Operational Frequency Control Of Outdoor Unit; Pre-Heat Control - Mitsubishi Electric MSC-GE-VB Service Manual

2. Maximum/minimum frequency in each operation mode
Applied model
MUZ-GC25
MUZ-GC35
MUZ-HC25
MUZ-HC35
MUZ-FD25
MUZ-FD35VA
MUZ-FD35VAH/VABH
MUZ-FD50
MUZ-GE25
MUZ-GE35
MUZ-GE42
MUZ-GE50
MUZ-GE60
MUZ-GE71
MUZ-EF25
MUZ-EF35
MUZ-EF42
MUZ-EF50
The operation frequency in COOL mode is restricted by the upper limit frequency after 0.5 - 1 hour as shown below for
dew prevention. It is rated frequency or less.
Upper limit
frequency

2-10. PRE-HEAT CONTROL

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
MUZ-GC/HC/FD/GE
Compressor
Pre-heat control
Defrost thermistor
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) Defrost thermistor reads 20°C or below.
Defrost thermistor monitor hourly, and when defrost thermistor reads 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.)
COOL
Minimum Maximum
32 85
32 98
28 85
28 98
10 52
10 62
10 62
20 85
24 93
20 98
10 90
20 98
20 104
26 120
28 93
20 98
10 90
20 98
Maximum
frequency
Rated frequency or less
0.5 - 1 hour
ON
OFF
ON
OFF
20 °C
30 minutes 1 hour
Operational frequency (Hz)
HEAT
Minimum Maximum
28 105
48 105
28 105
28 98
18 90
18 90
18 115
20 130
32 105
32 98
18 115
20 108
30 117
26 124
30 105
30 98
18 100
20 108
Time
21
DRY
Minimum Maximum
32 41
32 58
28 41
28 41
28 41
28 41
28 41
20 45
48
38
55
38
35 54
20 98
20 104
26 120
28 48
20 55
10 54
20 83