Vertiv Liebert Mini-Mate2 - Troubleshooting; Troubleshooting Guide

13 TROUBLESHOOTING
Symptom
Possible
Cause
Check Or Remedy
Unit will not start
No power to
unit
Check voltage at input terminal block.
Control
voltage circuit
breaker (at
transformer)
open
Locate short and reset circuit breaker.
Float switch
relay closed
because of
high water in
the
condensate
pan
Has rubber band been removed from float switch? Check drain and line. Access through left panel. Power must
be cycled at the disconnect to reset.
Jumper not in
place
Check terminal TB1-4 and TB1-5 for jumper or N/C contact. Check pins 1-8 and 1-9 for jumper or N/C high
temperature sensor contact. Check pins 5-4 and 5-5 for jumper or N/C smoke sensor contact.
No cooling
Cooling not
displayed at
the control
panel
Adjust TEMP control set point and sensitivity to require cooling.
Short cycle
prevention
control
Control software delays compressor 3 minutes cooling, from stop to start
Compressor
contactor not
pulling in
Check for 24 VAC ± 2 VAC at terminals P4-8 and P4-4. If voltage, check contactor. If no voltage at P4-8 and P4-
4, check at terminals P2-3 and P2-8. If voltage, check freeze stat.
Compressor
high head
pressure
See below for cause.
Plugged
filter/dryer
Replace filter/dryer
Low
refrigerant
charge
Check pressure gauges. At low ambient temperatures, proper refrigerant charge is very important on units with
Lee-Temp receivers.
Compressor
high head
pressure
Insufficient air
flow across
condenser coil
Remove debris from coil and air inlets.
Water/Glycol
Cooled only:
No fluid
flowing
through
condenser
Check fluid supply to regulating valve. Adjust valve if necessary.
Condenser fan
not operating
Check fan operation.
Table 13.1 Troubleshooting
Vertiv | Liebert Mini-Mate2—5 ton User Manual| 87