitor is serviceable.
2. Disconnect fan motor wires from fan speed s witch or system switch.
3. Apply “live” test cord probes on bl ack wire and common terminal of capacitor. Motor should run at high speed.
4. Apply “live” test cord probes on red wire and common terminal of capacitor. Motor should run at low speed.
5. Apply “live” test cord probes on each of the remaining wires from the speed switch or system switch to test intermediate speeds.
SYSTEM CONTROL SWITCH ("WS" Models)
A five position control switch is used to regulate the operation of the fan motor and compressor. The compressor can be operated with the fan operating at low, medium or high speed. The fan motor can also be operated independently on medium speed. See switch section as indicated on decorative control panel (see Figure 7.)
1. “Off” Position - no continuity between terminals.
2. “Lo Cool” Position - between terminals “L1” and “C”, “LO” and “MS”.
3. “Med Cool” Position - between terminals “L1” and “C”, “M” and “MS”.
4. “Hi Cool” Position - between terminals “L1” and “C”, “H” and “MS”.
5. “Fan Only” Position - between terminals “L1” and
Figure 7: System Control Switch
SYSTEM CONTROL SWITCH - TEST
Disconnect leads from control switch (see Figure 8.) There must be continuity as follows:
SYSTEM CONTROL SWITCH ("WE" & "WY" Models)
An eight position switch is used to regulate the opera­tion of the fan motor, compressor and electric heater.
15
The unit can be operated in cooling or heating mode with the compressor or electric heater on and the fan motor operating on low , medium or high speed.
The fan motor can also be operated independently on medium speed. See s witch section as indicated on deco­rative control panel, in Figure 8.
Figure 8: System Control Panel
Figure 9: System Control Switch
(Heat Pump & Electric Heat Models)
“2”.
NOTE: Units will operate in constant fan in the cool­ing mode and auto fan in the heating mode.
CAPACITOR, RUN
SYSTEM CONTROL SWITCH - TEST
Disconnect leads from control switch. Turn control to position being tested (see Figure 8.) There must be con­tinuity as follows:
1. "Off" Position-no contin uity between terminals.
2. "Lo Cool" Position-between terminals "C" and "3", "C2" and "2", "LO" and "M/S", "AR" and "5".
3. "Med Cool" Position-between terminals "C" and "3", "C2" and "2", "M" and "M/S", "AR" and "5".
4. "Hi Cool" Position-between terminals "C" and "3", "C2" and "2", "H" and "M/S", "AR" and "5".
5. "Hi Heat" Position-betw een terminals "C" and "1", "C2" and "4", "H" and "M/S", "AR" and "5".
6. "Med Heat" Position-between terminals "C" and "1", "C2" and "4", "M" and "M/S", "AR" and "5".
7. "Lo Cool" Position-between terminals "C" and "1", "C2" and "4", "LO" and "M/S", "AR" and "5".
8. "Fan Only" Position-between terminals "L1" and "M".
A run capacitor is wired across the auxiliary and main winding of a single phase permanent split capacitor mo­tor such as the compressor and fan motor. A single ca­pacitor can be used for each motor or a dual rated ca­pacitor can be used for both.
Figure 10: Run Capacitor Hook-Up
The capacitor’s primar y function is to reduce the line current while greatly improving the torque characteris­tics of a motor. The capacitor also reduces the line cur­rent to the motor by improving the power factor of the load. The line side of the capacitor is marked with a red dot and is wired to the line side of the circuit (see Figure
10.)
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