Vertiv Liebert Drycooler, Installer/User Manual, Page: 55 / 102

8 TROUBLESHOOTING
Symptom Possible Cause Check Or Remedy
Unit will not operate
No main power Check L1, L2 and L3 for rated voltage
Disconnect switch
open Close disconnect switch
Blown fuse or circuit
breaker tripped Check fuses or circuit breaker
Control fuse or circuit
breaker tripped Check for 24VAC. If no voltage, check for short. Replace fuse or
reset circuit breaker.
Improperly wired Check wiring diagram
No output voltage
from transformer Check for 24VAC. If no voltage, check primary voltage.
Unit runs, but motor protector
keeps tripping
Motor protector
defective Replace protector
Motor protector too
small Check amp. draw
Fan or pump motor
has shorted winding Repair motor
Low or unbalanced
voltage Determine reason and correct
Outlet temperature from unit
too high
Low or no coolant flow
See Pump will not operate or no coolant flow on the next page
entry in this table.
Ambient air
temperature higher
than design Correct possible hot air discharge to fans from another source.
Heat load higher than
design Check for misapplication, need larger cooler. Correct possible
additional heat load being added to cooling circuit.
Throttling valve
improperly Reset valve to proper differential pressure.
Liquid squirts from surge tank
fill cap when pump is turned off Air in system Vent all high points, repeat as necessary. Check liquid level in
surge tank.
Pump suddenly stops pumping
Clogged strainer or
impeller Clean out debris.
Pumping suddenly slows
Clogged impeller,
diffuser or line Clean out debris and use strainer.
Table 8.1 Troubleshooting Symptoms and Checks
8 Troubleshooting
51