52C,P SERIES SERVICE TECHNICIAN GUIDE PACKAGED TERMINAL AIR CONDITIONERS AND HEAT PUMPS CONTENTS Page INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,3 SUMMARY OF DANGERS, WARNINGS, AND CAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 UNIT DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,4 TOOLS NEEDED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 REMOVE FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . .
52C,P SERIES INTRODUCTION The focus of this manual is to provide basic information on service procedures, safety, troubleshooting, cleaning, and component replacement for service technicians. It is intended for use only by HVAC service technicians who have successfully completed instruction and received Type I Certification from the U.S. Environmental Protection Agency.
52 PQ A 3 12 Series Designation PTAC (Packaged Terminal Air Conditioner) CE CQ PC PE PQ – – – – – 3 0 1 AA Chassis Options Blank or AA – Standard CP – Corrosion Protection RC – Wall Thermostat Control RP – Wall Thermostat Control with Corrosion Protection Cooling with Electric Heat Heat Pump with Electric Heat Cooling Only Cooling with Electric Heat Heat Pump with Electric Heat Latest Revision A– Z Packaging 1 – Domestic Electric Heater Size 0 – No Heating (Cooling Only Model) 2 – 2.
52C,P SERIES OPEN THE CONTROL BOX The control box is factory wired. To open the box, remove the 2 screws on the top of the control box and lower the front hinged panel. See Figure 6. REMOVE THE UNIT FROM THE WALL SLEEVE 1. Remove the four mounting screws that secure the PTAC unit to the wall sleeve (2 screws per side). See Figure 7. 2. Grasp the sides of the unit and slide it from the sleeve. NOTE: The mounting screws may be in a different location depending on brand of wall sleeve attached.
CONTROL BOX SCREWS VARIOUS ATTACHMENT HOLE LOCATIONS POWER CORD ACCESS COVER AMANA, TRANE (SLOTTED HOLES) WALL SLEEVE HOLES POWER CORD FIGURE 6 — CONTROL BOX COVER GE WALL SLEEVE HOLES CARRIER, BRYANT WALL SLEEVE HOLES FIGURE 7 — PTAC UNIT TO WALL SLEEVE MOUNTING SCREWS ACCESSING UNIT COMPONENTS ■ ACCESSING INDOOR-AIR SECTION COMPONENTS ACCESSING THE HEATER ASSEMBLY — Once the discharge deck assembly is removed, the Heater Assembly should now be accessible. See Figure 10. 1.
52C,P SERIES END CAP PLENUM LATERAL DUCT EXTENSION TOP SCREWS (2) WALL BRACKET SCREWS RIGHT BRACKET LEFT BRACKET BRACKET SCREWS FIGURE 8 — PTAC UNIT WITH LATERAL DUCT ACCESSORY INSTALLED DISCHARGE DECK FIGURE 10 — ACCESSING HEATER PLATE ASSEMBLY ATTACHMENT SCREWS HEATER PLATE ASSEMBLY DISCHARGE SCREEN DISCHARGE DECK FIGURE 9 — LOCATION OF ATTACHMENT SCREWS ON DISCHARGE DECK OF UNIT FIGURE 11 — REMOVAL OF HEATER PLATE ASSEMBLY DETACH THE CONDENSER ORIFICE FROM THE CONDENSER COIL 1.
GUSSET GUSSET SCREWS CONDENSER ORIFICE (PLASTIC) GUSSET SCREWS PARTITION FIGURE 14 — PRYING CONDENSER ORIFICE AWAY FROM TUBE SHEET GUSSET FIGURE 12 — GUSSET REMOVAL CONDENSER ORIFICE CAPTIVE SCREWS (2) CAPTIVE SCREWS (2) FIGURE 15 — REMOVING TOP OF CONDENSER ORIFICE FIGURE 13 — LOCATION OF CAPTIVE SCREWS ON CONDENSER ORIFICE 7
52C,P SERIES CONDENSER FAN OUTDOOR COIL TUBE SHEET SCREWS HUB CLAMP FIGURE 16 — LOCATION OF OUTDOOR COIL TUBE SHEET SCREWS FIGURE 18 — REMOVING CONDENSER FAN HUB CLAMP CONTROL DOOR HINGE PINS SCREW FRONT PANEL (BACK VIEW) SCREW DISCHARGE GRILLE FIGURE 19 — LOCATION OF SCREWS ON DISCHARGE GRILLE REINSTALL FRONT PANEL 1. Grasp the front panel firmly at the center of the top and bottom of the panel, tilting it forward 5 to 10 degrees from the vertical. See Figure 4. 2.
