Todays' Service Call (Solve this service call)

[Russs57]

Sounds like a business opportunity. He has an electrical service ill suited to his single phase loads. He has no grounding/ bonding system. He very nearly had a fire. It needs to be changed. Either get a bunch of 3 phase equipment.......or switch to 120/208 wye.

If he stays with the high leg delta service things to be marked and laid out in such a way that nobody can add 120 volt loads to high leg.

 

[480sparky]

Sounds like a business opportunity. He has an electrical service ill suited to his single phase loads. He has no grounding/ bonding system. He very nearly had a fire. It needs to be changed. Either get a bunch of 3 phase equipment.......or switch to 120/208 wye.

If he stays with the high leg delta service things to be marked and laid out in such a way that nobody can add 120 volt loads to high leg.

Here's the hilarious part. There are 7 1-pole breakers on the 214V B leg.

They read either 117 or 122 volts however. Strangest thing I've ever seen. 214v on the bus, but 117 or 122 at the breaker terminal. I would have relocated them, but all 30 spaces are filled up so I just let sleeping dogs lie.

But yes, I'm working up a price to change this over to a 1-phase 40-space panel. No other customers will be affected by the change in transformers because there are no other services on them ('cept for some 240v street lights, but that's not an issue).

 

[kwired]

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And an answer I alluded to right from the start. Post 5.

You just wanted to see how many guesses at the problem would be mentioned. If you showed those thermal images in post 1 most would have said there is a problem somewhere on that neutral assembly.

Here's the hilarious part. There are 7 1-pole breakers on the 214V B leg.

They read either 117 or 122 volts however. Strangest thing I've ever seen. 214v on the bus, but 117 or 122 at the breaker terminal. I would have relocated them, but all 30 spaces are filled up so I just let sleeping dogs lie.

But yes, I'm working up a price to change this over to a 1-phase 40-space panel. No other customers will be affected by the change in transformers because there are no other services on them ('cept for some 240v street lights, but that's not an issue).

Older panel that can have the breaker "fingers" easily moved to a different main bus? Might have needed an extra panel to rob them from though as the one's from center bus only work on center bus.

 

[480sparky]

You just wanted to see how many guesses at the problem would be mentioned...

Please stop assuming you know what I wanted. I want to help TEACH OTHERS about what goes on at a service call. Nothing more. Live with it.

If you showed those thermal images in post 1 most would have said there is a problem somewhere on that neutral assembly....

Sorry, I didn't get them until this morning. Again, live with it.

...Older panel that can have the breaker "fingers" easily moved to a different main bus? Might have needed an extra panel to rob them from though as the one's from center bus only work on center bus.

I could, but it would be far better to match a new service to the customers' electrical needs.

 

[kwired]

Older panel that can have the breaker "fingers" easily moved to a different main bus? Might have needed an extra panel to rob them from though as the one's from center bus only work on center bus.

I intended this to be asking it that is what was existing, being the reason you didn't have high leg voltage on high leg positions? Did you pull breakers to see if there was bus modification or did you just measure voltage at main lug/breaker on center leg? Older QO and CH loadcenters was easy to reconfigure bus to breaker if one wanted to.

Please stop assuming you know what I wanted. I want to help TEACH OTHERS about what goes on at a service call. Nothing more. Live with it.

Well what goes on is if an experienced person sees that neutral assembly is showing excessive heating - they address it before trying to figure out some of those less likely scenarios that you let continue on when you knew the neutral assembly was heating up.

This is why it was asked a couple times if you had solved the problem or were still looking for possible solutions, it seemed at the time you either didn't know what was going on or was holding back some information that would have made the problem more obvious.

 

[romex jockey]

Please stop assuming you know what I wanted. I want to help TEACH OTHERS about what goes on at a service call. Nothing more. Live with it.

Live it indeed...excellent thread!

It's often a chore to approach such debaucheries methodically , one tends to wonder what the former spark was thinking (if there was one at all) .....yet the fundamentals of sparktrickity still apply

~RJ~

 

[Russs57]

Looking at the IR photos I’d want to pull meter base and meg. Maybe just replace wire if short enough. Maybe restrip and re-land all neutrals.


PS, why call them noddles? Some reason like it is high leg delta?

 

[kwired]

Looking at the IR photos I’d want to pull meter base and meg. Maybe just replace wire if short enough. Maybe restrip and re-land all neutrals.


