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Phase Sequencer
The unit with Scroll Compressor can only rotate in one direction. For this reason, a protective device (phase
protector) is tted to prevent incorrect wiring of the electrical phases. When the three phases are not
connected correctly, the phase protector operates, and the unit will not start.
This device is located in the control box of the outdoor unit.
The following table shows the LED indicator light for phase protector under normal operation and fault
conditions.
LED
Description
PW
(Red)
P_S
(Yellow)
P_T
(Yellow)
Actions
Normal operation
-
Reverse phase
missing (local)
Switch off the unit. Check the 3
phase wiring.
R (main power)
phase missing (local)
Switch off the unit. Check the 3
phase wiring.
R phase missing
(export)
Switch off the unit. Check the 3
phase wiring.
T phase missing
Switch off the unit. Check the 3
phase wiring.
S phase missing
Switch off the unit. Check the 3
phase wiring.
Reverse phase
Switch off the unit. Check the 3
phase wiring.
Overheat
High discharge temperature. Check
the refrigerant system.
High pressure
High discharge temperature. Check
the refrigerant system.
Low pressure
Low discharge temperature. Check
the refrigerant system.
Discharge sensor
missing
Switch off the unit. Plug in sensor.
ON
OFF
Fast Blink
Notes:
1. The relay will not cut off if sensor missing fault happened.
2. All errors can only be recovered by manual reset.