Hello again, have asked a few questions on here, since I am finishing my basement. Anyhow I have a found a few things that concern me with the existing electrical installation. For example I took the housing off an existing (must be an end of the circut) ceramic light fixture in the basement only to discover that the ground wire was not connected. Today I took the front panel off the breaker panel and notice that many of the wires connected to the breakers had been stripped back so far that the copper conductor was exposed, one look like it was exposed at least 3/4 of an inch. Is this a saftey concern or is the norm? By the way my house is a 3 years old spec house and was built by a large home builder in the area
Thanks
Dan
Replies
Yes.
Re the ceramic light fixture, probably this is in a plastic box, so there's nothing to attach the ground to (unless it's a pull-chain fixture).
3/4" of exposed copper is sloppy, probaby not to code, but not especially unsafe. They are right next to the clamp screw which is also exposed and easier for someone to accidentally touch, and 3/4" isn't enough that two adjacent wires could accidentally come in contact with each other, or enough to allow the wire to touch the enclosure.
The ideal exposure would be about 1/4" -- just enough to make it clear that the insulation hadn't gotten caught in the clamp.
As pointed out porcelain light fixtures, being completely incapable of conducting electricity, seldom have ground connections. In these cases the ground wire is best neatly tucked into the back of the box.
In most cases I strip wires going to breakers about half an inch back. This allows you to see a bit of copper outside the terminal when the wire bottoms out. You have to shine a flashlight down the hole to see it. This prevents exposed copper outside the breaker.
In some panels the neutral or grounds are directly below the breaker connections. Exposed copper here can make checking or tightening neutral connection very much like a higher voltage version of the old 'Operation' game. The buzzer was much more relaxing.
Splitting the insulation while removing the jacket on Romex is much the same problem except it is usually more hidden. I have a couple of screwdrivers with flash marks where I failed to see the problem. Another reason to be careful and wear those safety glasses working a panel.
For those who do not do it for a living I think there is a strip guage on many CB's like there are on other devices.
Exactly right. There is usually some sort of strip gauge. You may need to look very closely. Many are black on black and hard to see, if you can find them, even in a strong light.
Your right most people who do this stuff for a living just guestimate, half inch to five eighths stripped seems to work well for most breakers, and see how any particular length works. A bit of copper snipped off the end or a touch more stripped makes a nice installation.