HIPOT TEST

[Parchie]

Y'all,
Just a question here. A contractor is going to do a cable hipot testing and client wanted to cut testing time.
Q: Is there a big difference between:
1) shorting the source side of the conductors (3 conductors) when doing the hipot and shorting the load side end also, versus
2) having the source end lumped and load side conductors open?
(All shield wires are lumped and grounded at both ends)

 

[che12345]

Dear Mr Parchie

1. There is no differences between method 1) or 2). I was unable to locate any references that
state the other end conductors [shall] be shorted during the test. The usual practice is as 2)
i.e. with the other side conductors [open]. It is not harmful but superfluous to short the other
conductor ends.
Caution: Discharge the conductors thoroughly before removing the shorting, if applied !

2. The proposed method i.e. by shorting all three line conductors with respect to the earth:
a) is time saving but has the disadvantage that the (integrity between the three conductors) is
[not verified]. It is based on the assumption that any defects (between the three conductors)
would show out as [each conductor is shielded].
b) would need a test set with sufficient (trip) current capacity; even-though the withstand
voltage, (not) the (leakage) current is the passing criteria. Test with dc instead of ac may
circumvents the limitation.

Che Kuan Yau (Singapore)

 

[Parchie]

Thanks a a lot. Client opted to individually hipot the cables, the usual way!