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Verfügbare Sprachen
Verfügbare Sprachen
Compressor
ESH7
ELH7
ELA7
ELV21
ELV52
ORBIT
GED8
GSD6 .. GSD8
GSU6 .. GSU8
ORBIT tandem / trio
Tab. 1: Speed and frequency ranges of BITZER scroll compressors with external frequency inverters (also observe the application limits and the
maximum current consumption of the motor)
Please consult BITZER for external VSD application guidelines.
Application limits
In general, compressor models approved for operation with frequency inverter have undergone complete load cyc-
ling testing at minimum and maximum speeds. Normally, the application limits correspond to the fixed speed limits
published e.g. in the BITZER SOFTWARE. However, some special considerations may require restrictions at cer-
tain speeds.
The following figure shows an example of application limits for an ORBIT compressor at different frequencies. The
compressor may only be operated below the indicated frequency lines ‒ otherwise, select a special voltage motor
( Special voltage motors ).
70
t [°C]
c
60Hz
60
70Hz
75Hz
50
40
30
20
-30
-20
Fig. 5: Exemplary and simplified application limits for an ORBIT scroll compressor with frequency inverter at 60, 70 and 75 Hz (limits due to mo-
tor temperature or maximum current). The compressor may only be operated below the indicated frequency lines.
t
: evaporation temperature, t
o
c
Grey area: limitations for frequencies < 50 Hz possible.
Specific application limits for particular compressors, motors and refrigerants are given in the BITZER SOFTWARE
or available on request.
Vibrations
Compressor vibrations and pressure pulsations are normally very low by design. However, they can evoke reson-
ance frequencies in piping and heat exchangers (i.e. meet the natural frequency of the system) which result in sys-
tem sound, vibration, and potentially in piping fatigue and leakage. Possible sources of vibrations are:
EST-420-6 // PDF Download
Frequency range (Hz)
35 .. 65
35 .. 65
35 .. 65
44 .. 140
44 .. 130
35 .. 60
35 .. 75
35 .. 75
see below ( Tandem and trio operation )
t
oh
-10
0
10
t [°C]
o
: condensing temperature, Δt
oh
= 10 K
30
: suction gas superheat
-1
Speed range (min
)
2000 .. 3800
2000 .. 3800
2000 .. 3800
2500 .. 8000
2500 .. 7500
2000 .. 3500
2000 .. 4400
2100 .. 4500
46
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