Who could've known?

[DavidA]

Who could've known that shoving the neutral of a 200A 3 phase feeder into the lug and forgetting to properly torque it down would cause any trouble? It was good enough to last a few years right? No big deal. Sheesh. Least the office being served got a free test of all their surge protectors. Few casualties.

 

[LarryFine]

Well, don't stop there! :roll:

 

[jeremysterling]

Well, don't stop there! :roll:

I agree. Stopping there is a little like stripping the wire, shoving it in the lug, walking away to find your hex keys, and... well, never coming back!

 

[GUNNING]

It wasn't me!!

It wasn't me!!

I see loose neutrals all the time. I had a service call the night before last for blinking lights. It was a loose 14 gauge neutral in the panel of a Mobil Home .. uh modular manufactured housing.
I had another electrician follow up behind me on a service call at a kitchen. He said that there had been a bunch of lose connections. It never occurred to me to check. I do now. I find loose lugs all the time and not just the discolored ones from heat.
I'm really careful with those shiny aluminum lugs. When new they will cross thread. It feels like you've got it but when you wiggle the wire its loose and cross threaded. When installing Ill test drive the lug and if It feels grainy put some WD40 or some nolox on the threads. I try to run them up and down and debur them before putting the wire in.
I went to a Mike Holt seminar a while back and he said its the lugs on the left don't get tightened as much as the ones on the right. Its because most people have a dominant stronger right hand. I guess a torque wrench would work but that would be one more thing to clean and keep track of. Besides, if you cross thread the lug it won't matter.

 

[shepelec]

Glad I'm a "lefty".

I use the nolox trick on all lugs.

 

[GUNNING]

manufactured defect

manufactured defect

That just means your right side will be loose.

Why isn't there a book out there with these tricks.

 

[Howard Burger]

because of the contributors here!

because of the contributors here!

A book? There doesn't need to be one. The electricians out there that want to improve watch this site. Nolox on neutral screws, huh? Neat idea.

 

[PetrosA]

I had a call on Friday that a breaker had started tripping in an off-campus house. I've had these before in the winter where the kids all started plugging in portable heaters, but these girls seemed pretty reasonable. Turns out it was an older Siemens panel and the 15A breaker the circuit was on had a funky terminal that allowed the wire to slip sideways as you tightened the screw down. the wire was pinched enough in there that it felt tight until you really started to wiggle it around. I'm sure the installer didn't know, as it took me at least three tries to get the wire under the screw. Ultimately I had to pop the breaker out and do it where I could see whether the wire was in place or not. Awful design.

 

[DavidA]

Judging by the meter stamps the neutral in question would be very difficult to tighten down as the neutral bus runs perpendicular to the fuse blocks and another office would have to have been shut down and disconnected from it's fusible pull out to gain full access. Bad design or bad decision on the part of that installer?