Ok, I got some help yesterday with confirming a wiring diagram which I implemented today. but I ran into a new problem which is really puzzling me as well as worrying me.

I was going to add the circuit I put together to an existing 15 amp circuit which I connected to through an outlet/junction box. in this JB were two fabric wrapped 14/2 wires pig-tailed to the outlet, so 3 black wires wire nutted and 3 white wires wire nutted then the braided ground grounded to the box. This outlet powers my TV so I tripped the breaker, the tv and lights in the area all went out. and I got to work. I removed the old JB and outlet and replaced it with a new JB and new outlet and added my new circuit, starting with the black wire, so now I have 4 black wires wire nutted together (the 2 original wires, the pigtail to the new outlet and the new circuit) I started to connect the white wires and when put all four together they sparked! I thought that very odd so by process of elimination I determined that when I touch one of the original wires to my new circuit, that is when it sparked. I removed my new circuit went back to the original configuration with just a new outlet and when I tried to plug my tv back in the outlet worked, but crackled a little inside. I unplugged the tv and shut the breaker and will be calling an electrician in the morning, but I would like to know... how is it that wire sparked when the breaker was off? Also, I cannot trace the wires any further than I can see as they go into the cinderblock foundation.

Thanks,
Ken

 

You may be dealing with a multiwire branch circuit that is sharing the neutral between two hots. There sounds like a load is on the other hot leg. When you connected the neutrals the current completed the path bath to the panel.

 

White wires should never be grounded to the box.

You may have two circuits accidentally connected together.

 

Sounds reasonable, but how will that affect my adding a new circuit to that run... and how would the wiring work? I can't attach the neutral to the circuit without it sparking....

 

Sorry, let me clarify, the white wires were wire nutted and the two wire sets where grounded to the box by their braided ground wire

 

Just for clarification, you are not adding a new circuit. You are extending an existing circuit. A new circuit is added by installing a new breaker in the distribution panel and wiring from that to new loads.

That said, if your existing system is a two-wire system, without an EGC (a ground wire), it should not be extended unless you add an EGC to it. A new circuit with a ground wire should be run instead.

You almost certainly have run into one side of a multiwire branch circuit. The breaker controlling the other side should be immediately above or below the one you turned off to start working on this.

 

Thanks guys for the help with this, I had an electrician come in and it turns out the issue was the switch that I was wiring in is controlling old fluorescent light fixtures and there was a short in one that allowed the power to return and spark after the hot leads where attached and I tried to attached the neutrals. on top of that the circuit breaker that I turned off which controlled the outlet I was extending from was, according to the electrician," in phase " with another circuit so when I turned off the circuit, the power went out so the tv was off, but there was still power through the line, I actually had to shut down a completely different circuit to kill the power to that outlet. I am happy I called the electrician before I went any further.

Thanks for the insight and help guys, I'm very appreciative!