Table 4-2. Unit Maintenance Troubleshooting
TEST OT INSPECTED
1. UNIT DOES NOT START IN ANY MODE.
High voltage is used in the operation of this equipment. Death on contact or
severe injury may result if personnel fail to observe safety precautions.
Step 1. Check to see if input power has been disconnected.
Connect input power.
Step 2. Make sure that power is 208/230 volt, 1 phase, 60 Hertz.
Connect correct input power.
Step 3. Check for loose or damaged electrical connectors or wires. See para 4-23.
Tighten or replace connectors, or repair damaged wires. See para 4-23.
Step 5. Test relays for operation and contacts. See para 4-28 through 4-34.
Replace any defective relays. See para 4-28 through 4-34.
2. INDOOR FAN STARTS IN COOL MODE, OUTDOOR FAN DOES NOT START, COMPRESSOR DOES NOT
After power has been connected to unit, a short (30 minute maximum during very cold
weather) warm up period is required. When compressor reaches a safe operating
temperature, it will come on automatically if the thermostat is set for cooling and the
cooling lever is set to about 10 degrees F (5.6 degrees C) below the ambient indoor
Disconnect input power before performing internal electrical troubleshooting.
Voltages used can be deadly.
Step 1 Check for loose or damaged electrical connectors or wires.
Tighten or replace connectors or repair damaged wires. See para 4-23.
Step 2 Listen for operation of compressor.
If not operating, contact Direct Support Maintenance.