Heat Controller A-MMH36FA-1, B-MMH12FA-1 manual Cycle Troubleshooting Guide, Trouble analysis

Troubleshooting Guide

CycleTroubleshooting Guide

Trouble analysis

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

Temp. Difference

Operating Current

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

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

Temp. difference : over 8°C(14.4°F)

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.

Suction pressure	Temperature
(Compared with	(Compared with	Cause of Trouble	Description
the normal value)	the normal value)
	High	Defective compressor	Current is low.
Higher
	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.

Notice:

1.The suction pressure is usually 4.5~6.0 kg/cm2(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.

- 65 - Service Manual