66
OCH708
(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
Operation mode
Remarks
COOL
HEAT
Intake temperature (TH1)
27°C
20.5°C
-
Indoor liquid pipe temperature (TH2)
5°C
45°C
-
Indoor 2-phase pipe temperature (TH5)
5°C
50°C
-
Set temperature
25°C
22°C
-
Outdoor liquid pipe temperature (TH3)
45°C
5°C
*1
Outdoor discharge pipe temperature (TH4)
80°C
80°C
*1
Outdoor comp. surface temperature (TH32/TH33)
Outdoor 2-phase pipe temperature (TH6)
50°C
5°C
*1
Outdoor ambient temperature (TH7)
35°C
7°C
*1
Temperature difference code
(room temperature - set temperature) (∆Tj)
5
5
-
Discharge superheat (SHd)
30°C
30°C
*2
Sub-cool (SC)
5°C
5°C
*2
*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.
Thermistor
COOL
HEAT
TH3
45°C
5°C
TH6
Ta
Tb
Regard normal figure as effective data.
TH4/TH32
Tc
Td
Regard normal figure as effective data.
TH5
5°C
50°C
TH2
5°C
45°C
Discharge superheat (SHd)
Cooling = TH4 (or TH32/TH33) − TH6 = Tc − Ta
Heating = TH4 (or TH32/TH33) − TH5 = Td − 50
Degree of subcooling (SC)
Cooling = TH6 − TH3 = Ta − 45
Heating = TH5 − TH2 = 50 − 45 = 5°C
