52S SERIES SERVICE TECHNICIAN GUIDE PACKAGED TERMINAL AIR CONDITIONERS AND HEAT PUMPS CONTENTS Page Page INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,3 SUMMARY OF DANGERS, WARNINGS, AND CAUTIONS . . . 2 GENERAL DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9 TO DISCONNECT POWER FOR CORD-CONNECTED UNIT . . 4 TO DISCONNECT POWER FOR PERMANENTLY CONNECTED (HARDWIRED) UNITS . . . . . . . . . . . . . . . . . . . 4 TO OPEN THE CONTROL BOX . . . . . . .
52S SERIES INTRODUCTION Knowing which model is being serviced will help determine if the unit is performing at optimum levels. The model number is located on the data information plate beneath the front panel of the unit. The data information plate also lists voltage ranges and other important electrical information about the unit. To access the data information plate, remove the front panel of unit by grasping panel on each side and gently pulling upward and out (Figure 1).
FIGURE 2 — MODEL NUMBER NOMENCLATURE FIGURE 3 — SAMPLE DATA INFORMATION PLATE 3
52S SERIES GENERAL DISASSEMBLY This section includes common procedures for disassembly and reassembly of 52S units. These instructions are general in nature and include procedures the technician may be called upon to perform when accessing certain components of the 52S unit. It is important to carefully follow manufacturer’s instructions when disassembling or reassembling a unit for cleaning, maintenance, or part replacement.
TO REMOVE THE LATERAL DUCT EXTENSION, FOR UNITS EQUIPPED WITH THE LATERAL DUCT ACCESSORY PACKAGE 1. Remove the front panel as shown in Figure 1. 2. Remove the four 13⁄4-in. screws that secure the chassis to the wall sleeve (see Figure 6). There are 2 screws on each side. 3. Remove the 2 screws that secure the lateral duct extension to the top of the lateral duct adapter as shown in Figure 7. FIGURE 7 — DUCT EXTENSION SCREWS 4.
52S SERIES TO ACCESS INDOOR-AIR SECTION COMPONENTS n DISASSEMBLING THE LATERAL DUCT ADAPTER, FOR UNITS EQUIPPED WITH THE LATERAL DUCT ACCESSORY PACKAGE 1. Remove the lateral duct adapter end cap, shown in Figure 10, by removing the two 1⁄2-in. screws 2. Remove the adapter top panel by removing one screw at each end of unit as shown in Figure 11. Rotate the front of the panel up and back and lift free. 3. Rotate and lift the air baffle out of the unit. See Figure 12. 4.
n TO REMOVE THE AIR DISCHARGE GRILLE 1. Remove the 2 screws on each end of the air discharge grille as shown in Figure 14. 2. Lift and rotate back the bottom edge of the discharge grille and remove it. FIGURE 14 — REMOVING AIR DISCHARGE GRILLE n TO REMOVE THE ALUMINUM TOP PANEL — Remove one screw from each end of the aluminum top panel (located on the underside of the panel) as shown in Figure 15. On the left side of the unit, remove the screw closest to the side of the unit.
52S SERIES DISCHARGE DECK SCREWS n TO REMOVE THE DISCHARGE DECK 1. Remove the 2 discharge deck screws shown in Figure 17. Also remove the screw located at the top left corner of the outdoor coil tube sheet. 2. Gently pull the left side panel out and lift the end of the discharge deck that the screws were removed from, up and forward, to remove. FIGURE 17 — DISCHARGE DECK REMOVAL CONDENSER ORIFICE TO ACCESS OUTDOOR-AIR SECTION COMPONENTS GUSSET n TO REMOVE THE GUSSET 1.
STATOR CONDENSER ORIFICE n TO REMOVE THE STATOR — After pulling the top of the condenser orifice away from the condenser coil, grasp the top of the stator and slide it up and out of the stator track. See Figure 20.
52S SERIES GENERAL CLEANING Maintaining proper performance of 52S systems (Figure 21) requires conscientious cleaning and care of components. Specific components require periodic cleaning and/or replacement, including the following: Before cleaning, servicing, performing maintenance, or removing the chassis from the wall sleeve, disconnect all power to the unit to avoid the possibility of electrical shock and personal injury.
