Protection Of Explosion Proof Machines - Siemens SIPROTEC 7SJ62 Handbuch

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Protection of Explosion Proof Machines

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For installing the equipment standard EN 60079–14 or VDE 0165, part 1 (electrical
equipment for hazardous areas) must be observed:
The 7SJ62/63/64 multi-functional protection system provides the overload protection
for cage-rotor induction motors (see also EN 50019, Appendix A) as demanded in this
standard - provided that the following requirements are met:
• The 7SJ62/63/64 multi-functional devices must be set to the rated current of the
motor. The tripping characteristic must selected such that for blocked rotor current
the tripping time lies within the time t
Note: In case of heavy starting, this setting initiates the tripping already during the
starting time. In this case special protection measures must be taken (e.g. additional
speed monitoring during motor start and specially adjusted setting of the 7SJ62/63/64
multi-functional relay) to ensure that the threshold temperature is not exceeded.
Here the particular requirements of the conformity declaration of the motor must be
observed or the manufacturer of the motor must be contacted for verification of this
topic.
• If the locked-rotor time t
efficacy of the protection must be proved.
• If motor starting time supervision is implemented via tachometric relay and binary
input, the signal of the tachometric relay must be supplied via a safe separation of
the binary input.
• The 7SJ62/63/64 protective relays must be set up outside the hazardous area.
indicated on the motor rating plate.
BRT
of the machine under protection is smaller than 5 s,
E
7SJ62/63/64 Additional Information
C53000-B1174-C170-1