Mitsubishi Heavy Industries FDT90VNPWVH Service Manual page 19

(c) Operation check mode
There is no communication with the outdoor unit but it allows performing operation in respective modes by operating
the remote control.
(d) Drain pump test run mode
As the drain pump test run is established, the drain pump only operates and during the operation protective functions by
the microcomputer of indoor unit become ineffective.
(14) Cooling, dehumidifying frost protection
(a) To prevent frosting during cooling mode or dehumidifying mode operation, the thermostat-OFF if the indoor heat
exchanger temperature (detected with Thi-R) drops to 1.0 °C or lower at 4 minutes after the thermostat-ON. If the
indoor unit heat exchanger temperature is 1.0 °C or lower after 5 minutes, the indoor unit is controlled thermostat-OFF.
If it becomes 10°C or higher, the control terminates. When the indoor heat exchanger temperature has become as show,
the indoor unit send outdoor unit the "Anti-frost" signal.
• Frost prevention temperature setting can be selected with the
indoor unit function setting of the wired remote control.
Item
Temperature - Low (Factory default)
Temperature - High
(b) Selection of indoor fan speed
If it enters the frost prevention control during cooling operation (excluding dehumidifying), the indoor fan speed is
switched.
(i) When the indoor return air detection temperature (detected with Thi-A) is C°C or higher and the indoor heat
exchanger temperature (detected with Thi-R) detects the compressor frequency drop start temperature A°C+1°C,
indoor fan speed is increased by 20min
(ii) If the phenomenon of (i) above is detected again after the acceleration of indoor fan, indoor fan speed is increased
further by 20min
Note (1) Indoor fan speed can be increased by up to 2 taps.
• Compressor frequency drop start temperature (FDT only)
Hs > 50%
Item
Symbol
A
B
Note (1) Frost prevention temperature setting can be selected with the indoor unit function setting of the wired remote control.
(15) Heating overload protection
(a) If the indoor heat exchanger temperature (detected with Thi-R) at 63°C or higher is detected for 2 seconds continuously,
the compressor stops. When the compressor is restarted after a 3-minute delay, if a temperature at 63°C or higher is
detected for 2 seconds continuously within 60 minutes after initial detection and if this is detected 5 times consecutively,
the compressor stops with the anomalous stop (E8). Anomalous stop occurs also when the indoor heat exchanger
temperature at 63°C or higher is detected for 6 minutes continuously.
(b) Indoor unit fan speed selection
If, after second detection of heating overload protection up to fourth, the indoor fan is set at below Hi tap when the
compressor is turned ON, the indoor fan speed is increased by 1 tap.
(16) Anomalous fan motor
(a) After starting the fan motor, if the fan motor speed is 200 min
times within 60 minutes, then fan motor stops with the anomalous stop (E16).
(b) If the fan motor fails to reach at -50 min
(E20).
Symbol
A
1.0
2.5
.
-1
.
-1
Hs ≦ 50%
Low High
Symbol
1.0 2.5 A
2.5 4.0 B
Compressor ON
56
Indoor heat exchanger temperature (°C)
-1 (FDU:-500 min
-
Thermostat-OFF
Indoor heat exchanger temperature (°C)
• Indoor fan speed control start temperature
Item
Low High
Symbol
-0.5 1.0
1.0 2.5
Compressor OFF
63
-1
or less is detected for 30 seconds continuously and 4
-1 ) less than the required speed, it stops with the anomalous stop
18
-
'19 • PAC-SM-334
Thermostat-ON capable
5 minutes
A 10
Indoor
FDT-VH Other
C 18 23
Model
SRC40
FDC10