Nobu NBFS-48IDU, Service Manual

Page: 36 / 42

the sensor and the detection circuit are
abnormal.
P7 light 7
low or high voltage
protection
1
、
Check whether the supply voltage is out of
rang from 150 to 270V
2
、
Check the voltage detection circuit of the IPM
base board is abnormal, if it is abnormal, the
IPM base board or the electric control board
should be replaced.
PA light 10
The evaporator coil
high temp. protection
1、
Check whether the condenser of outdoor unit is
too dirty, and it should be cleaned when it is too
dirty.
2、
Check whether it is running at bad condition
long time.
3、
Check whether senor and wire are normal.
PC light 11
The outdoor ambient
high temp. protection
1
、
Check the outdoor ambient temperature is too
high or there is heat source around the outdoor
unit.
2
、
Check whether the sensor and sensor wire are
normal.