33
No.
Item
Details
①
LEV opening correction by suction superheat
(Suction superheat) = (Suction temperature) - (Evaporation temperature)
The LEV opening is corrected as shown in the following table.
➁
LEV opening correction by discharge temperature
The LEV opening is corrected to 55 pulse when it has been corrected consecutively 20 times
due to the discharge temperature (Td) of 60
;
or below, or when the discharge temperature falls
below 35°C. When such a status has continued for 10 minutes, the compressor stops and
enters the 3 - minute time delay.
If the compressor stops five times during a continuous operation, the unit stops due to
abnormality.
❈
For capacity class 12(13) or 18 in single-unit operation, the stabilized range shifts to the next
higher level.
I. e. Cooling : 85<Td
<
=
92
(
Heating : 80<Td
<
=
91
)
③
LEV opening correction by gas pipe temperature (effective in cooling operation only.)
(1) Maximum correction width : +14 pulse
(2) Single correction width : 1, 2, or 3 pulse
(3) Control details
1) S.H. HEX of each operating unit is calculated by using the following formula.
S.H. HEX (i) = (Gas pipe temperature (i)) - (Evaporation temperature)
2) The minimum valve is selected from each S. H. HEX.
3) From S. H. HEX (i) calculated in step 1) and the minimum value obtained in step 2), the
difference of each S. H. HEX (
∆
S. H. HEX (i)) is calculated as follows.
∆
S. H. HEX (i) = (S. H. HEX (i) - S. H. HEX (min))
4) Each LEV opening is controlled based on
∆
S. H. HEX (i) obtained in step 4).
∆
S. H. HEX (i) and LEV control width
Range of
∆
S. H. HEX (i)
LEV variation for corresponding unit
∆
S. H. HEX (i)
<
=
3 deg
0
3<
∆
S. H. HEX (i)
<
=
6 deg
+1
6<
∆
S. H. HEX (i)
<
=
9 deg
+2
9<
∆
S. H. HEX (i)
+3
Suction superheat (S.H.)
Cooling
Cooling
Cooling
Heating
Heating
Heating
MXZ-32NV-
E1
E2
MXZ-18NV-
E2
MXZ-18NV-
E1
LEV opening correction (pulse)
10 < S.H
8 < S.H
[
10
7 < S.H
[
8
5 < S.H
[
7
4 < S.H
[
5
2 < S.H
[
4
0 < S.H
[
2
S.H
[
0
20
15
15
8
4
0
0
0
15
10
10
5
3
0
0
0
40
30
30
16
8
0
0
0
15
10
10
5
3
0
0
0
20
15
15
7
0
0
0
0
10
10
10
5
0
0
0
0
Discharge
temperature (
:
)
Cooling
Cooling
Cooling
Heating
Heating
Heating
MXZ-32NV-
E1
E2
LEV opening correction (pulse)
100 < Td
95 < Td
[
100
90 < Td
[
95
85 < Td
[
90
80 < Td
[
85
75 < Td
[
80
70 < Td
[
75
65 < Td
[
70
Td
[
65
-
10
5
0
-2
-2
-5
-5
-5
-5
-
10
10
5
5
0
0
-2
-2
-2
-
10
10
10
5
0
-2
-2
-5
-5
-
10
10
10
5
5
0
-2
-5
-5
-
5
5
5
1
0
-2
-2
-2
-2
-5
20
20
20
20
20
2
0
-3
-3
-12
MXZ-18NV-
E1
E2
100 < Td
95 < Td
[
100
92 < Td
[
95
85 < Td
[
92
80 < Td
[
85
75 < Td
[
80
70 < Td
[
75
60 < Td
[
70
Td
[
60
-
100 < Td
95 < Td
[
100
90 < Td
[
95
85 < Td
[
90
80 < Td
[
85
73 < Td
[
80
65 < Td
[
73
60 < Td
[
65
Td
[
60
-
100 < Td
95 < Td
[
100
90 < Td
[
95
85 < Td
[
90
80 < Td
[
85
75 < Td
[
80
70 < Td
[
75
65 < Td
[
70
60 < Td
[
65
Td
[
60
Discharge
temperature (
:
)
Discharge
temperature (
:
)
Discharge
temperature (
:
)
Two units or more
For capacity class 07 or 09 in single unit operation
