Electrical Question


 
LMichaels

LMichaels

TVWBB 2-Star Olympian
So, due to a failure inside my breaker panel on one lug I nearly had a fire if I'd started my AC unit a couple months back. Well, it manifested as a "failure code" on my smart thermostat prompting me to call the HVAC contractor for repair. Thankfully he found the burned lug in my double breaker before something awful happened. He made a repair, installed a new breaker (yes I could have done this myself but I felt indebted to simply follow through with him)
In any case, he ended by telling my I should not trust it for long.
Well my lifelong friend has extensive experience wiring panels so he said we could do it. BTW we're going to pull out the aluminum feed wire from the meter into the house, replace it with copper with soldered on lugs as well.
On opening the meter housing to inspect what we'd be working with we found the meter lugs incredibly corroded. We're thinking it might be good to give it a spray down with a penetrant ahead of time. WD40 perhaps?
Is there any danger to doing this? If due to WD40 is there something else better to use? Or should we just "wing it" and yank it out?
 
WD40 is a crummy penetrant and/or rust dissolver, IMNSHO. My favorite weasel <BEEEEEEP> is 50/50 ATF & acetone. Something commercial, AeroKroil (HARD to find retail) or PBlaster.

Honestly, I don't think that I'd go hosing down 240v single phase, just for a concern about an arc hazard.
 
JKalchik said:
WD40 is a crummy penetrant and/or rust dissolver, IMNSHO. My favorite weasel <BEEEEEEP> is 50/50 ATF & acetone. Something commercial, AeroKroil (HARD to find retail) or PBlaster.

Honestly, I don't think that I'd go hosing down 240v single phase, just for a concern about an arc hazard.
Click to expand...
By hosing I am assuming you mean hitting with the penetrant
 
DanHoo said:
If the meter lugs are corroded, would that not be responsibility of the power company to replace?
Click to expand...
Yes absolutely but in who's time? The meter was updated to an electronic type not long ago. So, I don't think it would be welded in
 
Larry, just some thoughts and info...

My feeling is that a little penetrating oil should not hurt anything. I would just apply a tiny bit to the corroded threads and not get it all over everything else. Reason being, if things get hot in there due to a bad connection there won't be enough oil to do much in the way of fire.

Is it just the set screws that are corroded? Or did the corrosion get into the block where the wire goes? How do the the supply (hot) terminals look? are they corroded too? It would worry me if the lug blocks or meter "stab" contacts are corroded. As you probably know, a bad connection here will get hot and fail.

Are the lug blocks aluminum? If so, part of me says aluminum wire in an aluminum lug might actually be better than copper wire in that aluminum lug. That way, there are not dissimilar metals outside in the meter box. I'm sure the guy will use No-Al-Ox or something similar on the aluminum wire, if you go that way.

Carefully check and make sure there is no water getting into the meter box. Some SE cable fittings rely on a big blob of putty (specially made for the purpose) at the top connection where the SE cable goes in. The putty dries out, shrinks back, falls off - fails - and now water can get in. Sometimes the water just harmlessly passes through and drains out the bottom. But sometimes it gets into the sheath of the SE cable that exits the bottom of the box and follows that into your breaker panel - not good.

Most breaker panels I've wired have lug blocks on the bus bars - or if the main breaker is in the panel it will have its own lugs so there might not be any need to install lugs on your new feed wire at all.
 
I owned an electrical contracting business for about 20 years.
One of my employees did not use the dope for aluminum 220 wires and near cost me a large claim.
A bad connection will increase resistance and will get hot.
Sometimes you can actually smell it and know it wrong
The dope (aluminum wire bonding agent) along with a tight connection eliminates this.

As far as the burned lug goes,
You can pick up and use some electrical cleaner but the question is what caused the heat?
Have you figured that out yet?
Can you see the bonding agent on your aluminum wires?

For your wire pull use electrical pulling soap if you are pulling through EMT or some kind of conduit.
It’s a goop that drys into a powder (ish) non conductor.

Am I understanding your question?
 
Larry: this makes me nervous, I suppose because I don't understand electrical work. I hope everything works out safely and effectively.
 
My father used to say, “Electricity is like magic and that not something I fool with!”
Unless it’s something very basic, I feel the same way!!
I had a strange thing happen once too very involved and too wordy to type but, it stumped a whole raft of very very qualified electricians(4)! They were all scratching their heads, none had ever seen anything like it!
 
For the record. The guy that came out to repair the AC said the one burned lug in the breaker panel is somewhat common. I spoke to a commercial electrician I am friends with at church and he told me the same (though he did not want to do it because he doesn't do residential), I tried to hire the electrical branch of the company who did the HVAC, they came out, measured and all. Never heard from them again. Summer heating up a bit, wife needing to go in for another surgery, was cautioned to run AC sparingly.
My lifelong friend is experienced and has done much of this type work. The aluminum in there now is between then meter and my main breaker. It appears intact, but since we're adding a second (in parallel) 100 amp panel we're going to pull new service lines in for both boxes of copper. This will give me 200 amp total service. Ideally I would have simply installed a replacement 200 amp box. But the way it's shoehorned into the studs and the bottom and top rim joists there is no room to add a larger panel in there. And without puling all new circuits in the house I cannot even surface mount a new panel. The stupid original "electrician" (totally sloppy, awful work), did not leave enough wire in place. So, we're having to flush mount a second panel right next to it. Hard to explain I'll try and do a photo. But here is a photo of the mounting socket for the meter. Pretty corroded. You can see the top 2 lugs. So, I was hoping it would be safe to spray it with a bit of penetrant and allow to sit until Monday is all. This was my hope. Simply to make yanking out the meter easier.
1722689864521.jpeg
 
