Mitsubishi MT300 User Manual

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142
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Service
'10 • HM-T-149
3) Heating high pressure protection
a) Protective control
i) If the liquid line temperature of water heat exchanger (BT15=Thi-L) or the condensing saturated temperature
(CST), whichever the higher, exceeds the setting value, the compressor speed (frequency) is controlled to
suppress the rise of high pressure.
ii) Control value A is updated to an optimum value automatically according to the operating conditions.
Liquid line temperature of water heat exchanger (°C)
A
Reset
Reduce compressor speed at every 30
seconds for 100 model (10 seconds for
71 and 140 models)
b) Anomalous stop control
If the liquid line temperature of water heat exchanger (BT15=Thi-L) or the condensing saturated temperature (CST),
whichever the higher, exceeds the setting value for 2 seconds, compressor stops.
The compressor automatically restarts when the temperature gets 47°C or lower.
47
65
Compressor stop
Compressor operation
Liquid line temperature of water heat exchanger or
condensing satureted temperature (°C)
4) Anomaly detection control by the high pressure switch (63H1)
i) If the high pressure rises and activates the high pressure switch (opens at 4.15MPa/close at 3.15MPa), the
compressor stops.
ii) Under any of following conditions, HP alarm is displayed and E40 is recorded in the Error Log, and it enters the
anomalous stop mode.
①
When high pressure exceeds the setting value and the compressor is stopped by 63H1 5 times. within 60
minutes.
②
When 63H1 has been in the open state for 60 minutes continuously including the time of compressor stopping.
5) Low pressure control
a) Protective control
If the value detected by the low pressure sensor (LTP) exceeds the setting value, the compressor speed (frequency) is
controlled to restrain the drop of pressure.
0.150
0.189
Reduce compressor speed at every 30 seconds
Reset
Low pressure (MPa)
Retention
b) Anomalous stop control
i) When a value detected by the low pressure sensor (LPT) satises any of the following conditions, compressor
stops.
①
When the low pressure drops to 0.079MPa or lower for 15 seconds continuously.
ii) Under any of the following conditions, LP alarm is displayed and E49 is recorded in Error Log, and it enters the
anomalous stop mode.
①
When the low pressure drops and the compressor stops under any of above conditions 3 times within 60
minutes.
②
When the low pressure sensor detects 0.079MPa for 5 minutes continuously including the time of compressor
stopping
Model Control value A
FDCW71VNX 60-63°C
FDCW100VNX 60°C
FDCW140VNX 60-63°C
Operation control function by the outdoor unit controller

Mitsubishi MT300 Specifications

General

Brand	Mitsubishi
Model	MT300
Category	Heat Pump
Language	English