Filter
Top Products
63
(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 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:, 81˚F
5:, 41˚F
5:, 41˚F
25:, 77˚F
45:, 113˚F
50:, 122˚F
35:, 95˚F
5
30degC, 54degF
5degC, 9degF
HEAT
20.5:, 69˚F
45:, 113˚F
50:, 122˚F
22:, 72˚F
5:, 41˚F
5:, 41˚F
7:, 45˚F
5
30degC, 54degF
5degC, 9degF
(w1)
(w1)
(w1)
(w2)
(w2)
Remarks
w1: 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.
w2: If one thermistor is set to open/short, the values of SHd/SC will be different from the list abve.
[Example] When liquid temperature thermistor (TH3) has an open or short circuit.
COOL
45:, 113˚F
Ta
Tc
5:, 41˚F
5:, 41˚F
HEAT
5:, 41˚F
Tb
Td
50:, 122˚F
45:, 113˚F
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: or 122˚F)
Degree of subcooling (SC)
Cooling = TH6 - TH3 = Ta - (45: or 113˚F)
Heating = TH5 - TH2 = 50: - 45: = 5 degC.
or
= 122˚F - 113˚F = 9degF
OCH429--3.qxp 07.11.20 9:19 AM Page 63