STULZ CyberRow DX Series Installation, Operation & Maintenance Manual
5-3
SYMPTOM
PROBABLE
CAUSE
RECOMMENDATION
Air Flow Too Low
Dirty
air
fi lters. (Reduced airfl ow)
Clean/replace fi lters.
EC Fan(s) Fail to Start
a. Power failure.
Check main voltage power source
input cable.
b. Motor starter protector tripped.
Reset motor starter protector and check
amperage of motor.
c. Control transformer circuit
Check for short circuit or ground fault;
breaker tripped.
if none reset circuit breaker.
d. Condensate overfl ow switch open.
1. Ensure unit is level.
2. Check that condensate pan is draining.
e. Defective contactor.
Repair or replace.
f. No control signal to fan(s).
Check the Control I/O Board for a 0-10
VDC control signal to the fan(s). Refer
to the electric drawing to determine the
correct I/O board terminal numbers. This
must done within 15 seconds of turning
the disconnect switch “On” or the controller
will go into “Air Proving Alarm” mode.
g. EC fan’s internal overheat protection
Determine the cause of the interruption
interrupted fan motor operation.
and correct. Possible causes are:
1. Blocked rotor.
2. Low supply voltage > 5 seconds.
3. Loss of phase > 5 seconds.
After causes 1, 2, and 3 are corrected, the
motor will automatically reset.
After the causes below are corrected,
the fan(s) must be manually reset by
turning off power for 20 seconds:
4. Over temperature of electronics.
5. Over temperature of motor.
Control is Erratic
Wiring improperly connected or broken.
Check wiring against electrical drawing.
Compressor Fails to Start
a. Temperature setpoint too high.
Adjust to desired temperature.
b. Compressor internal overload
Check compressor for short circuit
protector is open.
or ground.
5.2 Troubleshooting
Turn off all power to the unit before conducting any troubleshooting procedures, unless the procedure
specifi cally requires the system to operate. For troubleshooting purposes, the system may be operated with
the doors open by using a pair of channel lock pliers to turn the shaft of the main power disconnect switch
to the “On” position. When the switch is turned on, high voltage will be present inside the cabinet. Exercise
caution to prevent injury. Keep hands, clothing and tools clear of the electrical terminals and rotating
components. Ensure that your footing is stable at all times.
Содержание CyberRow DX CRS-042-G
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