Testing into open breaker with line energized.

[tcoupekyle]

So this is something I just thought to be pretty much standard practice. Don’t Meg cable into a breaker with an energized line side.
Today I was asked where it says this. I was like you can’t test a component that has any part energized per NETA. But I kinda wasn’t sure.
Anyone know where the literature is to back this up?

[tcoupekyle]

Or maybe I’m just wrong and it’s perfectly fine.

[SecondGen]

So this is something I just thought to be pretty much standard practice. Don’t Meg cable into a breaker with an energized line side.
Today I was asked where it says this. I was like you can’t test a component that has any part energized per NETA. But I kinda wasn’t sure.
Anyone know where the literature is to back this up?

It probably goes against all modern safety practices but I've done it before in situations where I felt comfortable. Not sure NETA calls this out specifically but I doubt they would endorse the practice.

[tcoupekyle]

It probably goes against all modern safety practices but I've done it before in situations where I felt comfortable. Not sure NETA calls this out specifically but I doubt they would endorse the practice.

I’ve done it too… just always thought I was taking a short cut and thought it was definitely like a no no.

But never had anyone ever ask about it in particular until today.

[SecondGen]

I’ve done it too… just always thought I was taking a short cut and thought it was definitely like a no no.

But never had anyone ever ask about it in particular until today.

I suppose technically its a shortcut but one situation I remember was newly repaired cable in a LV switchgear, which had been re-energized by time we arrived to test. For whatever reason they couldn't get another outage so we made it work.

[tcoupekyle]

I suppose technically its a shortcut but one situation I remember was newly repaired cable in a LV switchgear, which had been re-energized by time we arrived to test. For whatever reason they couldn't get another outage so we made it work.

Yeah always been similar situation. On 480v or less. I don’t think I’d dare do it on anything higher voltage.

[TestingProToBe]

Yeah always been similar situation. On 480v or less. I don’t think I’d dare do it on anything higher voltage.

I haven’t ever seen anything specific about not doing a test like that but it’s definitely not an ideal situation.
And I don’t think Neta would be the place you would find that such a passage. I’d think nfpa70e might have something but they will probably just tell you about PPE required to perform that action. If you find something let us know!

[alf583]

So this is something I just thought to be pretty much standard practice. Don’t Meg cable into a breaker with an energized line side.
Today I was asked where it says this. I was like you can’t test a component that has any part energized per NETA. But I kinda wasn’t sure.
Anyone know where the literature is to back this up?

I don't recall seeing it in print. My company "forbids" testing with anything energized. It sounds like a common, unwritten safety practice. I'm fairly new though so I may not have come across the written rule yet.

Like other folks said, if you're comfortable and confident then go for it. Be safe!

[JamesM]

I've done this in an old substation, we were testing single conductor cables that were terminated to a switch that was open the other side was hot at 13.8kV line.

I was told to reduce the test voltage - AC in case we had opposing wave forms. I forget the test voltage, but I was told that if we are testing at 15kV then opposing waves (one from the test set vs system voltage) could be approx. 23kV across the switch.

It may be that the insulation, in this case air, might not be enough to handle the extra voltage.

- as a caveat, I was very new to testing at the time and acted under the advice of my superiors.

[nowwearesuckingdick]

So this is something I just thought to be pretty much standard practice. Don’t Meg cable into a breaker with an energized line side.
Today I was asked where it says this. I was like you can’t test a component that has any part energized per NETA. But I kinda wasn’t sure.
Anyone know where the literature is to back this up?

Reading Megger/AVO's "A Stitch in Time", they say to not test energized equipment and one side of a switch, breaker, etc being energized and you testing the other side, that should still be considered energized equipment. I imagine that the user manual for the test equipment being used probably also advises against testing into hot equipment. If the load side fuses, bus, cables, etc of said "line hot" equipment was completely disconnected and electrically isolated from the "line hot" equipment in addition to the control device itself being open and locked out, then I would consider that an electrically-safe work condition which is absolutely positively addressed in NFPA70E. Otherwise, it's a NO!