64
(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 fluid pipe temperature (TH2)
Indoor 2-phase pipe temperature (TH5)
Set temperature
Outdoor fluid pipe temperature (TH3)
Outdoor discharge pipe temperature (TH4)
Outdoor 2-phase pipe temperature (TH6)
Outdoor air temperature (TH7)
Temperature difference code (intake temperature - set temperature) (
∆
Tj)
Discharge super heat (SHd)
Sub-cool (SC)
Operation mode
COOL
27
:
5
:
5
:
25
:
45
:
80
:
50
:
35
:
5
30deg
5deg
HEAT
20.5
:
45
:
50
:
22
:
5
:
80
:
5
:
7
:
5
30deg
5deg
(
w
1)
(
w
1)
(
w
1)
(
w
1)
(
w
2)
(
w
2)
Remarks
w
1: If the thermistor temperature data is normal (not open/short), that data is loaded into the control as valid data.
If the unit enters emergency operation because TH values have become mismatched, setting the thermistors
to open/short corrects the settings.
w
2: If one thermistor is set to open/short, the values for each will be different.
[Example] When liquid temperature thermistor (TH3) has an open or short circuit.
COOL
45
:
Ta
Tc
5
:
5
:
HEAT
5
:
Tb
Td
50
:
45
:
Thermistor
TH3
TH6
TH4
TH5
TH2
Regard normal figure as effective data.
Regard normal figure as effective data.
Discharge superheat (SHd)
Cooling = TH4 - TH6 = Tc - Ta
Heating = TH4 - TH5 = Td - 50
Degree of subcooling (SC)
Cooling = TH6- TH3 = Ta -45
Heating = TH5- TH2 = 50 - 45 = 5 deg.
OC374A--3.qxp 06.7.26 5:55 PM Page 64
