Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual page 331

(c) Heating high pressure protection
i) Protective control
a) As the indoor unit heat exchanger temperature (Thi-R) exceeds the setting value, the compressor speed
(frequency) is controlled to suppress the rise of high pressure.
b) Control value A is updated to an optimum value automatically according to the operating conditions.
Reduces compressor frequency
at every 30 seconds.
Reset
A
Indoor unit heat exchanger temp. (°C)
ii) Anomalous stop control
Operation control function by the indoor unit control - See the heating overload protection, page 18.
iii) Adaptation to existing piping, stop control
If the existing piping adaptation switch, SW5-1, is turned ON, the compressor stops to protect existing piping
when the indoor unit heat exchanger temperature (Thi-R) exceeds the setting value.
Reset
47
Indoor unit heat exchanger temperature (°C)
(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.
a) When it occurs 5 times within 60 minutes that pressure rises and the compressor is stopped by 63H1.
b) When 63H1 has been in the open state for 60 minutes continuously, including the stop of compressor.
(e) Compressor pressure ratio protection control
i) During heating operation, if the indoor unit heat exchanger temperature (Thi-R) and the low pressure saturation
temperature (SST) 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 unit 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 unit heat exchanger temperatures (Thi-R), the highest temperature is detected.
65
°C
33 °C
-41
Low pressure saturation temperature (
(f) Over-current protection current safe controls I, II
Detecting the outdoor unit inverter input (primary) current and the output (secondary) current, if the current values
exceed setting values, the compressor speed (frequency) is controlled to protect the inverter.
Retention
Reset
B
Current (A)
(Fig. C) The control value "A" and the reset value vary depending
on the compressor speed.
24
22
20
18
16
14
12
Outdoor air temp.43℃
10
40 50 60 70
Compressor speed (frequency) (rps)
Compressor stop
58
Reduces compressor frequency at each minute.
Resert
-16
°C )
Reduces frequency
at each minute.
A
Outdoor air temp.35℃
80 90 100 110 120 130
330
-
Existing piping adaptation switch: SW5-1
Model OFF (Shipping)
100-140
Note (1) Adaptation to existing piping is at ON.
Cooling
Model
Control
value A
100 13.5 (23.0) 12.5 (22.0) 13.5 (23.0) 12.5 (22.0)
Primary
current
125,
13.5 (23.0) 12.5 (22.0) 13.5 (23.0) 12.5 (22.0)
side
140
100 12.0 (Fig.C) 11.0 (A-1) 12.0 (23)
Secandary
current
125,
12.0 (Fig.C) 11.0 (A-1) 12.0 (23)
side
140
Note (1) Value in ( ) are for the single phase models.
-
'19 • PAC-T-327
ON
Control value A (°C)
48-54 46-52
Heating
Reset Control Reset
value B value A value B
11.0 (22)
11.0 (22)