MITSUBISHI ELECTRIC P500YMF-C - Manual (Page 93)

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Note 1 :
• Symptoms of incorrect i.e, reverse connection of PS
1
and PS
3
to BC controller board
Note 2 :
• Check using LED monitor display switch (outdoor MAIN board SW1)
Note 3 :
• Check CNP1 (liquid measurement) and CMP3 (intermediate) connectors on BC controller board for disconnection or
looseness.
Note 4 :
• With the sensor of the applicable connector removed from the board, use the LED monitor display switch (Note 1) to
check the pressure value.
Pressure Sensor Replacement Precaution
Symptom
Cooling-only Cooling-principal Heating-only Heating-principal
Normal
Insufficient
cooling.
SC11 large
SC16 small
PHM < 0
SC11 large
SC16 small
PHM < 0
Warm indoor
SC small. When
SV opens some
noise produced.
SC11 small
SC16 small
PHM < 0
Insufficient heating
Warm indoor SC small
When SV opens some
noise produced.
Measured Data
High pressure of
outdoor
Low pressure satura-
tion temperature
Low pressure of
outdoor
BC controller pressure
(liquid measurement)
(intermediate)
Signal
HPS
TH2
LPS
PS1
PS3
SW1 Setting Remarks
See converter.
See converter.
See converter.
Convert saturation
temperature to
desired pressure
using converter.
1
ON
2 3 4 5 6 7 8 9 10
1
ON
2 3 4 5 6 7 8 9 10
1
ON
2 3 4 5 6 7 8 9 10
1
ON
2 3 4 5 6 7 8 9 10
1
ON
2 3 4 5 6 7 8 9 10
(Pressure sensor output voltage)