36
No.
Item
Details
Compressor operational frequency range
➁
HEATING
6
Defrosting in
heating
<Conditions to start defrosting>
The system starts defrosting when it satisfies both of the following conditions :
①
The defrost thermistor detects -3°C or below.
➁
Defrost interval (I. e. the accumulated compressor operation time) counted by the controller
board has reached the prescribed value.
<Details of defrosting>
①
The compressor stops for 32.5 seconds and the indoor fan turns OFF.
➁
The 4 - way value reverses and the compressor runs at the defrosting frequency.
③
After the defrosting termination conditions are satisfied, the compressor stops for 32.5
seconds and the 4 - way valve reverses. This is the end of defrosting.
<Conditions to terminate defrosting>
The system terminates defrosting when it satisfies, either of the following conditions :
①
The defrost thermistor d10°C or above.
➁
Defrosting time has reached 10 minutes.
7
High and low
pressure protection
(1) High pressure protection in heating
• The operational frequency, 2 - way valve (only MXZ-32NV), and outdoor fan motor are
controlled according to the indoor coil temperature.
When it rises to nearly 50°C, the operational frequency will be fixed to the value at the moment
and the outdoor fan speed will change to low.
When it rises to nearly 53°C, the operational frequency will be reduced by 4 Hz from the
current value and the 2 - way valve will open.
(2) High pressure protection by high pressure switch (H.P.S : MXZ-18NV , 63H1 : MXZ-32NV)
• The operational frequency, 2 - way valve (only MXZ-32NV), and outdoor fan motor are
controlled by the high pressure switch to protect excessive high pressure.
<Condition to active the protection>
The high pressure protection starts when the high pressure switch turns ON, that is the discharge
pipe pressure rises to 2.75 MPa (28 kg/cm
2
) or above.
+ 0.5
- 1.0
+ 0.05
- 0.1
Number of
operating unit
Minimum
DEFROST
mode
Maximum
Rating
Total capacity
code
MXZ-32NV-
E1
E2
MXZ-18NV-
E2
MXZ-18NV-
E1
1
2
3
4
1
2
3
4
2
3
4
5
6
7
8
-
-
30
40
48
48
58
73
95
115
120
120
105
45
65
58
75
107
112
105
Number of
operating unit
Minimum
DEFROST
mode
Maximum
Rating
Indoor unit
capacity class
1
2
34
34
62
66
82
84
Number of
operating unit
Minimum
DEFROST
mode
Maximum
Rating
Indoor unit
capacity class
1
2
09
09+09
34
34
70
86
43
82
70
86
70
86
70
86
07 or 09
12
09+09
07+12
