CHUNLAN FRD23 - Unit Control Objectives

Troubleshooting
- 103 -
A. Unit control objectives
a. Indoor fans (2 sets, 3-speed)
b. Outdoor fans (2 sets, 1-speed)
c. Compressor
d. Reversing valve
B. Troubleshooting
Failure Phenomena Failure analysis
HV switch
protection
Wire controller displays E0, only
put it to operation after re
-powerup
HV switch shall be ON and card connection shall
have good contact;
Check for bad contact at indoor/outdoor
connecting cable card
3 occurrences of
antifreeze protection
When 3 consecutive antifreeze
protection signals are received in
1 hour, AC unit stops and wire
controller displays E1, only put it
to operation after re -powerup
Check for normal cooling system;
Check for drifting of indoor pipe temperature
sensor resistance
ID ambient temp
probe broken wire
(short circuit)
Wire controller displays E2, only
put it to operation after re
-powerup
First check for bad contact in indoor ambient
temperature sensor connection;
Check for broken wire or short circuit of sensor
ID pipe temp probe
b
roken wire (short
circuit)
Wire controller displays E3, only
put it to operation after re
-powerup
First check for bad contact in indoor pipe temperature
sensor connection;
Check for broken wire or short circuit of sensor
OD pipe temp probe
b
roken wire (short
circuit)
Wire controller displays E4, only
put it to operation after re
-powerup
First check for bad contact in outdoor pipe
temperature sensor connection;
Check for broken wire or short circuit of sensor
Communication
failure
In case of communication failure
between main control board and
wire controller, wire controller
displays E5, only put it to
operation after re -powerup
Check for reliable welding at main control board
CN6 and wire controller CN1 needle seat, reliable
connection of corresponding cards, and broken
wire or short circuit of communication line;
Check for DC12V input at wire controller, DC5V
output at main control board 7805-3 pin, and
DC5V at wire controller RG1-3;
Check for normal voltage at main control board
2003 driving block;
Check for normal voltage at crystal oscillator pin
of main control board and wire controller;
Check for normal input/output voltages of main
control board and wire controller