Manitowoc QF0400 Technician's Handbook page 190

Relay Operation Check
1. Disconnect wires from relay terminals.
2. Verify the contacts are closed.
Measure the resistance between terminals 1 and
2. No continuity indicates open contacts. Replace
the relay.
3. Check the relay coil.
Measure the resistance between terminals 2 and
5. No resistance indicates an open coil. Replace
the relay.
4. Move toggle switch to the ICE position.
5. The compressor start winding should energize for
less than 1 second. Continued high amperage
draw could indicate:
• Low incoming power supply.
(Check voltage at compressor start-up when load
is greatest.)
• Defective relay.
• Defective capacitor.
• Defective compressor.
6. Verify voltage and replace all start components.
7. If all of the previous tests are satisfactory and the
compressor will not operate or continue to
operate, replace the compressor.
190 Part Number 80-1230-9 10/10