For Synchronisation of DG Sets Sometimes we people use NIC (Neutral Isolation C

For Synchronisation of DG Sets Sometimes we people use NIC
(Neutral Isolation Contactor) Instead of 4-pole ACB or any
switchgerar..Please guide me why is it so????

Question Posted / mohd mansoor

4 Answers
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For Synchronisation of DG Sets Sometimes we people use NIC (Neutral Isolation Contactor) Instead of..

Answer / srikanth shreenidhi

Whenever DGs are paralled & synchronised one should have a
common neutral.If neutral of one generator fails
automatically the neutral of other dg sets which is on a
common bus takes over.Whereas if the DG has a 4 pole
breaker and neutral fails it will be impossible for the
system to continue as all the dg sets will have a switched
neutral.
Secondly in case of neutral/contactor failure the user will
have to change only the contactor instead of the whole
breaker

However when only one DG set is used we always go with 4
pole breaker.

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For Synchronisation of DG Sets Sometimes we people use NIC (Neutral Isolation Contactor) Instead of..

Answer / vinod

when a DG set is started and as dg voltage is building up it is necessary to connect the lowest potential point of generator first with the system which it is to be feed, that is the neutral as first. then the breaker can be closed if the set is required to be parallel first. the reason is the system which the DG is intended to supply may have a neutral potential which can be at a different potential other than the DG. so in order to establish a common neutral NIC is used. if NIC is not there and DG neutral is always solidly connected to the BUS then grounding impedance of the whole system is reduced and in turn fault in system can lead to a higher fault current.

Is This Answer Correct ?

9 Yes

1 No

For Synchronisation of DG Sets Sometimes we people use NIC (Neutral Isolation Contactor) Instead of..

Answer / muniraja1283@rediffmail.com

above said subject full very satisfactury

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4 No

For Synchronisation of DG Sets Sometimes we people use NIC (Neutral Isolation Contactor) Instead of..

Answer / zuber ahamed

Is This Answer Correct ?

1 Yes

5 No

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