Mitsubishi Electric PUMY-P100VHMB Service Manual page 44

Display
Abnormal point and detecting method
1501
Refrigerant shortage
When the conditions of below detecting
mode or are satisfied during the
compressor operation.
<Detecting mode >
When the below conditions are satisfied
completely.
1. Compressor is operating in HEAT
mode.
2. Discharge super heat is 80
3. Difference of outer temperature
thermistor (TH7) and outdoor piping
temp. thermistor (TH3) applies to the
formula of (TH7-TH3)<5 .
4. High-pressure sensor is below about
2.04MPa.
<Detecting mode >
When the below conditions are satisfied
completely.
1. Compressor is operating.
2. When cooling, discharge superheat is 80
or more.
When heating, discharge superheat is 90
or more.
High pressure sensor is below about 2.32MPa.
2500
Water leakage
1. Suspensive Abnormality when float switch
(Float
detects to be in the water and drain pump
switch
turns on and off except during cooling or dry
model)
mode.
2. Abnormal when detecting that the drain
pump turns on and off again within 1 hour
after the detection of water leakage
suspensive abnormality, and repeats the
detection twice. <2500> is displayed.
3. The unit continues to detect abnormality
while turned off.
4. To release water leakage suspensive
abnormality
· When not detecting that the drain pump
turns off and on within 1 hour after
detecting suspensive abnormality.
· When turning to cooling operation or dry
operation.
· Detected that [liquid pipe temperature –
room temperature] -10deg[-18°F]
Operation mode: When drain pump turns on as float switch detects to be in the water except during cooling/dry mode
Drain pump ON
OFF
Float switch ON
OFF
Gas leakage, Gas shortage
When heating operation, refrigerant
shortage feeling operation (When
heating, airflow or thermo OFF are
mixed-operation, it cause a refrigerant
shortage operation.)
Ball valve performance failure
(not fully opened.)
Error detection of discharge super heat
or more. 1) High-pressure sensor defective
2) Discharge temperature thermistor
defective
3) Thermistor input circuit defective and
high-pressure sensor defective
in multi controller board
Error detection of TH7/TH3
1) Thermistor defective
2) Thermistor input circuit defective in
multi controller board
Defective drain
Clogged drain pump
Clogged drain pipe
Adverse flow of drain in other units
Defective moving part of float switch
Foreign matter on the moving
part of float switch(ex. sludge etc.)
Defective float switch
6 min.
15 sec. 15 sec.
In the water In the air
Water leakage suspensive abnormality
Within 1 hour
Causes
1) Check the ball valve is fully opened.
2) Check the resistance of discharge
3) According to "Outdoor unit functions",
1) Check the resistance of thermistor.
2) According to "Outdoor unit functions",
3) According to "Outdoor unit functions",
6 min.
15 sec. 15 sec.
In the water In the air
Within 1 hour
44
Check points
Check the refrigerant amount.
Check the operation condition and
refrigerant amount.
Check the ball valve is fully opened.
temperature thermistor.
set the SW2 and check the high-
pressure sensor level.
According to "Outdoor unit functions",
check the discharge temp. thermistor
level.
When the high-pressure sensor and
discharge temp. thermistor are normal,
if the above mentioned detecting
pressure level and temp. are very
different from the actual pressure and
temp., replace the multi controller board.
check the outdoor pipe temp. thermistor
level.
check the outer temp. thermistor level.
Check the drain function.
Check moving part of float switch.
Check the value of resistance with the
float switch ON/OFF.
15 sec.
In the water
Water leakage abnormality