KRSD series
Page 36
The air compressor controller provides protection functions for short-circuit, blocking, phase fault,
overload and phase imbalance.
Fault
Fault Display
Probable Cause
Short circuit
“MOTOR/FAN
OVERLOAD”
Short circuit or rated current has not been set
correctly.
Blocked
“MOTOR/FAN BLOCK”
Too much load, bearing wear or other
mechanical problem.
Overload
“MOTOR/FAN
OVERLOAD”
Too much load, bearing wear or other
mechanical problem.
Phase loss
“MOTOR/FAN LACK
PHASE”
Power supply, contactor or motor phase loss.
Unbalance
“MOTOR/FAN
UNBLANCE”
Poor contact of contactor, internal open-loop of
motor.
2. Discharge air high temperature protection.
When the Air discharge temperature is higher than the set temperature, the controller will stop
the compressor. The display will show
“DISC T HIGHT
”.
3. Anti-reversing protection.
When the three-phase power supply sequence connected to the air compressor is not the same of
that set for the controller, the fault is displayed as “
PHASE WRONG1
”, as a result, the controller
cannot start the compressor. Change any arbitrary two-phase power lines and check the rotation
of the motor.
4. Overpressure protection.
When the discharge air pressure is higher than the set pressure, the controller will stop the
compressor. The fault is displayed as “
HIGH P
”.
5. Sensor malfunction protection.
When pressure sensor or temperature sensor is disconnected, the controller cannot start the
compressor. The fault is displayed as “
**SENSOR FAULT
”.
6. Open phase protection.
When an open phase is detected, the controller cannot start the compressor. The fault is displayed
as “
PHASE WRONG2
”.