GENERAL CLEANING Maintaining proper performance of 52C,P systems requires conscientious cleaning and care of components. See Figure 20. Specific components require periodic cleaning and/or replacement, including the following: Consider the following safety issues before beginning: • New and unfamiliar tasks should be performed under the supervision of an experienced service technician. • Personal protective equipment, such as safety glasses and work gloves, should be used.
52C,P SERIES ■ TOOLS NEEDED REPLACING THE INDOOR AIR FILTER — Remove the indoor air filter as detailed in Cleaning the Indoor Air Filter. If damaged, use a filter replacement with the Carrier Part No. AIR-FILTER-10PK, available through Carrier Finished Goods and Carrier Replacement Component Division. NOTE: Both filters are completely interchangeable. ■ CLEANING THE OUTDOOR AIR VENT FILTER 1. Remove the unit chassis from wall sleeve as described in the General Disassembly section of this manual.
SEASONAL CLEANING The indoor and outdoor coils should be cleaned at least once during every season. Refer to ACCESSING UNIT COMPONENTS section to prepare unit. ■ CLEANING THE INDOOR AND OUTDOOR COILS Do not set unit on end to drain water from basepan, or at any other time. Oil will drain from the compressor sump, which could cause compressor failure. 6. Thoroughly clean the basepan and drain passages by rinsing with clean water. Be sure all debris is removed from the drain valve. See Figure 26. 7.
52C,P SERIES FIGURE 23 — PTAC EXTERIOR SURFACES FIGURE 25 — CLEANING COILS FIGURE 24 — VACUUMING EVAPORATOR COIL DRAIN VALVE FIGURE 26 — BASEPAN SECTION 12
COMPRESSOR pump bearing provides a thrust surface for the shaft and the rolling piston. Compressed gas is separated from the suction gas by the vane. Discharge gas pressure and the vane spring keep the vane in contact with the rolling piston. A cutaway view of the rotary compressor with key components labeled is shown in Figure 27. The motor stator is rigidly attached to the compressor shell. The rotor is pressed onto the eccentric shaft, which is supported by 2 bearings.
52C,P SERIES BASIC HERMETIC COMPRESSOR ELECTRICAL MEASUREMENTS The rotary compression process (Figure 28), 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.
POSSIBLE CAUSE 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 CAPACITOR INCORRECT OR DEFEC
52C,P SERIES ■ 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 UNIT 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. See Figure 32. 4.
12. Install the new compressor and the new capillary assembly (the correct capillary and strainer may be obtained from Carrier RCD), into the unit. 13. Leak check the unit with 150 psi of nitrogen pressure. 14. For 52C,P units, the system should be evacuated from the high side to the low side to a minimum of 200 microns of mercury. This evacuation removes residual moisture from the system prior to charging. 15. For Heat Pump Units: Recharge unit to the nameplate refrigerant charge using a charging cylinder.
52C,P SERIES HEATERS COMMON CAUSES OF HEATER FAILURE The heater in 52C,P 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. See Figure 34. 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.
■ TOOLS NEEDED — The following list includes recommended tools and devices for working on the heater section of 52C,P units. Coil resistance must also be checked to verify the heater is operating correctly. The resistance of the heater coils must meet approximate levels for the heater to perform at its optimum efficiency. See Figure 36 for approximate resistance for heaters at 75 F. Before checking the heater coil resistance, be sure all power to unit is off.
52C,P SERIES OPERATING CONTROLS UNIT-MOUNTED CONTROLS The 52C,P heat pump unit contains all the components of the heat/cool and cooling only unit, and the following additional ones: the outdoor frost thermostat and the reversing valve. The outdoor frost thermostat prevents operation of the unit in the heat pump mode when the outdoor coil temperature drops below 20 F, or at about 35 F outdoor ambient temperature.
