Burnt Neutrals in panel. Any ideas?

[Pantron]

Any Ideas what might cause these burnt Neutrals? This is in a breaker box connected to a large road sign. It has been converted to LED. Customer states The breakers kept tripping and found burnt neutrals.

Both breakers are tripping. One in the Franke box and one on the breaker panel, AP number one.

Their electrician said that’s because of a problem up in the sign. Customer states his electrician "checked the breaker itself and it is fine."

 

[AC\DC]

Well first thing to do is to figure if those neutrals are part of a multi-wire-branch circuit and if so, that each phase conductor is on separate phases. If they are own the same phase they will compound their return current on the neutral and cause that.

From the looks of the picture and the mess that is probably it.

 

[retirede]

It appears that the heat emanates from the neutral bar connection. Loose connection and/or corrosion.

 

[AC\DC]

could be that also.

 

[Hv&Lv]

How many neutrals are doubled up under the screws?

Also, what exactly is that bar bonded to??

 

[Seven-Delta-FortyOne]

Possibly high non-linear load and/or common neutral.

Especially if they just converted it to LED.

 

[AC\DC]

From my limited knowledge don't most Non-linear loads have filters on them now to prevent harmonics.

 

[ptonsparky]

Overloads. PP connections due to improper termination, corrosion. Excessive heat in the enclosure causing thermal trip, etc. Time for a new panel and breakers.

 

[Ponchik]

By the look of that larger lug I would guess it is a combination of moisture and loose connection. Clean up the neutral conductors and use a fresh slot. Then turn the load on and check for current flow and see if they within spec.

 

[Jon456]

That large lug on the neutral definitely needs correcting. But it seems to me if that was the only problem (corrosion/loose connection), then the burning would be limited to the wire under that lug. I don't think it would explain the severe burning of the other wires on the neutral bar.

 

[hbiss]

All I see is corrosion in the bottom picture. I have no idea what the top picture is of. Looks like hots overheating there.

I agree. Clean it up, turn it on and check the current draw. I do think though the bottom panel should be replaced.

-Hal

 

[kec]

I say if the neutral wire is burnt at the termination point then its a loose connection.

Also loose at the feed point on the din rail connection. You have to be sure you get the wire under the lug and tight.

sometimes difficult with european relays.

What a mess. Redo it.

 

[robertd]

The screws on the two unused breakers just above the neutral bar look corroded. That panel needs to be replaced.
In the upper photo what are the din rail items, connectors, relays? On the lower set of screws, fourth over from the left it looks like the conductor has overheated, and the right side of the left din device looks like it has overheated.

 

[jaggedben]

I recognize the Murray/Siemens four space panel in the bottom picture. There are too many neutrals on that bar. 10 neutrals on the bar and no more than 5 hots on breakers in that panel. There are some serious wiring errors on this site. Good luck.

 

[growler]

I do think though the bottom panel should be replaced.

-Hal

There may be other problems but I agree that replacing the bottom panel is a good place to start.

 

[Dennis Alwon]

Look at the top pic. The left side signage unit is brown also. You need to do a total rework of all the work shown. I also am not sure about those conduits on the right getting a good connection to the box with the label there.

 

[Jraef]

From my limited knowledge don't most Non-linear loads have filters on them now to prevent harmonics.

Not yet. It’s a requirement in other countries, but here it is “voluntary” so bottom feeder suppliers sometimes take advantage in order to capture the price shoppers.

 

[AC\DC]

Not yet. It’s a requirement in other countries, but here it is “voluntary” so bottom feeder suppliers sometimes take advantage in order to capture the price shoppers.

Really. I would of thought it would of been other way around. Thanks