Mitsubishi Heavy Industries FDT200VSAWPVH Service Manual page 38

(c) Heating high pressure protection
(i) Protective control
1) As the indoor heat exchanger temperature (Thi-R) exceeds the setting value, the compressor speed (frequency) is
controlled to suppress the rise of high pressure.
2) Control value A is changed from 57°C to 51°C by number of 63H1 operations.
Reset
Indoor heat exchanger temperature (°C)
3) If indoor heat exchanger temperature(Thi-R) is less than the control value A continuously for 6minutes, protective
control finishes.
(ii) Anomalous stop control
Operation control function by the indoor unit control - See the heating overload protection, page 18.
(d) Anomaly detection control by the high pressure switch (63H1)
(i) If the pressure rises and operates the high pressure switch (opens at 4.15MPa/closes at 3.15MPa), the compressor stops.
(ii) Under any of the following conditions, E40 is displayed and it enters the anomalous stop mode.
1) When it occurs 5 times within 60 minutes that pressure rises and the compressor is stopped by 63H1.
2) When 63H1 has been in the open state for 30 minutes continuously, including the stop of compressor.
(e) Low pressure control
(i) Protective control
1) If the value detected by the low pressure sensor (PSL) exceeds the setting value, the compressor speed (frequency)
is controlled to restrain the drop of pressure.
2) If low pressure sensor (PSL) is 0.189MPa or higher, protective control finishes.
(ii) Anomalous stop control
1) When a value detected by the low pressure sensor (PSL) satisfies any of the following conditions, the compressor
stops for its protection.
a) When the low pressure drops to 0.079MPa or lower for 15 seconds continuously.
b) At 10 minutes after the start of compressor, the suction superheat becomes 30°C or more for 60 seconds
continuously and the low pressure becomes 0.15MPa or lower.
2) E49 is displayed under any of the following conditions and it enters the anomalous stop mode.
a) When the low pressure drops 5 times within 60 minutes and the compressor stops under any of the above conditions.
b) When a value detected with the low pressure sensor becomes 0.079MPa or under for 5 minutes, including the
stop of compressor.
3) However, when the control condition 1). a) is established during the compressor protection start III, E49 is
displayed at initial stop and it enters the anomalous stop mode.
4) If low pressure sensor (PSL) is 0.227MPa or higher and 3 minutes took after the compressor stops, it becomes
possible to restart from the remote control.
( f ) Compressor pressure ratio protection control
(i) During heating operation, if the indoor heat exchanger temperature (Thi-R) and low pressure sensor (PSL) exceed the
setting values at 10 minutes after the start of compressor, the compressor speed (frequency) is controlled to protect the
compressor.
(ii) This control is not performed during the outdoor fan ON and for 10 minutes from the start of outdoor fan.
(iii) This control is not performed during defrost operation and at 10 minutes after the reset of defrost operation.
(iv) When there are 3 indoor heat exchanger temperatures (Thi-R), the highest temperature is detected.
(v) If the indoor heat exchanger temperature (Thi-R) and low pressure sensor (PSL) is without "Reduces compressor
frequency at each minute" range in the following figure continuously for 6minutes, protective control finishes.
Reduces compressor frequency
at every 30 seconds.
A
Reduces compressor frequency
at every 30 seconds.
0.150
Low pressure (MPa)
64
°C
32
°C
0.150
Low pressure (MPa)
37
-
Model
FDC200-280
Retention
Reset
0.189
Reduces compressor frequency at each minute.
Reset
0.425
-
'21 • PAC-SM-383
Control value A (°C)
57-51