Gree GUD50PS/A-T - Pd‖ Sensor Connection Protection; PL‖ Bus Low-Voltage Protection

GREE U-Match 5 SERIES UNIT SERVICE MANUAL
69
3.4.33 ―Pd‖ Sensor Connection Protection
Error display: ODU mainboard, IDU wired controller and IDU receive light board will display Pd
Error judgment condition and method:
Sample the AD value of sensor through sensor detecting circuit and judge the range of AD value, If the sampling AD value
exceeds upper limit and lower limit in 5 seconds continuously, report the error.
Possible reason:
■Poor contact between sensor and terminal in mainboard interface
■sensor is abnormal
■Detecting circuit is abnormal
Troubleshooting：
Pd Sensor connection
protection
Correctly insert the sensor
on the needle stand
Check if the discharge sensor on
mainboard is inserted on the needle stand
correctly
YES
Disconnect the sensor and
measure if its resistance is
normal
NO
NO
Replace the sensor
YES
Replace the outdoor
mainboard
3.4.34 ―PL‖ Bus Low-Voltage Protection
Error display: ODU mainboard, IDU wired control and IDU receiver light board will display PL
Error judgment condition and method:
When compressor is running and there is no other malfunction, if busbar voltage is lower than the set value
for low voltage protection, then it can be judged that bus low-voltage protection occurs. System will shut down for
protection.
Possible reason:
■Voltage of power grid is abnormal.
■Drive board busbar voltage sampling circuit element is damaged or drive board busbar voltage sampling AD
terminal is abnormal.