Mitsubishi Heavy Industries ESA30E-25, Technical Manual

Page: 53 / 239

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'15 • HM-T-246
2.9 Control
(1) Functional components for refrigerant cycle
Symbol N ame of component Function Details
CM Inverter scrotary compressor The compressor speed is controlled to maintain nominal heating capacity
water outlet temperature set by remote control.
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Control range of compressor speed: -0rps
The target speed of compressor can be checked with MenteP C.
FMo, Fan motor Low pressure control is done by fan speed.
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The fan speed is controlled to maintain the low pressure .± 0.MP a.
Control range of fan speed: 0-000rpm
E E V G E lectronic expansion valve for
gas cooler E E V Gis used for discharge pipe temperature control
Snow protection control is done by fan rotation.
If outdoor air temperature is ° C or lower and during 0 minutes period after st
opping fan motor, fan rotates at 00min
- for 0 minutes.
The target temperature of discharge pipe is decided by outdoor air temperature,
feed water inlet temperature and hot water outlet temperature set by remote control.
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Control range of target discahrge pipe temperature: -° C
The target discharge pipe temperature can be checked with MenteP C.
E E V H, E lectronic expansion valve for
air heat exchanger E E V H, are used for low pressure control and suction superheat control of
compressor
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Control range of suction superheat: -degC
SV -IN J Solenoid valve for injection Refrigerant gas from receiver is injected to the intermediate pressure port of
compressor.
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If gas refrigerant injection is required, SV -IN J is opened.
Injection circuit As for the detail of gas injection control, please refer to [Injection control].
SV HG Solenoid valve for hot gas
bypass During defrost control, SV HG is opened.
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As for the detail of defrost control, please refer to [Defrost control].
SV -OIL Solenoid valve for oil
separator SV -OIL is used for oil return control from oil separator.
If compressor is ON and outdoor air temperature is -° C or higher, SV - OIL is
opened.
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H- High pressure switch H- is used for the detection of high pressure anomaly.
When H- is opened, it makes the compressor stopped.
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As for the contents of high pressure anomaly detection control, please refer
to [High pressure protection control].
P SH High pressure sensor P SH is used for high pressure protection control and the detection of high
pressure anomaly.
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As for the contents of high pressure anomaly detection control and high
pressure protection control, please refer to [High pressure protection control].
P SL Low pressure sensor P SL is used for fan control, suction superheat control, low pressure
protection control and the detection of low pressure anomaly.
P age
As for the contents of low pressure protection control, please refer to [Low
pressure protection control].
P SM Intermediate pressure sensor P SM is used for open/close control of injection circuit.
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As for the detail of injection control, please refer to [Injection control].
Tho-A Outdoor air temperature sensor Tho-A is used for compressor control, anti-freeze control of water pipe and
E E V control.
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Tho-C Under-dome temperature sensor Tho-C is used for under-dome temperature protection control.
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Tho-D Discharge pipe temperature sensor Tho-D is used for discharge pipe temperature control, discharge pipe temperature
protection control and detection of discharge pipe temperature anomaly.
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As for the contents of discharge pipe temperature anomaly detection control and
discharge pipe temperature protection control, please refer to [Discharge pipe
temperature protection control].
Tho-G, temperature sensor at inlet and
outlet port of gas cooler Tho-G, are used for checking the operation status.
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Tho-G, can be checked with MenteP C.
Tho-IN J temperature sensor at inlet
injection port Tho-IN J is used for checking the operation status.
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Tho-IN J can be checked with MenteP C.
Tho-M temperature sensor at inlet port of
intermediate pressure receiver Tho-M is used for checking the operation status.
Tho-M can be checked with MenteP C.
Tho-P P ower transistor temperature
sensor Tho-P is used for power transistor temperature protection control.
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As for the contents of power transistor temperature protection contro l, please refer
to [P ower transistor temperature protection control].
Tho-R,,, temperature sensor at inlet and
outlet port of air heat exchanger
Tho-R, , , are used for defrost control and oil return control.
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Tho-S Suction pipe temperature sensor Tho-S is used for suction superheat control -
0 CH Crankcase heater CH is used for warming up the compressor -
DH
H
Drain pan heater
Anti-freezing heater
DH is used for preventing from freezing drain pan
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If outdoor air temperature is ° C or lower and outdoor unit is in operation mode
during
minutes period after finishing defrosto operation, or during snow protection
control, DH is energized.
H is used for preventing from freezing water pipings.
If outdoor air temperature is ° C or lower and heat pump water heater is off, H is energyized.
according to the outdoor air temperature, feed water inlet temperature and hot
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