Single compressors
Operating conditions
Application envelopes
0
10
20
30
40
50
60
5
15
25
35
45
55
65
70
157
152
147
142
137
132
127
122
117
112
107
102
97
92
87
82
77
72
67
62
57
52
47
42
37
32
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
Co
nd
ensing
te
m
perature
(°
C)
VZH operating map - R410A (SH 6 K)
-40
-30
-20
-10
0
10
20
-35
-25
-15
-5
5
15
25
Evaporating temperature (°C)
15-100 rps
20-100 rps
30-100 rps
40-100 rps
60-100 rps
Voltage: 400-460V/208-230V
°C
°F
0
10
20
30
40
50
60
5
15
25
35
45
55
65
70
157
152
147
142
137
132
127
122
117
112
107
102
97
92
87
82
77
72
67
62
57
52
47
42
37
32
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
Co
nd
ensing
te
m
perature
(°
C)
VZH operating map - R410A (SH 6 K)
-40
-30
-20
-10
0
10
20
-35
-25
-15
-5
5
15
25
Evaporating temperature (°C)
15-100 rps
20-100 rps
30-100 rps
40-95 rps
60-100 rps
60-95 rps
Voltage: 380V
°C
°F
40-100 rps
Short cycle control is provided directly by the
CDS803 frequency converter, when parameter
28-00 is enabled.
The function is factory set to enabled, with
minimum running time to 60 seconds and the
interval between starts to 300 seconds.
Short cycle settings are accessible in the
parameter 28.0x list, in the “compressor functions”
menu.
If system is fully controlled by an external main
controller, it is recommended to limit the start/
stop frequency to 12 times per hour.
The operating envelopes for VZH scroll
compressors are given in the figures below,
where the condensing and evaporating
temperatures represent the range for steady state
operation. Under transient conditions, such as
start-up and defrost, the compressor may operate
outside this envelope for short periods.
The figures below show the operating envelopes
for VZH compressors with refrigerants R410A.
Due to bearing loads and scroll stability, there
will be speed restrictions on the envelops.
The operating limits serve to define the
envelope within which reliable operation of the
compressor is guaranteed:
• Maximum discharge gas temperature: +135°C.
• Minimum suction superheat should be above
5 K and minimum sump superheat should be
above 6 K due to the risk of liquid flood back.
• Attention to suction line insulation to reduce
useless superheat.
• Minimum and maximum evaporating and
condensing temperatures as per the operating
envelopes.
• VZH drive can only protect the compressor from
over current. Customers need to have a high
pressure, low pressure sensor and discharge
temperature thermostat to fully protect the
envelop. Since out of map running will threaten
the reliability of compressor, customers must
qualify map protection under all extreme
conditions.
Short cycle timer function
25
FRCC.PC.034.A2.02
Application Guidelines