TOOLS NEEDED MONTHLY CLEANING The following list includes the recommended tools, devices, and cleaning solutions for use in cleaning the 52S unit components. n AIR FILTERS — The indoor and vent air filters should be cleaned once per month. Filters that are not cleaned become clogged and will restrict airflow. This may lead to major component damage. If a filter becomes torn, has holes, or other damage, replace it with a new one.
52S SERIES n CLEANING THE VENT AIR FILTER 1. Remove the unit chassis from wall sleeve as described in the General Disassembly section of this manual. See Figure 6. 2. Swing open vent door. The filter is located directly behind the vent door. See Figure 23. 3. Remove the vent air filter by gently pushing on the filter slot. Once the vent air filter is removed, it may be cleaned using either a vacuum cleaner, or a soft bristle brush and a small amount of mild dish detergent.
9. Remove the stator from the outdoor coil. See SEASONAL CLEANING GENERAL DISASSEMBLY section. After cleaning, reassemble by reversing steps 1 - 8. n ACCESSING THE INDOOR AND OUTDOOR COILS — The minimum cleaning recommendation for indoor and outdoor coils is once per season. To access the coils for a thorough cleaning, it is necessary to remove the Air System. To accomplish this task, perform the following steps: 1. DISCONNECT ALL POWER TO UNIT! 2.
52S SERIES n CLEANING THE INDOOR AND OUTDOOR COILS Coil fins are sharp and may cut hands. Wear heavy protective gloves when cleaning coils. 1. Use a vacuum cleaner or soft bristle brush to remove 2. 3. 4. 5. surface fibers and dirt from each of the faces of the coil. Both the inner and outer surfaces of the coils must be cleaned. It is important to apply the tool in the same direction of the fins, not against them. Applying the tool against the fins may cause damage (fin edges may bend over).
n CLEANING THE INDOOR FAN AND FAN SCROLL — Once the indoor fan wheel and the indoor fan scroll have been accessed, proceed with the cleaning instructions detailed below: 1. Insert a piece of 9.5-in. by 9.5-in. cardboard between the blower wheel and the opening in the blower scroll to prevent fungus and other debris from falling into the coil. 2. Bend a soft, spiral wound, long bristle brush, to conform to the inner curve of the blower wheel blades. See Figure 30. 3.
52S SERIES COMPRESSOR A cutaway view of the rotary compressor with key components labeled is shown in Figure 32. The motor stator is rigidly attached to the compressor shell. The rotor is pressed onto the eccentric shaft, which is supported by 2 bearings. Both the discharge valve and discharge muffler are attached to the motor bearing. The pump bearing provides a thrust surface for the shaft and the rolling piston. Compressed gas is separated from the suction gas by the vane.
The rotary compression process (Figure 33), starts at top dead center as shown in (1). Suction gas flows through the suction inlet and into the cylinder area. As the shaft rotates through 90 degrees, the rolling piston moves to position A as shown in (2). The suction volume is now the area defined by point A and the tip of the vane. Gas in the remaining volume has been compressed above suction pressure. After another 90 degrees of shaft rotation, the rolling piston has moved to position B as shown in (3).
52S SERIES SYMPTOM g POSSIBLE CAUSE f COILS/FILTERS DIRTY OR PLUGGED AIR OR NONCONDENSABLE GASES IN SYSTEM SYSTEM REFRIGERANT OVERCHARGED DISCHARGE LINE RESTRICTED CAPILLARY TUBE OR STRAINER RESTRICTED OR PLUGGED FAN BLADE OR MOTOR DEFECTIVE FAN BLADE OR BLOWER WHEEL STUCK SYSTEM REFRIGERANT UNDERCHARGED EVAPORATOR AIRFLOW RECIRCULATION UNIT OVERSIZED FOR APPLICATION COMPRESSOR REQUIRES START ASSIST NO POWER TO UNIT LOW VOLTAGE TO UNIT OVERLOAD PROTECTOR OPEN OVERLOAD PROTECTOR INCORRECT OR DEFECTIVE CA
5. Next, test the resistance individually of each wire to COMPRESSOR REPLACEMENT the shell of the compressor. The paint on the compressor can prevent good contact between the probe and the metal. The paint should be removed from a small section of the shell of the compressor to ensure good contact by the meter probe. The volt-ohmmeter should be set to at least the 100X ohm level. The measured resistance between each wire and ground should be infinite or O.L. on the readout.