WALL-MOUNTED THERMOSTAT CONTROLS For 52C,P wall thermostat control (RC, RP) units, all controls are located on the wall-mounted thermostat except the vent lever and outdoor thermostat. Remote control is a factory or field-installed option. There are 3 styles of thermostats qualified for use with 52C,P series Remote Control units. See Figures 38-40. On remote control units, the fan cycle function is located on the wall thermostat.
52C,P SERIES MASTER PTAC R R Y Y W W G G O O C C T’STAT R UNIT 1 Y W G O C R UNIT 2 Y W G O C R UNIT 3 Y W NOTES: 1. Do not daisy chain R (24 VAC). 2. Maximum of 4 PTAC units can be connected to one single wall thermostat. G O C All units must be connected to same ground source. To accomplish this, be sure to connect all units back to the same breaker box.
DESCRIPTION OF SELECTOR SWITCH SETTINGS (Figure 44) NON-USER ADJUSTABLE CONTROLS ■ ■ OFF MODE — The OFF position terminates unit operation. OUTSIDE OR VENT AIR — Slide the vent lever to the fully open position for outside air or fully closed position for vented air. ■ ■ 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.
52C,P SERIES Cooling (High) — With the selector switch set to high cool, contacts L1 to IT3 and FCS to HI are made. Heating (Low) — With the selector switch set to low heat contacts L1 to IT1, FCS to LO and L2 to HTR are made. Heating (High) — With the selector switch set to high heat contacts L1 to IT1, FCS to HI, and L2 to HTR are made. Defrost Cycle — When heat pump unit is operating in reverse cycle, the outdoor coil may begin to frost.
The Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. 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. When verifying continuity of a closed switch, the ohm reading should be 0 ohms.
52C,P SERIES 1 To verify the OFT is operational, a continuity test may be performed as follows: 1. Turn off unit power as described in UNIT DISASSEMBLY section. 2. Remove the leads from the OFT. Note their locations to ease re-assembly. 3. Connect the continuity tester to the switch terminals marked 1 and 2. 4. Rotate the override switch to the electric heat setting and verify that there is continuity between terminals 1 and 2. 5. To check the other contacts, move the lead on terminal 1 to terminal 3.
7. Remove the 2 screws mounting the thermostat to the control box. Route thermostat bulb and capillary out of control box. 8. Remove thermostat. 9. Reverse Steps 1-8 to reinstall. ■ OUTDOOR FROST THERMOSTAT (Heat Pump Units) — To remove the outdoor frost thermostat (OFT), perform the following steps: 1. Turn off unit power as described in UNIT DISASSEMBLY section. 2. Remove front panel. 3. Remove the 2 screws mounting the thermostat to the bottom of the control box. See Figure 53.
52C,P SERIES ■ 4. Remove the thermostat capillary from the outdoor coil and clip any wire ties holding the capillary in place. 5. Disconnect the wires and carefully remove the thermostat and capillary from the unit, noting location of wires for easy re-assembly. 6. Reverse Steps 1-5 to reinstall. SELECTOR SWITCH — To remove the selector switch from the unit, perform the following steps: 1. Turn off unit power as described in UNIT DISASSEMBLY section. 2. Remove selector switch knob. See Figure 53. 3.
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 55. The 52C,P 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.
52C,P SERIES POSSIBLE CAUSE 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 X X Makes No Noise and Does Not Start SYMPTOM Starts But Stops After Short Time X X Starts But Runs Slow 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 X X FIGURE 56 — FAN MOTOR TROUBLESH
FAN MOTOR REPLACEMENT 9. Remove the top half of the condenser orifice as detailed in Detach the Condenser Orifice From the Condenser Coil section. 10. Using a Phillips head screwdriver, remove the fan motor shield. The fan motor mounting screws should now be accessible. Remove the 3 mounting screws that secure the fan motor to the motor mount and remove the fan motor from the unit. 11. Using needle nose pliers, remove condenser fan hub clamp. Slide condenser fan off fan motor shaft. 12.
