User Guide

LED Status (Cont.) Troubleshooting Procedure
Yellow LED is dim and flickering.
Use these steps to resolve the problem:
1. Check the power source.
2. Confirm that the compressor is operating at sufficient pressure and without
excessive pressure fluctuations.
3. Check the wiring harness for loose connections.
4. If the oil pressure is sufficient, the cable connections are good, and the yellow
LED still flickers, replace the P400 switch.
Control does not lock out the
compressor when lube oil
pressure is low.
Use these steps to resolve the problem:
1. Press the test button.
a. If the P545 control does not lock out in 8 seconds or less, replace the
control.
b. If the P545 control locks out properly, go to Step 2.
2. Disconnect the wiring harness from the P545 control. Press the Reset button.
3. If the compressor starts and runs through the time delay (yellow and green LEDs
lit) and then locks out, check the wiring harness for shorted condition. If the
wiring harness tests okay, replace the P400 switch.
Control does not respond to
R310AD switch. (Control locks
out the compressor after
compressor shutdown. Red LED
is lit.)
Make sure that the anti-short cycle delay is not set at 0 seconds.
Control does not respond to
R310AD switch. (Indicated by the
green LED turning on for
approximately 4 seconds,
followed by the yellow LED
turning on for the duration of the
selected anti-short cycle time
delay. This process repeats
indefinitely.)
Use these steps to resolve the problem:
1. Check that resistor R39 has been cut and discarded.
2. Check the R310AD switch; replace if necessary.
Contactor energizes for 3 or
4 seconds. It remains off for the
duration of the anti-short cycle
time delay, and then repeats
(compressor is unable to start
during the 3 to 4 second period).
Insufficient current to the R310AD switch is the most likely cause of this condition.
Use these steps to resolve the problem:
1. Check compressor for internal overloads.
2. Check the compressor wiring.
3. Check compressor’s contactor.
4. Check compressor for general failure.
10 P545 Series Electronic Lube Oil Control Product/Technical Bulletin