Atlas Copco MD 2500 W VSD, Instruction Book

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11
Instruction book
A double-pole circuit breaker must be installed in the cabinet of
the compressor regulator and connected to the terminals as
shown on the circuit diagram. One pole is connected in the
circuit of the rotor motor. On compressors with relay-controlled
regulators, the other pole of the circuit breaker is connected in
the circuit of the "MD-ON" indicator lamp (H12).
When voltage is supplied to a compressor with a relay-controlled
regulator, the lamp will light up (lamp test). If the contacts are
closed and the compressor subsequently started, the lamp will
remain alight, thus indicating that the dryer will be operative
when the compressor is loaded. If, on the other hand, the contacts
are open, the lamp will go out when the compressor is started,
indicating that the dryer is out of service. This will also be the
case if, during operation, the circuit breaker should trip due to
an overload.
For air-cooled dryers, a circuit breaker must be installed in the
cabinet of the compressor. Consult section 2.3 for the correct
setting.
Fig. 1.11 Electrical circuit diagram of MD300 W/MD1000 W connected to ZR3, ZR4 and ZR5 with Elektronikon regulator
with LED display as shown above