LMichaels said:
So, due to a failure inside my breaker panel on one lug I nearly had a fire if I'd started my AC unit a couple months back. Well, it manifested as a "failure code" on my smart thermostat prompting me to call the HVAC contractor for repair. Thankfully he found the burned lug in my double breaker before something awful happened. He made a repair, installed a new breaker (yes I could have done this myself but I felt indebted to simply follow through with him)
In any case, he ended by telling my I should not trust it for long.
Well my lifelong friend has extensive experience wiring panels so he said we could do it. BTW we're going to pull out the aluminum feed wire from the meter into the house, replace it with copper with soldered on lugs as well.
On opening the meter housing to inspect what we'd be working with we found the meter lugs incredibly corroded. We're thinking it might be good to give it a spray down with a penetrant ahead of time. WD40 perhaps?
Is there any danger to doing this? If due to WD40 is there something else better to use? Or should we just "wing it" and yank it out?
Click to expand...
Larry - I am not familiar with soldered lugs for copper when used as the SER between the meter and the panel. This does not sound right. My only experience with soldered copper wire is for low power electronics. Perhaps things are different where you are. Just saw your meter picture and quite different than what we have here in Northern Va and MD.

All of our new construction homes for my entire career (25+ years) have been aluminum SER with NoLux applied. The meter cans around here vary by power company. Most meter cans have female lugs (terminal blocks) were the bare wire with Nolux are inserted and the screw tightened. Example 400A meter can in the middle in the picture below (utility connection not made at time of picture).
1722690059650.jpeg

There are some meter cans where there are male threaded terminals which require a lug. When lugs are needed, the electricians use a hydraulic press to crimp the lug to the wire. The electrical supply houses here will use their hi-press machine to terminate the SER at time of purchase for a nominal fee.

Here is the 200A meter base at my house. You can see the hi-press lugs on the left going to the house panel and the indents from the press are quite noticeable. This is a 1987 installation and you can see the NoLux that was applied at the crimps has oozed out some. Lethal utility wiring on the right with just a thin shield between L1 and L2. I just happened to be home when they installed a smart meter so was able to see inside.

Should go without saying, but one by one, kill each breaker in the panel and then kill the main last before attempting removal of the meter. You will need to cut the safety seal and figure out how to get a new one.

1722689833519.jpeg
 
It’s interesting to see the regional variations in play. Here in Upstate NY, things are a little different as the meter socket is not provided by the utility. It is the responsibility of the homeowner to furnish and install all equipment and wiring beyond the riser cap for overhead or up the pole for underground for the utility to connect to. I spent 20+ years in the field as a sparky and can count on one hand the number of times we used copper for any residential service entrance runs. Properly prepared aluminum conductors are more than suitable for the purpose. @Wilmer Cogburn obviously knows what he’s doing and also knows how to articulate it properly. There’s not a single hint of an inaccuracy in any of his shared thoughts. Well done and well said, good sir!
 
Following this thread with interest !
Ex C-10 (california) contractor back in the 80s (while also working @ 3m as an electrician)
only industrial, never residential !
 
LMichaels said:
For the record. The guy that came out to repair the AC said the one burned lug in the breaker panel is somewhat common. I spoke to a commercial electrician I am friends with at church and he told me the same (though he did not want to do it because he doesn't do residential), I tried to hire the electrical branch of the company who did the HVAC, they came out, measured and all. Never heard from them again. Summer heating up a bit, wife needing to go in for another surgery, was cautioned to run AC sparingly.
My lifelong friend is experienced and has done much of this type work. The aluminum in there now is between then meter and my main breaker. It appears intact, but since we're adding a second (in parallel) 100 amp panel we're going to pull new service lines in for both boxes of copper. This will give me 200 amp total service. Ideally I would have simply installed a replacement 200 amp box. But the way it's shoehorned into the studs and the bottom and top rim joists there is no room to add a larger panel in there. And without puling all new circuits in the house I cannot even surface mount a new panel. The stupid original "electrician" (totally sloppy, awful work), did not leave enough wire in place. So, we're having to flush mount a second panel right next to it. Hard to explain I'll try and do a photo. But here is a photo of the mounting socket for the meter. Pretty corroded. You can see the top 2 lugs. So, I was hoping it would be safe to spray it with a bit of penetrant and allow to sit until Monday is all. This was my hope. Simply to make yanking out the meter easier.
View attachment 97194
Click to expand...
The existing meter can will need provisions for 2 sets of SER so you can feed 2 100A panels in parallel. Not all meter cans have this.

Will your existing secondary from the transformer to your house accommodate a service upgrade to 200A? If not I see this as a problem.

Here we call this a “heavy up” and it’s coordinated by the power company and inspected by the local AHJ as well. Permits are involved.

Service upgrades here sometimes require additional work such as upgrading circuits to arc-faults, etc.

Be careful.
 
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