Service manual
72
Number of
operating
unit
1
2
3
4
Capacity
code
1, 2, 3, 4
5, 6
7, 8
9, 10
11, 12
13, 14
15 or above
2, 3, 4, 5, 6, 7
8, 9, 10
11, 12, 13
14, 15, 16
17, 18, 19, 20, 21
22, 23, 24 or above
3, 4, 5, 6, 7, 8, 9, 10
11, 12, 13, 14, 15
16, 17, 18, 19, 20
21, 22, 23, 24, 25
26, 27, 28, 29
30 or above
4, 5, 6, 7, 8, 9, 10
11, 12, 13, 14, 15
16, 17, 18, 19, 20
21, 22, 23, 24, 25
26, 27, 28, 29, 30
31, 32, 33, 34, 35
36 or above
Min.
15
15
15
15
15
15
15
24
24
24
24
24
52
52
63
63
COOL (Hz)
Max.
58
58
58
62
62
62
65
80
80
80
80
80
90
90
94
94
DRY
(Hz)
20
20
25
44
44
44
44
31
31
31
31
59
65
65
65
65
Min.
22
22
22
22
22
22
22
35
35
35
35
35
39
39
52
52
Max.
37
37
37
90
90
90
90
58
58
90
94
94
94
94
94
94
HEAT (Hz)
Defrost
37
37
37
80
80
80
80
58
58
80
80
80
80
80
80
80
MXZ-4A80VA
MXZ-2A52VA
<Control status>
The control performs when the all the following status are satisfied;
• When one or more indoor units are operating in HEAT mode. (Excluding thermostat OFF)
• When discharge temperature becomes 107: or more.
• When it passed 60 minutes or more since the operation has started or the last refrigerant recovery has controlled.
<Control details>
LEV opening of indoor unit not operating is controlled to be 80 pulse.
<Control finish status>
The control finishes either as follows. However, the LEV opening is considered to be 59 pulse.
• When it passed 60 seconds since the control has started.
• When the discharge temperature is 90: or less.
4-6. REFRIGERANT RECOVERY CONTROL ON HEATING
4-4. HEAT DEFROSTING CONTROL
(1) Conditions to enter defrosting mode
1. When temperature of defrosting thermistor is -3: or less.
2. When specified non-defrosting time, is counted in the control p.c. board is satisfied.
(Total time of compressor operating)
Going to defrosting mode at both condition of 1 and 2.
(2) Defrosting operation
1. Compressor stops for 50 seconds, Indoor fan is off, Defrosting lamp lights.
2. 4-way valve reverses flow, Compressor operates by the frequency in heat defrosting control.
3. After compressor stops for 35 seconds, 4-way valve reverses flow, then defrosting finishes.
(3) Conditions to finish defrosting mode
1. When the defrosting thermistor temperature is 13.2: or more.
2. When it has spent 10 minutes for defrosting.
Defrosting finishes at condition of 1 or 2.
This protection controls the compressor ON/OFF and operation frequency according to temperature of the discharge
temperature thermistor.
(1) Compressor ON/OFF
When temperature of the discharge temperature thermistor exceeds 116:, the control stops the compressor.
When temperature of the discharge temperature thermistor is 80: or less, the controls starts the compressor.
(2) Compressor operation frequency
When temperature of the discharge temperature thermistor is expected to be higher than 116:, the control decreases 12Hz
from the current frequency.
When temperature of the discharge temperature thermistor is expected to be higher than 111: and less than 116:, the con-
trol decreases 6Hz from the current frequency.
When temperature of the discharge temperature thermistor is expected to be higher than 104: and less than 111:, the con-
trol is set at the current frequency.
4-5. DISCHARGE TEMPERATURE PROTECTION CONTROL
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