Mitsubishi Electric PUZ-ZM60VHA2, Service Manual

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67
OCH771
(5) Operation data during emergency operation
During emergency operation, no communication is performed with the indoor unit, so the data items needed for operation
are set to the following values:
Operation data
Intake temperature (TH1)
Indoor pipe temperature (TH2)
Indoor 2-phase pipe temperature (TH5)
Set temperature
Outdoor liquid pipe temperature (TH3)
Outdoor discharge pipe temperature (TH4)
Outdoor comp. surface temperature (TH33)
Outdoor 2-phase pipe temperature (TH6)
Outdoor ambient temperature (TH7)
Temperature difference code
(room temperature - set temperature) (∆Tj)
Discharge superheat (SHd)
Sub-cool (SC)
Operation mode
COOL
27
°C
5
°C
5
°C
25
°C
45
°C
80
°C
50
°C
35
°C
5
30
°C
5
°C
HEAT
20.5
°C
45
°C
50
°C
22
°C
5
°C
80
°C
5
°C
7
°C
5
30
°C
5
°C
*
1
*
1
*
1
*
1
*
2
*
2
Remarks
*
1
If the thermistor temperature data is normal (not open/short), that data is loaded into the control as valid data.
When the unit enters emergency operation and TH values are mismatched, set the thermistors to open/short.
And the unit runs emergency operation with the values listed above.
*
2
If one thermistor is set to open/short, the values for SHd/SC will be different from the list above.
[Example] When liquid temperature thermistor (TH3) has an open or short circuit.
COOL
45°C
Ta
Tc
5°C
5°C
HEAT
5°C
Tb
Td
50°C
45°C
Thermistor
TH3
TH6
TH4/TH33
TH5
TH2
Regard normal figure as effective data.
Regard normal figure as effective data.
Discharge superheat (SHd)
Cooling = TH4(or TH33) − TH6 = Tc − Ta
Heating = TH4(or TH33) − TH5 = Td − 50
Degree of subcooling (SC)
Cooling = TH6 − TH3 = Ta − 45
Heating = TH5 − TH2 = 50 − 45 = 5°C
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