grrrrr

I was called to a house to look at a problem with the lights. It turns out that when the furnace kicked on the lights would dim. The same problem occurred when the coffee pot was used. I walked down to the basement and removed the cover on the panel. The thing was full of new breakers, but the main breaker was old and the connections were so rusted that I couldn't even see the screw head on the lugs. When I reached up and touched it half the basement lights went out and I could see arcing behind the main breaker. After a little talking I found out that the basement had flooded full of water about 20 years ago and the panel had not been replaced. Several days later I showed up to replace the entire panel and all went as expected. However by the time that I was finishing I was pressed for time to get the boys from school so I gave it a quick once over to make sure things worked and everything seemed OK. Got a call a few days later that the problem persisted. When I went back I checked voltage on the main lugs. I found 134 volts on A phase and 114 volts on B phase to ground. Classic case of the incoming neutral gone bad. After double checking my work I pulled the electric meter outside and all connections seemed good. At that point I called the power company and they said they would take care of it.
The lineman called me later and we compared notes and all seemed OK. That is until today when I got another call and the problem persisted. When I went back today I finally fount that the neutral connection in the meter socket was bad. There were 2 #4 SE cables, 1 supply and 1 power to panel, and the neutrals were behind a metal "washer"
Apparently one of these neutrals was thicker than the other and held it out so that the load one was making a poor connection. Since this was an old meter socket there was next to no room to work and just a PITA but that seems to have fixed it. How can something so simple get missed so many times? Maybe stranger still is how did this not happen in the previous 30 years since it was installed, and how did that wet breaker work for 20 years?

I hope you have it licked.

I have had breakers and supply lines that worked for years that when I tore into them I did not see how they EVER worked at all. There used to be a lot of rigged up electric panels around.

Almost identical to last weeks voltage variation. Good effort payed off. Jim

At least it is fixed.

Yeah, I hadn't thought of that. Like most things there wasn't enough time to do it right the first time...

Yeah, really makes you wonder sometimes. Then the next time you build something bulletproof and it won't last a week. Keeps people humble I guess

I"ve seen this scenario more times than I should have had to, over the years. A bad/broken/poorly connected neutral is NOT a good thing!

Wow, I didn't realize there were so many electricians on this forum.

Can I pick someone's brain?

I want to bury a line to my 2 (soon to be 3) shops. The first shop is about 200 feet away, next is 300 feet away.

I have installed a 100 amp square d panel in the one shop. It's the QO line, not homeline. I need to dig a ditch, bury conduit, and hire someone to tap in and pull the line through.

Should it be tied in at the electric meter? at my house panel? install another meter from the transformer?

Should I put a 200 amp panel in the first building, then run the line to that building, then use the 100 amp panel as a sub panel in the other building, with just a line from one building to the other, and then another separate line to the next building? The newest building being built will just have fluorescent lights and electrical outlets, not heat or anything else. So, can I then run a line from the 100 amp panel to the new building? What are the limitations on total use? Right now, I run building #1 on a single 60 amp breaker from my house panel, with a buried line that is maybe 10-3 or 8-3, I can't remember. I have an extension cord running across the driveway into building #2 to run one dusk to dawn light. I buried 2 inch gray pvc conduit in the concrete from the 100 amp panel and it has a 90 degree elbow with a plastic bag shoved in it, before I filled the hole.

I drew a picture.



What should I do?

(quoted from post at 05:49:25 03/02/14) Wow, I didn't realize there were so many electricians on this forum.

Can I pick someone's brain?

I want to bury a line to my 2 (soon to be 3) shops. The first shop is about 200 feet away, next is 300 feet away.

I have installed a 100 amp square d panel in the one shop. It's the QO line, not homeline. I need to dig a ditch, bury conduit, and hire someone to tap in and pull the line through.

Should it be tied in at the electric meter? at my house panel? install another meter from the transformer?

