115
1 LEV opening correction by suction super heat
(Suction super heat) = (Suction temperature) - (Evaporation temperature)
The LEV opening is corrected as shown in the following table.
2.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 to 92
(
Heating : 80 to 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) to 3 deg
0
3 to
∆
S. H. HEX (i) to 6 deg
+1
6 to
∆
S. H. HEX (i) to 9 deg
+2
9 to
∆
S. H. HEX (i)
+3
Suction superheat (S.H.)
Cooling
Cooling
Heating
Heating
MXZ-32RV-
E1
MXZ-18RV-
E1
LEV opening correction (pulse)
more than 10
8 to10
7 to 8
5 to 7
4 to 5
4 or less
40
30
30
16
8
0
15
10
10
5
3
0
20
15
15
7
0
0
10
10
10
5
0
0
Discharge
temperature (
:
)
Cooling
Cooling
Cooling
Heating
Heating
Heating
MXZ-32RV-
E1
LEV opening correction (pulse)
more than 100
95 to 100
90 to 95
85 to 90
80 to 85
75 to 80
70 to 75
70 or less
10
5
0
-2
-2
-5
-5
-5
10
10
5
5
0
0
-2
-2
10
10
10
5
5
0
-2
-5
10
10
10
5
5
0
-2
-5
5
1
0
-2
-2
-2
-2
-5
20
20
20
2
0
-3
-3
-12
MXZ-18RV-
E1
more than 100
95 to 100
92 to 95
85 to 92
80 to 85
75 to 80
70 to 75
70 or less
more than 100
95 to 100
90 to 95
85 to 90
80 to 85
73 to 80
65 to 73
65 or less
more than 90
85 to 90
80 to 85
75 to 80
70 to 75
65 to 70
60 to 65
60 or less
Discharge
temperature (
:
)
Discharge
temperature (
:
)
Discharge
temperature (
:
)
Two units or more
For capacity class 07 or 09 in single unit operation