Indoor Coil Delta Temperature (F) 32 14 16 18 20 22 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 120 FIGURE 59 — 52C AND 52P 7000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 130 52C,P SERIES FIELD TEMPERATURE CHARTS Refer to Figures 59-67 for field temperature data.
Indoor Coil Delta Temperature (F) 16 18 20 22 24 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 120 FIGURE 60 — 52C AND 52P 9000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 130
Indoor Coil Delta Temperature (F) 34 18 20 22 24 26 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 FIGURE 61 — 52P 12,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 120 130 52C,P SERIES
Indoor Coil Delta Temperature (F) 20 22 24 26 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 120 FIGURE 62 — 52CQ 12,000 BTU HEAT PUMP UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 130
Indoor Coil Delta Temperature (F) 36 18 20 22 24 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 120 FIGURE 63 — 52CE 12,000 BTU HEAT/COOL UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 130 52C,P SERIES
Indoor Coil Delta Temperature (F) 18 20 22 24 26 28 50 80 90 100 75 F Indoor 80 F Indoor Outdoor Air Temperature (F) (40% RH) 70 F Indoor 70 85 F Indoor 110 120 FIGURE 64 — 52C AND 52P 15,000 BTU UNIT FIELD TEMPERATURE CHART — HIGH COOL — 50% RH 60 130
Indoor Air Temperature Rise (F) 38 20 25 30 35 40 52 54 56 60 62 64 66 208 V, 2.3 kW 208 V, 3.4 kW 230/265 V, 2.3 kW 230/265 V, 3.
15 20 25 30 35 40 45 50 52 54 56 60 62 64 66 230/265 V, 5.0 kW 230/265 V, 3.4 kW 230/265 V, 2.3 kW 208 V, 5.0 kW 208 V, 3.4 kW 208 V, 2.
Indoor Air Temperature Rise (F) 40 50 52 54 56 60 62 64 15,000 Btu 52C-12,000 Btu 52P-12,000 Btu 9,000 Btu 7,000 Btu Indoor Entering Air Temperature (F) 58 66 68 70 72 FIGURE 67 — 52C AND 52P 7,000-15,000 BTU UNIT FIELD TEMPERATURE CHART FOR REVERSE CYCLE HEAT — HIGH HEAT 47 F (DRYBULB)/43 F (WET BULB) OUTDOOR AIR 15 20 25 30 35 40 52C,P SERIES
WIRING DIAGRAMS Refer to Figures 68-72 for Typical Wiring Schematics. NOTE: Figures 68-72 should not be substituted for the schematic located on control box.
52C,P SERIES TYPICAL THERMOSTAT INTERFACE T’STAT OUTPUT: RC CONTROLER OUTPUT: UNIT OPERATION: ‘G’ — 24 VAC ‘FR’ — LINE VAC FAN ‘G’ — 0 VAC ‘FR’ — 0 VAC ‘Y’ — 24 VAC ‘HR1 & HR2’ — LINE VAC HEATING ‘O’ — 0 VAC ‘RVR’ — LINE VAC ‘W’ — 24 VAC ‘HR1 & HR2’ — LINE VAC HEATING ‘Y’ — 24 VAC ‘CR’ — LINE VAC COOLING ‘O’ — 24 VAC ‘RVR’ — 0 VAC ‘R’ — 24 VAC ‘R’ — 24 VAC OUTPUT POWER TO WALL ‘C’ — COMMON ‘C’ — COMMON THERMOSTAT 1. If ‘W’ is ON, then ‘FR’ is forced ON (regardless of ‘G’) & ‘CR’ is forced OFF. 2.
COMPONENT LEGEND Component Connection (Marked) CAP COMP FM FCS HTR IT NEC OL PLS SLS ST SW — — — — — — — — — — — — Component Connection (Unmarked) Accessory or Optional Wiring To Indicate Common Potential Only Not To Represent Wire Capacitor Compressor Fan Motor Fan Cycle Switch Heater Indoor Thermostat National Electrical Code Overload Primary Limit Switch Secondary Limit Switch Start Thermistor Switch NOTES: 1. Recommended for use on grounded power supply only. 2.