52S SERIES n REMOVING THE COMPRESSOR — Follow the steps below to remove the compressor: 1. Disconnect all power to unit. 2. Remove unit from wall sleeve as detailed in the GENERAL DISASSEMBLY section. The unit weighs up to 150 pounds. Seek assistance or use a lifting device when removing unit from wall sleeve. 3. If the unit is a heat pump: Disconnect the wire plug on the reversing valve solenoid and carefully remove the outdoor thermostat capillary from the outdoor coil. 4.
10. For Heat Pump Units remove the capillary tube only. 11. For Heat/Cool Units the filter drier is installed in 12. 13. 14. 15. 16. 17. 18. 19. the liquid line, in place of the strainer. Trim the saved liquid line tube from Step 9, to be 1.5 in. long (saving the crimped portion), and braze it into the filter drier, Part No. KH43LG060. See Figure 39. For Heat Pump Units: A suction line filter drier (Part No.
52S SERIES HEATERS The heater in 52S units is located directly behind the evaporator coil. The heater assembly includes the heater (2.3 kW, 3.4 kW or 5 kW), a primary limit switch, and a secondary limit switch (Figure 41). The primary and secondary limit switches are safety switches that regulate heater operation. The primary limit switch disables current to the heater when the temperature exceeds the setting on the switch. For example, a 3.4 kW heater may have a primary limit switch setting of 150 F.
3. Remove the unit from the sleeve as detailed in the GENERAL DISASSEMBLY section. 4. Remove the discharge air grille and the discharge air deck as detailed in the GENERAL DISASSEMBLY section. Save screws. 5. Once the air discharge deck is removed, the heater assembly is exposed. After noting positions of wires and labelling them, use a pair of needle nose pliers to carefully remove the wires connected to the heater assembly. 6. Remove the two 1⁄4-in.
52S SERIES OPERATING CONTROLS The controls and components used in the 52S cooling only or heat/cool units are as follows: the selector switch, the indoor thermostat, the dual capacitor, the temperature limiter, the vent lever, and the fan cycle switch (Figure 45). The selector switch is used to determine the mode of operation: heat, cool, fan, or off. The indoor thermostat controls the room ambient temperature and cycles the heater or the compressor based on the selector switch setting.
DESCRIPTION OF SWITCH SETTINGS NON-USER ADJUSTABLE SWITCHES n OFF BUTTON — The OFF button terminates unit n OUTSIDE OR VENT AIR — Push the FAN ONLY button and slide vent lever to OPEN position. n FAN ONLY BUTTON — Push button for air circulation without heating or cooling. n FAN CYCLE — The fan cycle switch allows the fan to operate in 2 modes: CON — Fan runs continuously, circulating air even when the temperature setting has been satisfied.
52S SERIES SEQUENCE OF OPERATION SWITCH POSITION OFF FAN LO COOL HI COOL n HEAT/COOL UNITS (Figure 50) Fan Mode — With the selector switch set to FAN and the fan switch set to fan cycle, contacts L1 to LO and FCS1 to LS are made. Cooling (Low) — With the selector switch set to low speed cooling and the fan switch set to fan cycle, contacts FCS2 to LO, COMP to FCS1, and COMP to IT3 are made. NOTE: The contact in low cooling sequence of operation for FCS2 is MED on units built prior to 1996.
To verify the operation of the thermostat switch, a continuity test may be performed as follows: 1. Turn off unit power as described in GENERAL DISASSEMBLY section. 2. Remove wire leads from thermostat. Note their locations to ease re-assembly. 3. Place one of the leads of the continuity tester on the terminal marked 2, and the other lead on either the terminal marked 1 or the terminal marked 3. 4. Adjust the thermostat up or down to verify the contacts of the switch open and close.
52S SERIES n INDOOR THERMOSTAT (Heat Pump Units) (cont) (Figure 54) — To verify operation of the heat pump indoor thermostat switch, a continuity test may be performed as follows: 1. Turn off unit power as described in GENERAL DISASSEMBLY section. 2. Remove wire leads from thermostat. Note their locations to ease re-assembly. 3. To test stage A, place one lead of the continuity tester on the terminal marked 2, and the other lead on either the terminal marked 1 or the terminal marked 3. 4.
n CAPACITOR — The 52S units use a dual capacitor. One part of the capacitor is used with the fan motor. The other part of the capacitor is used by the compressor. Run circuits on single-phase compressor motors use capacitors which dramatically affect the motor operation. Run capacitors are connected to the motor circuit at all times. To evaluate the capacitor, perform a visual check first. A shorted capacitor may give a visual indication of its failure.
