Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 1046

FDC-HKXR
(k) Protection of Power Transistor from Overheat
When the temperature of the power transistor increases to the set temperature, stop the inverter immediately and let is reset
by itself 3 minutes later. If the power transistor is overheated again within 2 hours, turn off 52C, bring it to an abnormal
stop and the inspection displays (Remote controller : E41, indoor unit green LED : Continuous flashing, red LED : OFF,
outdoor unit green LED : Continuous flashing, red LED : 4 times flash) will appear.
(l) Protection of Number of Connected indoor Units
When the number of connected indoor units exceeds the quantities shown in the table below, they will come to an abnormal
stop, and the inspection displays (Remote controller E43, indoor unit green LED : Continuous flashing, red LED : OFF,
outdoor unit green LED : Continuous flashing, red LED : 7 times flash) will appear.
Number of connected units
(m) Frost prevention during cooling
To prevent frost during a cooling operation, check temperature (to be detected with Th
and lower the frequency of indoor unit (opening of expansion valve) when the temperature drops below 3°C.
When the heat exchanger temperature is below 2°C for more than 2 minutes, turn off the thermostat and start a ventilating
operation. If the heat exchanger temperature rises above 16°C after the thermostat is turned off, reset it to a cooling operation.
But this operation shall not be executed for 10 minutes after the thermostat is turned on.
Also when temperatures of standing units have been below 2°C for an hour in succession, turn off the compressor for 3
minutes.
(n) Control of Temperature under Dome
The liquid bypass solenoid valve (SV1) is controlled according to the temperature of the thermistor (Th
fitted to the compressor.
Full Load
Close
55°C
Th C > 65°C SV
O-
Th C < 55°C SV
O-
1044
FDCP2001 type
Open
65°C
open
1
close
1
8 units
) of the indoor unit heat exchanger
I-R
Hot gas bypass
Open
Close
30°C 40°C
Th C > 40°C SV
O-
Th C < 30°C SV
O-
FDCP2501 type
8 units
C) under the dome
O-
open
1
close
1