[sjh]

This is my first post so hope I’m in the right place. If not, please let me know where I should be posting.

My wife and I inherited a 37 year old house that we’re planning to fix up as a rental. I noticed a porcelain light fixture in the unfinished furnace/laundry room was broken. It didn’t have a light bulb in it; the box it was fastened to was being used as a junction box for 2 florescent light fixtures in the same room. There are wires coming in from 2 3-way switches, wires to the 2 florescent lights, and a hot wire continuing elsewhere in the basement. I decided to remove the broken fixture and just put a cover over the box and let it serve only as a junction box. I turned off the 15 amp breaker for the basement area, removed the light and started to reconnect all the white wires together. I suddenly got a small shock. I probed the area with my insulated pliers and saw a tiny spark when I touched 2 of the white wires. I got nothing from the other 3 white wires. Thinking I must have a bad breaker, I then turned off the main breaker and checked the wires again. I still got the tiny sparks when I touched the wires with pliers and I got a very small shock if I touched the wires with my fingers. By being extra careful, I was able to connect all the white wires with a wire nut and get everything back together properly. Everything seems to work ok. FYI, my panel box is Federal Pacific. My question is why am I getting the tiny sparks and small shocks when the 15 amp breaker is off and when the main breaker is turned off? Any suggestions are greatly appreciated.
Thank you.

 

[The Deez]

sell asap

hmm, this is a good one, bonding issue somewhere maybe, how close is your neighbor?

 

[sjh]

Don't understand "bonding issue". Nearest neighbors are probably 100' away. I've been reading some bad things about Federal Pacific panel boxes. Could it have something to do with bad breakers somehow letting through a little current?

 

[The Deez]

yeah fpe are called "no blows" in the field, they were just bad at tripping when they were suppose too. if you have a volt meter you can shut the main off then test the load side of the main breaker, their is a lot of things that could be wrong with that scenario. this isn't a DIYer issue you should call somebody in to have this looked at

 

[sjh]

Calling in an expert seems like a good suggestion and something I will do. I just like to understand what's going on so I can talk intelligently about it to the pro. I will do some volt meter checks but don't plan on venturing too far inside the panel box though. Thanks.

 

[mpoulton]

With the main breaker off, are all electrical devices in the house dead? If not, then you have some circuits somehow bypassing the main breaker (lots of ways this could happen in an older system) or the main breaker is not opening properly. If the whole house is dead but you still have current on those neutrals, it is probably coming form a neighbor's house and probably indicates that either you or a neighbor has a loose or open neutral. That is a potentially very serious problem, and requires the power company to come investigate ASAP.

 

[sjh]

Thanks very much Deez and Mpoulton. You've definitely convinced me this is not a problem for my limited electrical knowledge. I'm calling an electrician this morning to come investigate.

 

[sjh]

Did some more checking this morning with my meter. Today, the main is shutting off everything in the house just fine. Not sure why I had problem yesterday - maybe operator error for not getting it fully off or maybe it was my imagination there were tiny sparks when I touched the white wires with my pliers (I had been shocked with just the line breaker off) or maybe the main just hadn't been turned on/off in such a long time that it needed to be switched a couple times to make it work right again. Don't know but will be getting it checked further by electrician.

This morning, I looked more carefully at the wires and traced where they went. The wire running directly from the panel box to the light box is 14/3 with the black wire hooked to one circuit breaker that controls the basement lights and the red wire hooked to another circuit breaker that controls the furnace. I got shocked because I only turned off the circuit for the lights but didn't realize the furnace circuit was being carried by the same wire and going through the same box. My mistake and from now on I will turn off the main before doing any electrical work in that house.

Is it appropriate to use the same 14/3 wire for 2 separate circuits?

 

[SD515]

You have a multi-wire branch circuit. The red wire to the furnace was still using the white neutral when you took the joint apart, and is what caused the sparks you saw. Yes, you can use 14/3 for 2 circuits, but now it's required to use a 2-pole breaker for them at the panel, to avoid what happened to you getting shocked.

 

[The Deez]

yeah and open neutral can also cause problems with your electronics