Should I put a 200 amp panel in the first building, then run the line to that building, then use the 100 amp panel as a sub panel in the other building, with just a line from one building to the other, and then another separate line to the next building? The newest building being built will just have fluorescent lights and electrical outlets, not heat or anything else. So, can I then run a line from the 100 amp panel to the new building? What are the limitations on total use? Right now, I run building #1 on a single 60 amp breaker from my house panel, with a buried line that is maybe 10-3 or 8-3, I can't remember. I have an extension cord running across the driveway into building #2 to run one dusk to dawn light. I buried 2 inch gray pvc conduit in the concrete from the 100 amp panel and it has a 90 degree elbow with a plastic bag shoved in it, before I filled the hole.

I drew a picture.

What should I do?

Click to expand...

I am not an electrician but I will make two observations: First when laying a pipe for utilities always put in an extra because you may want to add something later, and often you can't put it in the pipe with something else. Second, I am on the downsizing side and I would love to have my three buildings on one meter in order to eliminate the basic charges that I am now paying on both services even though use is very low. I think that I would see if I could put a heavier line in the pipe from the house and see if I could run all four from a 200 in building one.

If it was me, I would run it from the
meter If the situation is right. The main
reason bring that it is not much further
and it is easier to bring a conduit up
into the meter. The meter needs to have
separate places for the extra wire, you
cannot put two wires in one hole unless it
is rated for it. Another consideration is
being able to avoid buried lines near the
meter, phone, elec, gas, cable, etc.
That being said, I would run a minimum
1/0 size wire to the first shop and then
feed off of that first panel to fed the
other sheds.

Showcrop,

That would be ideal, but, I am pretty sure we used 3/4 inch or 1 inch black plastic waterline as conduit when we put the service into the first shop in 1997. I agree it would be best to have it all on 1 meter.

Greg,

If the meter doesn't have a place to put another wire in, can the power company change the meter? If I run the wire in 2 inch conduit, from the meter, I will have to make a few turns in the ditch. how hard is it to pull a line through with bends in it? Maybe I can stare at it for a while and figure out a way to run it under the front porch, attached to the house for the final 30 feet, instead of making a turn. Is there a certain 200 amp panel I would have to buy that will allow me to run a wire in, and then out to the next building? 1/0 from the 200 amp panel to the 100 amp in the next building?

Thanks for the advice.

I remember many years ago in Bay City, MI I went on a heat out service call. I brought in my light probe and showed juice to everything. I then got my VOM and found out one of the screw fuses was only letting 25 volts through it. When I unscrewed it and looked at it real carefully, you could see a slight smudge on one side of it. Replaced the screw in fuse, and the furnace took off, all systems, go. Even Pipefitters have to know electricity.

Greg,

while I am thinking of it...


What would you use? URD aluminum triplex?

Does the wire need to carry a ground if is going to be as a sub panel from one building to the next? I think 500 foot spools is the least I can buy. If you were using a 200 amp panel would 4/0 wire be best?

Thanks again for letting me pick your brain. I used to have a book with all the ratings before the flood. I should buy another one.

OK, the 1/0 was figuring for voltage drop
on a 100 amp panel. If you want to go to
200 amps that is a minimum of 4/0 aluminum
or 3/0 copper. With 200 amps I wouldn't
worry about voltage drop since you will
probably never come close to using all of
that power. Yes I would use direct bury
rated aluminum cable. I also would put it
in PVC conduit to protect it but that step
is not necessary. If you use large radius
90° bends it will pull in easier, I
believe they are 36" radius bends. Panels
in the sheds that feed off of the first
shed are considered sub panels and need to
have the grounds and neutrals kept
separate and need a separate ground and
neutral wire run to them. Assuming there
is room under the meter you could try
putting a large PVC junction box under the
meter and, using gutter taps, splice off
to the house and shed while leaving the
meter in place. You can usually buy wire
cut to length at a wholesale house or big
box store. Also make sure to check local
rules and regulations since they can vary
widely from one place to another. Your
best bet may be to check with a local
electrician and see if he is willing to
work with you on some of this stuff.
If you still want to come out of the house panel then I would not figure on using more than a 100 amp panel since it will be very difficult to feed 4/0 out of a regular panel. If someone else has ideas I hope they will join in.

Greg,

Thanks for all the help. I'm sure I can figure something out. Going from the meter seems like the way to go.