REMKO RXT xxx DC - Manual (Page 39)

3. Fault code E3: communication error on main board
of the outdoor component
Replace
main board
Does LED1 flash on the
outdoor component
main board?
Establish a proper
connection
Is the electrical
connection between
the power board and
CN4 on the main board
OK?
No
No
Yes
Disconnect the
electrical connection
between the power
board and CN4 on the
main board.
Is there a measurement
of 5V on power board
CN1 between the 3th
and 4th pins?
Replace
main board Yes
Yes
Is the connection between
the IPM module (positive
terminal) and CN12 on
the power board OK?
No
Establish a proper
connection
Is the connection between
the IPM module (negative
terminal) and CN13 on
the power board OK?
Is there a measurement
of 277-345V between
CN12 and CN13 on
the power board?
Yes
Replace
IPM module
No Replace power board
No Establish a proper
connection
Yes
No
Yes
4. Fault code E4: fault on outside temperature
sensor T4 or condenser sensor T3
Connect condenser
sensor properly
Is the condenser
sensor properly
connected?
Replace
sensor
Measure the resistance
of the sensor. (Table 1,
P92-94)
Resistance OK?
No
Yes
Is the outside
temperature sensor
properly connected? Connect the outside
temperature sensor
properly
Yes
Measure the resistance
of the sensor. (Table 1,
P92-94)
Resistance OK?
Replace sensor
Replace
main board
No
Yes
Yes
No
No
5. Fault code E5: compressor overvoltage protection
Replace supply line
Is the supply line
properly connected and
are there 172-265 V
between L1 and N?
Replace
main board
Replace power board
Does the unit work
after the replacement?
No
Yes
No
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