Carrier VECTOR 1550 Series Operation & Service Manual

62-61753-217-45AlarmNO. Steps ALARM / CAUSE CORRECTIVE ACTION76 CONDENSER MOTOR OVERHEATED TRIGGER-ON: One or both of the condenser fan motor Internal Protectors (IP-CDM1 or 2) circuit isopen. UNIT CONTROL: Engine operation: engine and unit shutdown and alarm.Standby operation: refrigeration system shutdown and alarm with PSCONstill energized. RESET CONDITION: Auto Reset when motor overload input is within limits, or change to engine op-eration, or alarm may be manually reset via keypad or by turning the unit off, then back on again.NOTE: Follow the steps below until a problem is found. Once a repair or correction has been made, the activealarm should clear itself (refer to reset condition above). Operate the unit through the appropriate modes to see ifany active alarm occurs. Continue with the steps below as necessary.1 Check Condenser Fan Blades for Free Operationa. Visually inspect condenser fanblades for any foreign material ordamage or anything that will pre-vent the blade and motor fromturning freelyFan blade must be in good condition.No material obstructing movementNo ice build-up preventing blade rotation.2 Check For Power At 4MP2a. If 12VDC. Alarm should have cleared itself.b. If no power (0VDC.) Continue with step 2 below.3 Check IPC circuita. Check MPQC9. There should be 12 VDC from MPQC9 to Ground.b. Use Component Test Mode to testactual current draw of the circuit.(Refer to Section 5.1.2.)Component FET or board LED (refer to Table 5-1)must be illuminated.View current draw in Data List.Refer to Section 2.12 for normal current values.c. Unplug the connector to condenserfan motor 1 (CDM1) and checkvoltage on pins 4-5 in the engineharness connector.12 VDC between pin 4 and pin 5 indicates the opencircuit is in the IP for CDM1.d. Test continuity through CDM1 IP atpins 4-5 in the fan motor harnessconnector.Should be 0 Ohms. If condenser fan motor 1 is ex-tremely warm, allow it to cool off, then recheck IP con-tinuity.e. Test continuity through IPC. Should be 0 Ohms. If either condenser fan motor isextremely warm, allow it to cool off, then recheck IPCcontinuity.f. Test IP circuit from condenser fanmotor wires to microprocessor.12 VDC at 4MP2.4 Check Condenser Fan Motor Contactora. Inspect the wire connections to thecontactor.No signs of overheating of the contactor. Wiring isrouted correctly to the contactor.b. Check tightness of the contactorwire connections.Tighten with screwdriver and check for discoloration ofwires.5 Perform Pretripa. Clear Active Alarm list, then runPretrip & check for any newalarms.Any active alarms must be corrected and cleared be-fore proceeding.Additional steps on the next page.