Carrier CAS072 Installation, Start-up And Service Instructions Manual

CAS-072-153-01SI Rev. A Specifications subject to change without notice. 33Table 25 — TroubleshootingPROBLEM SOLUTIONCOMPRESSOR DOES NOT RUNContactor Open1. Power off. 1. Restore power.2. Fuses blown in field power circuit. 2. After finding cause and correcting, replace with correct size fuse.3. No control power. 3. Check control transformer primary connections and circuit breaker.4. Thermostat circuit open. 4. Check thermostat setting.5. Safety device lockout circuit active. 5. Reset lockout circuit.6. Low-pressure switch open. 6. Check for refrigerant undercharge, obstruction of indoor airflow. Make sure liquidline solenoid valve(s) is open.7. High-pressure switch open. 7. Check for refrigerant overcharge, obstruction of outdoor airflow, air in system. Besure outdoor fans are operating correctly8. Compressor over-temperature switch open. 8. Check for open condition. Allow for reset. Replace compressor if necessary9. Loose electrical connections. 9. Tighten all connections.10. Compressor stuck. 10. See compressor service literature.11. Fan fault or shutdown condition in fan coil unit active,preventing thermostat signals passing from fan coil unit toCAS.11. Reset fan limit switch (F*X) or address fault in VFD (F*S/H).Contactor Closed1. Compressor leads loose. 1. Check connections.2. Motor windings open. 2. See compressor service literature.3. Single phasing. 3. Check for blown fuse. Check for loose connection at compressor terminal.COMPRESSOR STOPS ON HIGH-PRESSURE SWITCHOutdoor Fan On1. High-pressure switch faulty. 1. Replace switch.2. Reversed fan rotation. 2. Confirm rotation, correct if necessary.3. Airflow restricted. 3. Remove obstruction.4. Air recirculating. 4. Clear airflow area.5. Non-condensables in system. 5. Recover refrigerant and recharge as required.6. Refrigerant overcharge. 6. Recover refrigerant as required.7. Line voltage incorrect. 7. Consult power company.8. Refrigerant system restrictions. 8. Check or replace filter drier, expansion valve, etc.Outdoor Fan OffNote: On CAS121/151 and CAS123/153 systems, Outdoor Fan1 will be off in cooling mode below 55 ±1.5°F outdoortemperature.1. Fan slips on shaft. 1. Tighten fan hub setscrews.2. Motor not running. 2. Check power and capacitor.3. Motor bearings stuck. 3. Replace bearings.4. Motor overload open. 4. Check overload rating. Check for fan blade obstruction.5. Motor burned out. 5. Replace motor.COMPRESSOR CYCLES ON LOW-PRESSURE SWITCHIndoor-Air Fan Running1. Liquid line solenoid valve(s) fails to open. 1. Check liquid line solenoid valve(s) for proper operation. Replace if necessary.2. Filter drier plugged. 2. Replace filter drier.3. Expansion valve power head defective. 3. Replace power head.4. Low refrigerant charge. 4. Add charge. Check low-pressure switch setting.Airflow Restricted1. Coil iced up. 1. Check refrigerant charge.2. Coil dirty. 2. Clean coil fins.3. Air filters dirty. 3. Clean or replace filters.4. Dampers closed. 4. Check damper operation and position.Indoor-Air Fan Stopped1. Electrical connections loose. 1. Tighten all connections2. Fan relay defective. 2. Replace relay.3. Motor overload open. 3. Power supply.4. Motor defective. 4. Replace motor.5. Fan belt broken or slipping. 5. Replace or tighten belt.6. Fan fault or shutdown condition in fan coil unit active. 6. Reset fan limit switch (F*X) or address fault in VFD (F*S/H).