Heat Controller B-MMH09FA-1 Manuel D’Utilisation

Service Manual

1. Check temperature difference between intake and discharge air, as well as the operating current.

All of the refrigerant many have
leaked out. 
Restriction in the refrigeration cycle.

Refrigerant leakage
Clog of refrigeration cycle
Defective compressor

Excessive amount of refrigerant

Normal

Notice:
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relatively higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.

2. Check temperature and pressure of refrigeration cycle.

Notice:
1. The suction pressure is usually 4.5~6.0 kg/cm

2

(64.0~85.34psi) at normal condition.

2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrapping it

with putty.

Temp. difference 

: approx. 0°C(0°F)

Current

: less than 80% of

rated current

Temp. difference 

: approx. 8°C(14.4°F)

Current

: less than 80% of

rated current

Temp. difference 

: less than 8°C(14.4°F)

Current

: near the rated cur-

rent

Temp. difference 

: over 8°C(14.4°F)

Temp. Difference 

Operating Current

Suction pressure

Temperature

(Compared with

(Compared with

Cause of Trouble

Description

the normal value)

the normal value)

High

Defective compressor

Current is low.

Normal

Excessive amount of 

High pressure does not quickly 

refrigerant

rise at the beginning of operation.

Insufficient amount of

Current is low.

Lower

Higher

refrigerant(Leakage)Clogging
or Refrigerant Cycle Restrictions.

Higher