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(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
:
, 81°F
20.5
:
, 69°F
Indoor fl uid pipe temperature (TH2)
5
:
, 41°F
45
:
, 113°F
Indoor 2-phase pipe temperature (TH5)
5
:
, 41°F
50
:
, 122°F
Set temperature
25
:
, 77°F
22
:
, 72°F
Outdoor fl uid pipe temperature (TH3)
45
:
, 113°F
5
:
, 41°F
(
w
1)
Outdoor 2-phase pipe temperature (TH6)
50
:
, 122°F
5
:
, 41°F
(
w
1)
Outdoor air temperature (TH7)
35
:
, 95°F
7
:
, 45°F
(
w
1)
Temperature difference code
(intake temperature - set temperature) (
∆
Tj)
5
5
Discharge super heat (SHd)
30˚C, 54˚F
30˚C, 54˚F
(
w
2)
Sub-cool (SC)
5˚C, 9˚F
5˚C, 9˚F
(
w
2)
w
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.
w
2: If one thermistor is set to open/short, the values of 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
:
, 113°F
5
:
, 41°F
TH6
Ta
Tb
Regard normal fi gure as effective data.
TH32
Tc
Td
Regard normal fi gure as effective data.
TH5
5
:
, 41°F
50
:
, 122°F
TH2
5
:
, 41°F
45
:
, 113°F
Discharge superheat (SHd)
Cooling = TH32 - TH6 = Tc - Ta
Heating = TH32 - TH5 = Td - (50
:
or 122°F)
Degree of subcooling (SC)
Cooling = TH6 - TH3 = Ta - (45
:
or 113°F)
Heating = TH5 - TH2 = 50
:
- 45
:
= 5 ˚C.
or
= 122°F - 113°F = 9˚F
OCH512