PS, why call them noddles? Some reason like it is high leg delta?

Meg what? the neutral bus?

Megger is for measuring high resistances, here we want low resistances.

 

[jumper]

PS, why call them noddles? Some reason like it is high leg delta?

Simple.

Noodle is easier to spell than neutral.

 

[480sparky]

Live it indeed...excellent thread!

It's often a chore to approach such debaucheries methodically , one tends to wonder what the former spark was thinking (if there was one at all) .....yet the fundamentals of sparktrickity still apply

~RJ~

There was a sticker on the cover from another local EC. Makes me wonder if the owner got taken.

 

[growler]

There are 4 conductors. It is a 3-ph panel with a high leg.

Here's the hilarious part. There are 7 1-pole breakers on the 214V B leg.

They read either 117 or 122 volts however. Strangest thing I've ever seen. 214v on the bus, but 117 or 122 at the breaker terminal.

214V on the buss and 117-122 at the breaker terminal ?

If I find something like that I'm calling in a priest to perform an exorcism and cast out the demons.

Are you sure that section of buss (to the high leg) has not been disconnected ? I really don't believe in demons. Maybe that buss has been disconnected and feeds back or has been jumped to another phase.

 

[Russs57]

Kwired, meg wiring from panel to meter base to make sure insulation hasn't been compromised from long term overheating. I’m betting this has been going on for awhile. Had the AC not tripped a breaker, and story gotten sideways, nobody would have had that panel cover off.

 

[480sparky]

214V on the buss and 117-122 at the breaker terminal ?

If I find something like that I'm calling in a priest to perform an exorcism and cast out the demons.

Are you sure that section of buss (to the high leg) has not been disconnected ? I really don't believe in demons. Maybe that buss has been disconnected and feeds back or has been jumped to another phase.

There were two 1-p breakers that didn't have anything connected to them. Turn them on, and I'd get 214v on the terminal. But the other 7 that were loaded only showed 117 or 122.

 

[growler]

There were two 1-p breakers that didn't have anything connected to them. Turn them on, and I'd get 214v on the terminal. But the other 7 that were loaded only showed 117 or 122.

Did you turn off the breaker, disconnect the load and then turn the breaker back on and then measure voltage ? What do you get when you measure to another phase, the breakers on either side of it ?

I'm sure this serviced is totally rigged but there still must be a reasonable explanation. I can't think of any way those breakers could account for that kind of voltage drop.

 

[peter d]

The problem is too much impedance somewhere.

 

[480sparky]

Did you turn off the breaker, disconnect the load and then turn the breaker back on and then measure voltage ? What do you get when you measure to another phase, the breakers on either side of it ?

I'm sure this serviced is totally rigged but there still must be a reasonable explanation. I can't think of any way those breakers could account for that kind of voltage drop.

Once the arcing and overheating were solved, it was time to get outta Dodge.

 

[drcampbell]

... PS, why call them noddles? Some reason like it is high leg delta?

I suspect it was originally low comedy.
But I've taken to using it occasionally -- and almost never using the word "neutral"; usually "white" -- because the white wire is only neutral if the load on all the phases is balanced, which is almost never the case.

 

[romex jockey]

I suspect it was originally low comedy.
But I've taken to using it occasionally -- and almost never using the word "neutral"; usually "white" -- because the white wire is only neutral if the load on all the phases is balanced, which is almost never the case.

well the definition didn't exist until (IIRC) the '08 cycle , what were we 'spose ta do ?

~RJ~

 

[LarryFine]

I'm guessing someone has already "re-fingered" the breaker contacts away from the high leg for those 7 breakers.

 

[kwired]

Kwired, meg wiring from panel to meter base to make sure insulation hasn't been compromised from long term overheating. I’m betting this has been going on for awhile. Had the AC not tripped a breaker, and story gotten sideways, nobody would have had that panel cover off.

That makes a little more sense now that you mention that, though I think the heat damage would have all been at load end where that poor termination was, and it looks like with bottom feed and lugs apparently at top, any insulation damage with heat originating at that terminal should be visibly obvious, and should lessen the further away you get from the terminal. 6-8 inches away likely never got heated enough to cause any insulation damage.

I'm guessing someone has already "re-fingered" the breaker contacts away from the high leg for those 7 breakers.

I tried to mention this twice, but you are the only one that gets it that this is even possible, was easy to do with older QO panels and CH panels.