Friedrich FSHW091, Service And Parts Manual

Page: 134 / 171

134 PB
TROUBLESHOOTING
9-24k PM protection, phase current overcurrent
(the control board as below indicates the control board of outdoor unit) H5/P5
Mainly detect:
(1) Compressor COMP terminal (2) voltage of power supply (3) compressor
(4) Refrigerant-charging volume (5) air outlet and air inlet of outdoor/indoor unit
Troubleshooting:
Turn on the unit
after energization
Whether IPM
protection occurs after the unit has
operated for a while?
Measure the voltage
between terminal L
and terminal N with
AC volmeter
Whether
the voltage between
terminal L and terminal N of XT is
within 210AVC~
250VAC?
1. Whether the heat exchangers of indoor unit and outdoor unit are
dirty? Whether the radiation is affected because the unit is
covered by the objects?
2. When indoor fan and outdoor unit are operate normally?
3. Whether the system pressure is too high?
4. Whether the pressure is because there's too much refrigerant?
Check the power
supply voltage and
make the power voltage
resume to the range
of 210VAC~250VAC
Correctly connect the wires of
compressor according to the
electric wiring diagram, and
then turn on the unit
Check whether wires
of compressor (UVW) are connected
correctly
Check the connection
between the control board
and the compressor by
referring to the electric
wiring diagram
Measure the resistance value
among three terminals (UVW)
of compressor with a resistance
measuring meter.
Whether the
resistance value of three terminals
are almost the same.
Replace the
compressor
Whether the unit
can operate normally?
Whether there's
abnormal phenomenons
described as above?
End
Replace control
board
Measure the resistance
between three terminals (UVW)
of compressor and the copper pipe
with resistance measuring meter
Whether the
resistance value is more than
500ohm?
Correct it one by one
according to the Service
Manual, and then turn on
the unit.