52S SERIES n OUTDOOR FROST THERMOSTAT (Heat Pump Units) ELECTRICAL COMPONENTS REMOVAL AND REPLACEMENT — To remove the outdoor frost thermostat (OFT), perform the following steps: 1. Turn off unit power as described in GENERAL DISASSEMBLY section. 2. Remove the 2 screws mounting the thermostat to the right side of the control box. See Figure 60. 3. Remove the thermostat capillary from the outdoor coil and clip any wire ties holding the capillary in place. 4.
n CAPACITOR — To remove the capacitor, perform the following steps: 1. Turn off unit power as described in GENERAL n FAN CYCLE SWITCH — The fan cycle switch is lo- cated on the right side of the control box. To remove the fan cycle switch, perform the following steps: 1. Turn off unit power as described in GENERAL DISASSEMBLY section. 2. Open the control box as described in GENERAL DISASSEMBLY section of this manual. 3. Remove the 3 wires from the fan cycle switch. See Figure 61 for location. 4.
52S SERIES FAN MOTOR The fan motor is a permanent split capacitor (PSC) type motor. This motor is common in air-conditioning system applications. A PSC motor does not require the use of a relay and always has a run capacitor connected between the run and start windings of the motor. See Figure 62. The 52S series fan motor has a motor shaft extended through both ends. It powers both the indoor and the outdoor fans. It has permanently sealed bearings that require no lubrication.
SYMPTOM g POSSIBLE CAUSE f DEFECTIVE BEARING CAPACITOR DEFECTIVE SWITCH DEFECTIVE LOW LINE VOLTAGE SHORTED MOTOR WINDING NO POWER TO UNIT INTERNAL THERMOSTAT OPEN MISWIRED FAN STUCK BROKEN MOTOR WIRE MOTOR WINDING GROUNDED OPEN MOTOR WINDING MOTOR HUMS BUT DOES NOT START MAKES NO NOISE AND DOES NOT START STARTS BUT STOPS AFTER SHORT TIME STARTS BUT RUNS SLOW X X X X X X X RUNS ON ONE SPEED, NOT ON OTHERS X X X X X X X X X X X X X X X X X X X X X X X FIGURE 63 — FAN MOTOR TROUBLESHOOTI
52S SERIES FAN MOTOR REPLACEMENT Perform the following steps to remove and reinstall the fan motor: 1. DISCONNECT ALL POWER TO UNIT. 2. Remove the unit from the sleeve as detailed in the GENERAL DISASSEMBLY section and place the unit on a large flat surface. 3. Remove the discharge air grille, the aluminum top panel, the top cover, and the discharge air deck as detailed in the GENERAL DISASSEMBLY section under To Access Indoor-Air Section Components (Figures 14 - 17). Save the screws. 4. Remove 5⁄16-in.
FIELD TEMPERATURE CHARTS See Figures 67 - 82 for field temperature data.