52C,P SERIES COMPONENT LEGEND Component Connection (Marked) Component Connection (Unmarked) Terminal Board Connection Field Splice Field Control Wiring Accessory or Optional Wiring CAP COMP — — To Indicate Common Potential Only Not To Represent Wire Capacitor Compressor FM HTR IFT NEC OL PCBD HR1 HR2 CR FR PLS SLS SSS ST TRANS — — — — — — — — — — — — — — — Fan Motor Heater Indoor Frost Thermostat National Electrical Code Overload Printed Circuit Board Heater Relay Heater Relay Compressor Relay Fan Re
FIGURE 72 — 52PC — TYPICAL WIRING SCHEMATIC FOR STANDARD COOLING ONLY UNITS 45
52C,P SERIES MOST FREQUENT PTAC SERVICE QUESTIONS 1. Can remote wall thermostats be used on standard (AA) models? 2. Which remote thermostats are acceptable for use on 52C,P products? 3. How many 52C,P series units can be controlled by one remote thermostat? 4. What is the vent capacity of the 52C,P products? 5. How do the 52C,P series models handle condensate removal? 6. 7. 8. 9. No, only for use on remote control (RC,RP) models.
ACCESSORIES ACCESSORY Wall Sleeves Exterior Grilles† FORM NUMBER PART NUMBER 52S-48SI WALL-SLEEVE-1PK WALL-SLEEVE-9PK SLEEVE-INSUL-1PK 52S-50SI SLEEVE-STEEL-1PK 52S-49SI* SLEEVE-EXT24-1PK 52C,P-20SI FR-SLEEVE-EXT 52S-59SI 52S-65SI 52C,P-11SI GRILLE-ALU-STAMP GRILLE-PLA-BROWN GRILLE-PLA-BEIGE GRILLE-ALU-CLEAR GRILLE-ALU-WHITE GRILLE-ALU-BRONZ GRILLE-ALU-MBRNZ GRILLE-ALU-BROWN GRILLE-ALU-BEIGE GRILLE-ALU-ALPIN GRILLE-ALU-PEACH GRILLE-ALU-MELON GRILLE-ALU-LGREY GRILLE-ALU-SGREY GRILLE-ALU-RDBRK GRILLE-ALU-
52C,P SERIES 52C PERFORMANCE AND PHYSICAL DATA CATALOG NUMBER COOLING (Btuh) EER ELECTRIC HEAT (Btuh) COP 52CE-207---3 52CE-307---3 7,000/ 6,900 7,000/ 6,900 9,000/ 8,900 9,000/ 8,900 12,000/11,900 12,000/11,900 12,000/11,900 14,500/14,000 14,500/14,000 14,500/14,000 7,000 7,000 8,900 8,900 12,000 12,000 12,000 14,500 14,500 14,500 11.1/11.1 11.1/11.1 10.7/10.7 10.7/10.7 10.1/10.1 10.1/10.1 10.1/10.1 9.4/ 9.5 9.4/ 9.5 9.4/ 9.5 11.1 11.1 10.7 10.7 10.1 10.1 10.1 9.4 9.4 9.
52P PERFORMANCE AND PHYSICAL DATA CATALOG NUMBER COOLING (Btuh) EER ELECTRIC HEAT (Btuh) COP 52PE-207---3 52PE-307---3 7,200/ 7,100 7,200/ 7,100 9,100/ 9,000 9,100/ 9,000 12,100/12,000 12,100/12,000 12,100/12,000 14,500/14,000 14,500/14,000 14,500/14,000 7,200 7,200 9,100 9,100 12,100 12,100 12,100 14,500 14,500 14,500 12.7/12.7 12.7/12.7 11.5/11.5 11.5/11.5 11.1/10.7 11.1/10.7 11.1/10.7 9.4/ 9.5 9.4/ 9.5 9.4/ 9.5 12.7 12.7 11.5 11.5 11.1 11.1 11.1 9.4 9.4 9.
Copyright 2002 Carrier Corporation Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. PC 132 Catalog No. 535-20050 Printed in U.S.A.
