N8N wrote:
wrote:
Nate Nagel wrote:
zxcvbob wrote:
Nate Nagel wrote:

zxcvbob wrote:

Nate Nagel wrote:

Bob F wrote:

"Nate Nagel" wrote in message
...

All right, I'm feeling mildly dumb and a little sheepish not to
mention
slightly sick here... just bought a house for the first time less
than
a month ago, and knew that it had some minor wiring "issues" but now
that I'm assessing what I have it appears that there are bigger
issues
than previously anticipated. Anyway, here's the deal. House is a
two
story colonial with full basement, built late 1940's.
It appears that throughout the house wherever the wiring was
hidden behind plaster it was run in NM not BX and there is no
grounding,
period.




It's also possible that the wiring could be knob-and-tube in a
house of
that age.

Bob


No, it's definitely some early type of NM, although it may not be
officially designated as such. There's two plastic-insulated
conductors (that must be a pretty early use of same; as far as
automotive stuff goes I believe the transition was made about 1955 -
at least it was for Studebaker; I have a '55 coupe which
(fortunately) has plastic insulation on the wiring) in what appears
to be a tar-impregnated cloth jacket. But no ground.

I really, REALLY don't want to have to rewire two complete circuits,
although at this point it kind of looks like I'm going to have to.
I might even have to involve a *gasp* electrician due to the
magnitude of what this project looks like it's shaping up to be,
which makes my Y-chromosome cower in shame. I suppose I could just
install new non-grounded receptacles ahd that would be technically
correct, although then I'm back where I started, as there's computer
equipment on the second floor, and a UPS theoretically should have a
ground... also would feel better if the stuff in the bathroom were
grounded (although I was thinking of rewiring the bathroom anyway to
meet current code with a dedicated circuit, GFCI, etc. which is
somewhat doable as there's a small chase going down to the basement
behind the bathtub, and an access panel, so it's "just" a matter of
getting a cable from behind the bathtub up into the attic and then
back down to the light switch...)

I suppose it's not acceptable to cheat and ground stuff to the
nearest water pipe...

nate




You can still buy ungrounded receptacles and put things back like
original. Most circuits don't really need a ground, like the
upstairs bedroom convenience outlets.

Where you really need grounds (bathroom, kitchen counters near the
sink, your computer UPS, etc,) you can run a separate green wire back
to the service panel ground (or to the nearest grounding electrode
conductor, if that is easier.) The ground wire does not have to run
with the current-carrying wires if you are updating old work.

You can also install a GFCI breaker and then use 3-wire receptacles,
leaving the ground terminal disconnected. In this case, you
technically need to put a sticker that says "GFCI Protected. No
Equipment Ground." on each of the grounding outlets that has a
floating ground.

You can also protect circuits by wiring them thru the LOAD terminals
of a GFCI receptacle.

The most practical solution will probably end up being a mixture of
these methods. HTH :-)

Bob



that may be doable at least upstairs; is it kosher to run, say, THHN
without conduit or greenfield or would I need some kind of plenum
rated wire? Please excuse the dumb questions; I know a lot about fire
alarm but just enough to be dangerous about plain old electrical
stuff. Since I really like this house (and paid enough for it!) I'd
like to "do it right" whenever possible, and certainly would like to
be able to say with a straight face to any prospective buyers in the
future that everything is up to snuff.

nate



From what I can tell, the electric code is silent about that. I just
run a #12 green THHN / THWN-2 wire inside the wall cavities, staple to
the ceiling joists, etc. I run them as neatly as possible and where
they are unlikely to be physically abused. I ground them at a big
split-bolt connector on the main grounding electrode conductor a couple
of feet from where it goes into the electric panel.

I have an older house, and I'm trying to get one properly grounded
duplex outlet in each room, and I don't worry about the ungrounded
convenience outlets. All the basement, bathroom, and utility room
outlets are grounded and GFCI'ed (except the outlet for the freezers.)
All the kitchen outlets are grounded except for one that I couldn't get
a ground wire to so I installed a GFCI receptacle. (the one that I
couldn't ground just happened to be the outlet close to the sink)

Bob

Thanks to you and to the others who replied. I have a coworker who is a
master electrician as well and he also suggested the separate ground
wire, so I think that that may be the plan of attack for the first
floor. Here's what I'm thinking:

-buy some new circuit breakers. I have four spare spaces in the breaker
panel, but I'm going to see if I can get some half-height breakers just
in case I want to add a 240V circuit in the future.

-split the washer and dryer onto their own circuits. (they are
currently sharing circuits; the washer with the hall lighting and the
dryer with the dishwasher.) Also run a dedicated circuit to the (gas)
stove (currently shared with the hall lighting and clothes washer.)
Should this be 20A or is 15A sufficient? I was thinking 15A would be OK
but if current code recommends 20A that's what I'll do.

-If feasible, provide a new 20A circuit for a single receptacle on the
kitchen counter that's currently shared with the 1st floor lighting ckt.
(the other is already on a 20A circuit, and I've installed a GFCI
receptacle)

-Again, if feasible, provide a new 15A circuit dedicated for the
bathroom. cut box out of wall and replace single gang box with light
switch with double gang box for light switch and GFCI receptacle. Leave
pull string up to attic for future installation of an exhaust fan.

-On the first floor, run a single green 14AWG THHN from breaker panel to
receptacles coming up from below and then dropping back down again,
working my way around the perimeter of the house. One homerun for each
circuit (there are two.) Light switches and light fixtures remain
ungrounded; there seems to be no way to deal with those short of
breaking up some very thick and sturdy-looking plaster.

-On the second floor, either follow the same plan as above, but dropping
down from within the attic, or else find the homerun and ground that
back to the breaker panel using the chase behind the bathtub and then
completely rewire the rest with 14/2 Romex from the attic (should be
possible, although I suspect this house was wired "old style" with
switch legs dropping down from the ceiling light fixtures so I may leave
the light switches ungrounded.)

comments?

I'm starting to think that maybe I can do this (assuming, of course,
that She Who Must Be Obeyed displays an aptitude as a fish tape
operator,) although I'm wondering if I'm approaching the point at which
I need to pull a permit. I certainly don't want to **** off the various
local agencies as I do need to deal with them at work.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

You are on the right track to just add the ground wire where possible,
it is much easier. My wife has, over the years, become extremely adept
at grabbing fishtapes in wall cavities with bent coathangers. WIthout
her help, I would still be doing some projects that have been completed
years ago. I prefer metal boxes with ears that pull out when the
screws at the side of the box are tightened. The plastic boxes with
the tabs that rotate out don't have as much area pushing against the
back of the sheetrock/plaster as the flat tabs on the metal boxes.
Also, the plastic boxes do distort their shape a little while the metal
boxes are more rigid.

H. R. (Bob) Hofmann

Where do you find metal old work boxes? My local "big box" hardware
stores do not have them, although I've seen some of the contractors I
work with using them, I believe they get them from supply houses where
they have accounts.

nate
I haunt non-big-box hardware stores.

Bob Hofmann