Mitsubishi HMA100V Technical Manual page 297

Alarm list
Alarm with automatic reset
Alarm Alarm text on the
no. display
70 Low condenser out
71 High KF
72 Anti freeze HX
73 Freeze prot
75 Current limit
77 Aborted defrost
78 Min flow protection
Temperature limiter alarm
The following alarm blocks both outdoor unit and electric heater.
Alarm Alarm text on the
no. display
3 TB alarm
Indoor unit alarm
The following alarms stop the operation of indoor unit. Electric heater is activated at min permitted supply temperature.
Alarm Alarm text on the
no. display
4 OU power failure
5 Low condenser out
6 High KF
7 Anti freeze HX
14 Aborted defrost
Triggers alarm
When condenser supply (BT12) is less than 5°C.
When condenser supply is greater than 60°C and
there are more than 120 seconds since shifting to
the heating system.
When the low pressure is less than
ling mode.
When the outdoor temperature drops below 0°C and
the operating mode does not permit heating.
Too high current output from the house.
When the low pressure is less than threshold value
according to water temperature.
When the temperature difference between
BT12 and BT3 is bigger than predetermined value
during defrost operation.
Description
Temperature limiter in indoor unit has tripped.
Description
No voltage to the outdoor unit from indoor unit.
Too low temperature out from the condenser.
Occurs if alarm 70 occurs 3 times within an hour.
Too high temperature out from the condenser.
Occurs if alarm 71 occurs 3 times with in an hour.
Anti-freeze of heat exchanger.
Occurs if alarm 72 occurs 3 times with in an hour.
Occurs if alarm 70 or 77 occurs 10 times continu-
ously during defrost operation.
Resets alarm
When condenser supply is greater than 14°C.
When condenser supply is lower than 51°C.
0.65 MPa in coo- When the low pressure is greater than
condenser out is greater than 14 degrees.
When the outdoor temperature rises above 1°C.
When the current output decreases.
Defrost operation is forcibly finished and heating
operation restarts automatically.
Defrost operation is forcibly finished and heating
operation restarts automatically.
May be due to
- The temperature limiter has tripped during
transportation
- High temperature in indoor unit
- Blown circuit fuse
- Tripped miniature circuit breaker
Also see the troubleshooting guide on page 151.
May be due to
- Blown circuit fuse
- Tripped miniature circuit breaker
Also see the troubleshooting guide on page 152.
- Low temperature during cooling
- Low flow during cooling
Also see the troubleshooting guide on page 153.
- Low flow in heating operation
- Too high set temperatures
Also see the troubleshooting guide on page 154.
- Low flow during defrost
Also see the troubleshooting guide on page 155.
- Refrigerant leakage
- Inproper installation place of outdoor unit
- Insufficient water flow
Also see the troubleshooting guide on page 158.
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'10 • HM-T-149A
Service
Alarm list
0.83 MPa or
69