Vertiv Liebert CRV - Table 12.1 Unit diagnostics

PROBLEM POSSIBLE CAUSE CORRECTIVE ACTION
Rack temperature
is too high
Dirty filters Replace filters
Filter clog sensor
failure
Call Vertiv™ technical support.
Incorrect positioning of
remote temperature
sensor(s)
Verify that remote temperature sensors are correctly positioned
Remote temperature
sensor(s) issue
Verify CANbus cable connections and CANbus termination are correct.
Adjust remote sensor mode (max/average) and number of sensors calculated in average.
Contact your local Vertiv™ representative
Chilled water units:
inlet water temperature
is too high
Check cooling water temperature
Refrigerating circuit
charge issue
Contact your local Vertiv™ representative
Cold air short-cycling
issues
Verify unit positioning/room configuration
Verify unit air baffles set-up
Verify cold aisle containment seals (if applicable)
Insufficient room-
cooling capacity
Reduce rack heat load or add cooling units
Chilled water-regulating
valve issue
Contact your local Vertiv™ representative
Unit safety device
tripped
Contact your local Vertiv™ representative
Compressor will not
load
Verify air temperature setpoint and temperature control sensor reading
Verify suction pressure in the service menus, diagnostic service icon with the compressor loaded to
100%. If the suction drops below 109 psi (7.5 bar), the compressor capacity will decrease to help build
suction. Verify suction transducer reading is correct compared with a manifold gauge.
Evaporator Fans
will not modulate
from 100%
Low pressure condition
detected
Verify suction pressure in the service menus, diagnostic service icon with the compressor loaded to
100%. If the suction drops below 109 psi (7.5 bar), the fan speed will increase to help build suction.
Verify suction transducer reading is correct compared with a manifold gauge.
Contact your local Vertiv™ representative
Fan control not properly
set
Refer to the fan-settings descriptions in the "Liebert® iCOM™ User Manual” included with your system
documentation.
Contact your local Vertiv™ representative
Capacity Reduced
due to HP Alarm
(Comp Reduced by
HP)
Condensing pressure
(head pressure) has
exceeded 493 psig (34
bar)
Air-cooled units: Verify that remote condenser fan(s) are running.
Check accuracy of transducer by attaching a manifold gauge to discharge side of compressor.
Compare gauge reading to what is shown in Service Menus, Diagnostic service mode.
Water/glycol units: Check cooling water supply
Water/glycol units: Check cooling water temp
Contact Vertiv™.
Table 12.1 Unit diagnostics
Vertiv | Liebert CRV Installer/User Guide | 128