Sinclair SCV-1400EB, Service Manual

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113
Procedure
PE
Taf temperature sensor connection on main
PCB is loose
1
Yes Ensure the sensor is connected properly
No
Taf temperature sensor has short-circuited
or failed
2
Yes
Replace the sensor
No
Insufficient refrigerant caused by
refrigerant leakage 3
Yes
Add refrigerant or inspect the system for
leaks
No
The low pressure side is blocked, caused by
crushed or bent pipe, blocked EXV, or dirty
filter
4
Yes
Inspect the system and fix the error. If the
filter is blocked by ice, the piping should be
cleaned
No
The air side heat exchanger heat exchange
is poor in heating mode 5
Yes
Inspect the refrigerant system and fix the
error
No
The water flow rate is not sufficient in
cooling mode 6
Yes
Inspect the water system and fix the error
No
Replace main PCB
Notes:
1. For SCV-750EB and SCV-1400EB, Water side heat exchanger anti-freezing temperature sensor (Taf2) connection are ports CN45 on the main PCB (labeled
21 in Part 4, 2.2.1 Main PCB component). For SCV-900EB and SCV-1800EB, Water side heat exchanger anti-freezing temperature sensor (Taf, include Taf1
and Taf2) connection are ports CN31 and CN69 on the main PCB (labeled 31,32 in Part 4, 2.2.1 Main PCB component);
2. Measure sensor resistance. If the resistance is too low, the sensor has short-circuited. If the resistance is not consistent with the sensor’s resistance
characteristics table, the sensor has failed. Refer to Part 4, 6.1 “Temperature Sensor Resistance Characteristics”;
3. To check for insufficient refrigerant: an insufficiency of refrigerant causes compressor discharge temperature to be higher than normal, discharge and
suction pressures to be lower than normal and compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. These
issues disappear once sufficient refrigerant has been charged into the system;
4. A low pressure side blockage causes compressor discharge temperature to be higher than normal, suction pressure to be lower than normal and
compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. For normal system parameters;
5. Check air side heat exchanger, fan(s) and air outlets for dirt/blockages;
6. Check water side heat exchanger, water piping, circulator pumps and water flow switch for dirt/blockages.