Selection And Operation Of Compressors With Frequency Converters; Commissioning; Preparations For Start-Up; Pressure Integrity Test - Danfoss BOCK UL-HGX44e Operating Manual

5 | Electrical connection

5.12 Selection and operation of compressors with frequency converters

For safe operation of the compressor, the frequency converter must be able to apply an overload of
at least 140% of the compressor's maximum current (I-max.) for at least 3 seconds.
When using frequency converters, the following things must also be observed:
1. The maximum permissible operating current of the compressor (I-max) (see type plate or
technical data) must not be exceeded.
2. If abnormal vibrations occur in the system, the affected frequency ranges in the frequency
converter must be blanked out accordingly.
3. The maximum output current of the frequency converter must be greater than the maximum
current of the compressor (I-max).
4. Carry out all designs and installations in accordance with the local safety regulations and common
rules (e.g. VDE) and regulations as well as in accordance with the specifications of the frequency
converter manufacturer
The permissible frequency range can be found in the technical data chapter 11, p. 35/36.
D
US
Rotational speed
F
range
E
Start-up time
Switch-off time
f-min/f-max see chapter 9: Technical data: permissible frequency range

6 | Commissioning

6.1 Preparations for start-up

The compressor has undergone trials in the factory and all functions have been tested. There are
therefore no special running-in instructions.
Check the compressor for transport damage!

6.2 Pressure integrity test

The compressor has been tested in the factory for pressure integrity. If however the entire system is
to be subjected to a pressure integrity test, this should be carried out in accordance with EN 378-2
or a corresponding safety standard without the inclusion of the compressor.
24 | AQ450440081306en-US0201
0 - f-min
< 1 s
To protect the compressor against inadmissible operating conditions,
high pressure and low pressure pressostats are mandatory on the
installation side.
f-min - f-max
ca. 4 s
immediately
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