Pre-Heat Control - Mitsubishi Electric MSC-GE-VB – E Service Technical Manual

2-10. PRE-HEAT CONTROL

MUZ-GC, HC, FD, GE
1. Outline
Compressor is energized to improve the start-up of compressor at a low outside temperature even when compressor
is stopped.
2. Pre-heat control
Compressor
Pre-heat control
Outside temperature
Pre-heat control ON condition
(1) Compressor is not operating. (However, pre-heat control is still OFF for 30 minutes after compressor is stopped,
regardless of the outside temperature.)
(2) Outside temperature is 20°C or below.
Outside temperature is monitored hourly, and when outside temperature is 20°C or below, pre-heat control is turned
ON.
When pre-heat control is turned ON, compressor is energized about 50 W (40-60 W). (Compressor and fan are not
operated.)
1. Outline
The compressor is energized even while it is not operating.
This is to generate heat at the winding to improve the compressor's start-up condition.
Power ON
OFF
Compressor ON
OFF
Outside temperature
20°C
Pre-heat ON
OFF
2. Pre-heat control ON condition
(1) Pre-heat control is turned ON for 15 or 30 min after the breaker is turned ON.
(2) 30 min. after the unit is stopped, pre-heat control is turned ON for 15 or 30 min. and turned OFF for 30 min.
This is repeated as shown in the graph until the breaker is turned OFF.
When outside temperature is 20°C or below, pre-heat control is ON for 30 min.
When outside temperature is 21°C or above, pre-heat control is ON for 15 min.
NOTE: When the unit is started with the remote controller, pre-heat control is turned OFF.
Compressor uses 50 W when pre-heat control is turned ON.
ON
OFF
ON
OFF
20 °C
30 minutes 1 hour
30min.
Start
Breaker ON
operation
30min. 30min. 30min.
Stop
operation
21 21
30min. 30min. 15min. 30min. 15min. 30min.
When outside
temperature is
above 20°C