Evaporator Motor Overheated

1. Check Evaporator Fan Blades for Free Operation - Visually inspect evaporator fan for any foreign material or damage or anything that will prevent the blade and motor from turning freely Blower wheel must be in good condition. No sticks or other material obstructing its movement. No ice build-up preventing blade rotation. 2. Check for 12 VDC at PM-6, PM-33, and 1EVCON-A1 a. If 12VDC, then alarm should have cleared itself. b. If no power (0VDC), then continue with steps below. 3. Check IPC Circuit a. Use Component Test mode to energize Evaporator Motor Contactor circuit. (Refer to Section 5.2.4.) Output will come on. b. Unplug the connector to the evaporator fan motor and check voltage on IP-EVM (white) wire. Check voltage at pin 5, should read 3 VDC. No voltage indicates an open from pin 5 to PM-33. Check voltage at pin 4, should read 12VDC. No voltage indicates open from pin 4 to PM-6. c. Test continuity through IPC. Should be 0 Ohms. If the evaporator fan motor is extremely warm, allow it to cool off, then recheck IPC continuity. 4. Check Evaporator Fan Motor Contactor a. Inspect the wire connections to the contactor. (See wiring schematic Section 10.2.) Check for signs of overheating of the contactor. Wiring is routed correctly to the contactor. b. Check tightness of the contactor wire connections. Tighten with screwdriver and check for discoloration of wires. 5. Perform Pretrip - Clear Active Alarm list, then run Pretrip and check for any new alarms. Any active alarms must be corrected and cleared before proceeding. 6. Check Evaporator Fan Motor - Disconnect power plug at motor Test IP circuit for continuity using ohmmeter. If IP remains open after a 30 minute cool down period, and motor feels cool to the touch, remove and replace motor. Refer to Section 8.9.9. • If closed, then an intermittent IP circuit is suspect. Check phase to phase and phase to ground for short or open circuits. Refer to Section 2.10 for correct electrical values. • If motor tests good, check the DC IP circuit to microprocessor. 7. Check Motor Operation - Turn the unit ON. Check current on each phase (must be less than shown on Section 2.10). Check voltage on each phase (must be at within limits shown in Section 2.10.)