52S SERIES 36 FIGURE 68 — 52S 7,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH
FIGURE 69 — 52S 7,000 BTU UNIT FIELD TEMPERATURE CHART, LOW HEAT MODE (47 F OUTDOOR TEMPERATURE)
52S SERIES 38 FIGURE 70 — 52S 7,000 BTU UNIT FIELD TEMPERATURE CHART, HIGH HEAT MODE (47 F OUTDOOR TEMPERATURE)
FIGURE 71 — 52S 9,000 BTU UNIT FIELD TEMPERATURE CHART — LOW COOL — 50% RH
52S SERIES 40 FIGURE 72 — 52S 9,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH
FIGURE 73 — 52S 9,000 BTU UNIT FIELD TEMPERATURE CHART, LOW HEAT MODE (47 F OUTDOOR TEMPERATURE)
52S SERIES 42 FIGURE 74 — 52S 9,000 BTU UNIT FIELD TEMPERATURE CHART, HIGH HEAT MODE (47 F OUTDOOR TEMPERATURE)
FIGURE 75 — 52S 12,000 BTU UNIT FIELD TEMPERATURE CHART — LOW COOL — 50% RH
52S SERIES 44 FIGURE 76 — 52S 12,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH
FIGURE 77 — 52S 12,000 BTU UNIT FIELD TEMPERATURE CHART, LOW HEAT MODE (47 F OUTDOOR TEMPERATURE)
52S SERIES 46 FIGURE 78 — 52S 12,000 BTU UNIT FIELD TEMPERATURE CHART, HIGH HEAT MODE (47 F OUTDOOR TEMPERATURE)
FIGURE 79 — 52S 14,000 BTU UNIT FIELD TEMPERATURE CHART — LOW COOL — 50% RH
52S SERIES 48 FIGURE 80 — 52S 14,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH
FIGURE 81 — 52S 14,000 BTU UNIT FIELD TEMPERATURE CHART, LOW HEAT MODE (47 F OUTDOOR TEMPERATURE)
52S SERIES 50 FIGURE 82 — 52S 14,000 BTU UNIT FIELD TEMPERATURE CHART, HIGH HEAT MODE (47 F OUTDOOR TEMPERATURE)
WIRING SCHEMATICS Refer to Figures 83 - 87 for typical 52S unit wiring schematics. NOTE: Figures 83 - 87 should not be substituted for the schematic located next to the unit control box. LEGEND FCS — Fan Cycle Switch IT — Indoor Thermostat L — Power Supply Line Component Connections (Marked) Component Connection (Unmarked) Accessory or Optional Wiring Factory Wiring NOTES: 1. Recommended for use on grounded power supply only. 2. Compressor and fan motor thermally protected. 3. Use copper conductors only.
S SERIES LEGEND CAP COMP FCS FM HTR IT L OL PL PLS SLS — — — — — — — — — — — Capacitor Compressor Fan Cycle Switch Fan Motor Heater Indoor Thermostat Power Supply Line Overload Plug Primary Limit Switch Secondary Limit Switch ST — Start Thermistor SW — Selector Switch Component Connection (Marked) SWITCH POSITION OFF FAN Component Connection (Unmarked) Accessory or Optional Wiring Factory Wiring To Indicate Common Potential Only. Not to Represent Wire NOTES: 1.
LEGEND CAP — Capacitor COMP — Compressor CR — Cooling Relay EQUIP GND — Equipment Ground FM — Fan Motor FR — Fan Relay HR — Heating Relay IFT — Indoor Frost Thermostat L — Power Supply Line OL — Overload PL PLS SLS SSS ST TB TRANS — — — — — — — Plug Primary Limit Switch Secondary Limit Switch Speed Selector Switch Start Thermistor Terminal Board Transformer Component Connection (Marked) NOTES: 1. Recommended for use on grounded power supply only. 2. Compressor and fan motor thermally protected. 3.
52S SERIES CAP COMP FCS FM HTR IT L OL PL PLS RVS SLS — — — — — — — — — — — — Capacitor Compressor Fan Cycle Switch Fan Motor Heater Indoor Thermostat Power Supply Line Overload Plug Primary Limit Switch Reversing Valve Solenoid Secondary Limit Switch LEGEND ST — Start Thermistor SW — Switch Component Connection (Marked) Component Connection (Unmarked) Accessory or Optional Wiring Factory Wiring To Indicate Common Potential Only.
CAP — Capacitor COMP — Compressor CR — Cooling Relay EQUIP GND — Equipment Ground FM — Fan Motor FR — Fan Relay HR — Heating Relay IFT — Indoor Frost Thermostat L — Power Supply Line OFT — Outdoor Frost Thermostat OL PL PLS RVR RVS SLS SSS ST TB TRANS — — — — — — — — — — LEGEND Overload Plug Primary Limit Switch Reversing Valve Relay Reversing Valve Solenoid Secondary Limit Switch Speed Selector Switch Start Thermistor Terminal Board Transformer NOTES: 1.
52S SERIES MOST FREQUENT PTAC SERVICE QUESTIONS 1. Can remote thermostats be used on standard (AA) models? 2. Which remote thermostats are acceptable for use on 52S products? 3. How many 52S series units can be controlled by one remote thermostat? 4. What is the vent capacity of the 52S products? 5. How do the 52S series models handle condensate removal? 6. At what temperature will the outdoor (defrost) thermostat switch the unit (heat pumps only) into defrost (emergency heat) mode? 7.
