[Neda]

I have a three phase – 4 poles ELCB (earth leakage circuit breaker), can I use it for protection of single phase circuit?
I have a three phase – 4 poles ELCB (earth leakage circuit breaker), can I use it for protection of single phase circuit?

Topic

[Hamid]

Regardless some sensitivity or setting ability concerning, you can use 4 pole ELCB in single phase circuit by suitable jumper on its terminals. See some wrong and correct connections in below:

[V.K.Nambiathiri]

May please explain why first two connections are wrong

[Hamid]

In first connection, the thermal over load of each individual phase face to 1/3In, therefore the ELCB setting will not correct. In second connection, the balancing of mmf which designed to detection of earth fault is not established in normal loading conditions without any faults; because 3i-i is not zero.

[V.K. Nambiathiri]

1. In ELCB, thermal O/L are not required as it is not intended to give O/L protection. Then what is wrong in first connection 2. In second connection 3i-i-In is balanced at healthy condition. I feel second connection is also correct Please clarify

[Hamid]

1- MCB+ELCB combination conforms to international standards like VDE 0664,CEE 27,SS97,IEC 898, BS4293, IEC 1009 , please note to following typical catalog. 2- 3i-i=2i which is not zero, therefore ELCB involve to mal-function in normal loading.

[V K Nambiathiri]

Please clarify your statement

[Author]

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