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biswanath.das
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Can Main Switch Be a Load Break Isolator?

02/05/2012 11:57 PM

Dear Friends,

If one wish to use Havells make DHMIODPX040 Isolator as main switch immediate after residential Tariff Meter of Electricity Board,that is the input to the isolator will be from Meter and output will go to distribution board. Whether this isolator will give short circuit protection or this is just act as a load break switch and will not have O/L or Sckt protection.I don't see any sckt breaking current rating of the isolator in manual. Can anyone confirm.

Thanks

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TonyS
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#1

Re: Can Main switch be a load break Isolator?

02/06/2012 12:44 AM

Normaly off load switching only. Under fault it could have bad results.

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kvsridhar
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#2

Re: Can Main switch be a load break Isolator?

02/06/2012 1:12 AM

Isolators, switches, switch-disconnectors are switched ON and OFF manually. Do you seriously expect them to have a short-circuit breaking capability? This is only possible by devices which can switch off automatically, like circuit breakers.

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sprabakar22
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#3

Re: Can Main switch be a load break Isolator?

02/06/2012 1:19 AM

Dear biswanath as u mentioned its only act as a load break switch.

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mandi
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#4

Re: Can Main switch be a load break Isolator?

02/06/2012 1:45 AM

http://www.electroconcepts.in/havells/PDF/havells_Product_wise_Catalogue.pdf

the given model is an havells MCB (Pg:29 describies )

They are switch disconnectors with independent

manual operation, capable of making, carrying

and breaking currents under normal circuit

conditions, which may include operating

overload condition and also carry currents under

specified abnormal circuit conditions such as

those of short circuit for a specified time....Ref .p30 tech specification....
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biswanath.das
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#6
In reply to #4

Re: Can Main switch be a load break Isolator?

02/06/2012 6:53 AM

O/l Condition automatic trip or manual load breaking capacity?

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PWSlack
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#7
In reply to #6

Re: Can Main switch be a load break Isolator?

02/06/2012 6:59 AM

Well, if it were to have automatic overload breaking capability then it would be called an overload circuit breaker and not an isolator.

Sheesh.

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PWSlack
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#5

Re: Can Main switch be a load break Isolator?

02/06/2012 4:35 AM

It doesn't provide overload breaking. That's why it is called an isolator.

Nor would it. It is the job of individual circuit breakers downstream of it to provide overload protection on the smaller circuit cables. The overload protection on the isolator may well be the utility company's fuse upstream of the isolator.

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Users who posted comments:

biswanath.das (1); kvsridhar (1); mandi (1); PWSlack (2); sprabakar22 (1); TonyS (1)

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