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Martin.Leith
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Difference Between TPN & 4P

08/06/2012 2:48 AM

please explain the difference between TPN and 4P mcb protection
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PWSlack
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#1

Re: difference between TPN&4P

08/06/2012 3:30 AM

What difference?

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TonyS
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#2

Re: difference between TPN&4P

08/06/2012 4:34 AM

4 pole all the contacts open simultaneously. 3Ph + N there is a slight delay before the neutral opens.

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electricalexpert65
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#3

Re: Difference Between TPN & 4P

08/22/2012 10:38 AM

In TPN (three pole + neutral) breakers, only three phase poles would have the releases (thermal & magnetic) and the fourth neutral pole is only a switch without any releases in it. Whereas in four pole breakers, all the four poles would have releases.
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