Operating Characteristics And Control Capabilities - Mitsubishi Electric e Series Service Handbook

[ VII Control ]

[2] Operating characteristics and Control Capabilities

Outline of Control Method
-1- Operating characteristics
Function
Unit Pressure
protection switch
Pressure
sensor
Compressor overcurrent relay
Fan overcurrent protection
Thermis-
tor
Pump Water temperature thermister
control
Freeze-up protection circuit
HWE1417B
Component Symbol
High-pressure 63H
switch
High-pressure HP
sensor
Low-pressure LP
sensor
Discharge refrig- TH11
erant temp. TH21
(Discharge temp.
overrise protec-
tion)
Outlet water TH3
Air-side HEX re- TH6
frigerant temp. TH26
Water-side HEX TH7
refrigerant temp. TH27
ACC inlet refriger- TH5
ant temp. TH25
Inverter heatsink THHS
temp.
TH1-3
Control/ Ac- Unit
Detection tion
HP ON MPa
OFF MPa
HP OFF MPa
LP OFF MPa
Compressor OFF A
current
Fan current Limit A
Discharge OFF ºC
gas temp.
Outlet water OFF ºC
temp.
(cooling)
Outlet water OFF ºC
temp.
(heating)
SC - ºC
(cooling)
SC - ºC
(heating)
SH OFF ºC
INV. heat- OFF ºC
sink temp.
Water temp. ON ºC
OFF ºC
- 96 -
Trigger condition
(3.25)
4.15
3.9

The low pressure has dropped below 0.1 MPa.

During water cooling, the low pressure has
dropped below 0.56 MPa.

During brine cooling, the low pressure has
dropped below 0.25 MPa.
33
1.9

If a discharge gas temperature of 120ºC or above
was detected three times in 1 hour, the unit will
make an abnormal stop.
An outlet water temperature of 3ºC was detected.
An outlet brine temperature of -15ºC was detected.
An outlet water temperature of -65ºC was detected.
-
-
ACC inlet SH above 20ºC has been detected for 10
minutes.
A temperature above 95ºC has been detected for
10 minutes.
3
5
The pump turns on when the water temperature
has reached below the "ON" threshold when the
compressor is stopped.
GB