On Saturday, October 11, 2014 2:21:45 PM UTC-4, N8N wrote:
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pe. Article 250.130(C)(1) states that is is permitted "At any accessible p
oint on the grounding electrode system as described in 250.50". The waterp
ipe is part of the grounding electrode system. The water meter and water h
eater bonding jumpers would have to be in place and the clamp would need to
be approved for the type of metal piping.
e ground clamp (Brass) attached to a steel pipe acted as a battery. Just l
ike a water heater. The clamp should not have been buried in a finished ce
iling. The ground wire should have been run over to the water meter locati
on where it would have been accessible and could have been clamped to the w
ater pipe or the grounding electrode conductor.
unding electrode system, only something that needs to be bonded *to* the gr
ounding electrode system, so relying on a metal pipe for a ground for a pre
viously ungrounded receptacle is no longer allowed, as others have already
stated.
*Go back to your code book Nate and read the sections that I posted.
On Sat, 11 Oct 2014 10:00:19 -0400, "Robert Green"
Back in the olden days a cold water pipe was going to be the best
electrode around. Plastic plumbing was unknown and houses only used
sweated copper or threaded galvanized, all the way to the water plant
or the well casing. People could have an open neutral and never even
know it
On Sat, 11 Oct 2014 10:00:19 -0400, "Robert Green"
My bet is the ceiling was installed LONG before home inspectors became
in vogue.
Ant it was likely done long before plastic pipe was an approved
option.
Except the upgrade was likely done either during or before the
seventies. - so not ENTIRELY a moot point. It was "standard practice"
and "approved" when it was done.
Not to say it should not be redone today.
By code NO electrical connection is allowed to be "concealed". Ground
or otherwise, they must be "accessible" - and above a stapled ceiling
does not comply.
On Saturday, October 11, 2014 3:15:51 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:
To be fair, if accessable, you could make a good argument for replacing that as well, because any ungrounded non-metallic cable likely does not have a 90C temperature rating as does currently produced NM-B.
If I saw any K&T I'd be tempted to draw up a plan for eventual complete replacement ASAP however... even if it was done perfectly when installed simple age makes one worry about the integrity of the insulation... nothing lasts forever.
nate
On Saturday, October 11, 2014 3:15:51 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:
Copy and paste of first post...
This question was posted in another forum by someone that I know and I
thought that I would try posting it here to get some feedback on his behalf:
He wrote,
"In a house that has ungrounded, 2 prong outlets, with wiring in good
condition, is it acceptable (and allowed by current electrical code) to run
a separate ground wire from the outlets back to the ground at the panel, in
order to be able to replace the 2 prong outlets with 3 prong outlets?
Existing wiring is in very good shape."
Thanks
NOTE: around here the most common ungrounded outletsare because of K&T
Are you saying you would draw up your plan ASAP for eventual replacement?
Why the hurry for plans for eventual replacement? Why not eventually come
up with plans for the thereafter ASAP replacement? Or ASAP plans and ASAP
replacement? Or . . .
On Sat, 11 Oct 2014 11:46:23 -0700 (PDT), John G
250.52(A)(1) says
Interior metal water piping located more than 1.52 m (5 ft) from the
point of entrance to the building shall not be used as a part of the
grounding electrode system or as a conductor to interconnect
electrodes that are part of the grounding electrode system.
<*Actually the 2014 code does still permit the connection to the waterpipe.
Article 250.130(C)(1) states that is is permitted "At any accessible point
on the grounding electrode system as described in 250.50". The waterpipe is
part of the grounding electrode system. The water meter and water heater
bonding jumpers would have to be in place and the clamp would need to be
approved for the type of metal piping. >
I really don't want to dive into this can of worms again so I'll just note
all the potential failure points of using a clamping method from the code
fragment you cited and I'll bet many more live in 250.50:
IF and only if
1) The water meter is jumpered
2) the water heater is jumpered
3) any section of the pipe that's been replaced by pex or plastic is
jumpered
4) the right kind of clamp is used that won't cause galvanic corrosion
I would add that the wire from the outlet box is labeled as to where it's
going off to. When I checked the outlet and it failed, opening the box was
no help. When I tried to trace the cable back to the panel with a fox and
hound I couldn't tell where the ground wire was going because it was stapled
high inside the joist (badly stapled, I might add).
I removed one stapled ceiling tile (what a mess that was - so much so it
helped lead to taking the whole damn ceiling down) and saw the wire going
off at 90 degrees from the main cable. Tracing that proved to be impossible
with the fox and hound so that aided in the decision to pull more tiles
(this was a critical outlet for power tools in the workshop). The readings
on the tester were flakey. Sometimes it would be grounded, other times the
test lamp would flicker or extinguish completely, especially if there was a
load on the second outlet of the receptable in question.
It's just my opinion, obviously, but a wire that's used primarily as a
life-saving measure going off to parts unknown should have a "good"
provenance. It was obviously NOT done by an electrician because of how
poorly the wiring was connected - it was nicked and barely under the screw
and not stapled near the box. Another clue was that it was 10 feet FROM the
damn panel and done when the ceiling wasn't in place so a real sparky would
have just run a new wire and breaker (and they did for the window air
conditioner outlet that was clearly added on at some point).
Tote all the potential failure points up and it's clear using a pipe as a
ground has lots of potential risk - at least compared to pulling new wire.
I understand why it was grandfathered: I am sure the NEC weenies feel that
any form of grounding is better than no grounding at all.
Many of the outlets in the house were three-pronged but NOT grounded, FWIW,
another sign of a rank amateur. Still with the basement open it would have
been simple to do it right and after pulling the ceiling that's what I did.
Replaced all the old outlets that I found that had three prongs but no
actuall ground connection with new two pronged ones and ran all new circuits
to areas that were critical - along with GFCI's.
This was 1940's cloth covered wiring and I am sure oxidation of the
conductor along has slightly degraded its ampacity.
<That is what I think happened in your case. The disimilar metals of the
ground clamp (Brass) attached to a steel pipe acted as a battery.>
FWIW, it was a plated steel clamp on a copper pipe - same thing really.
<Just like a water heater. The clamp should not have been buried in a
finished ceiling. The ground wire should have been run over to the water
meter location where it would have been accessible and could have been
clamped to the water pipe or the grounding electrode conductor.>
I think you're 100% correct about how that happened. Obviously none of this
work was ever inspected - properly at least - and the only good thing about
all this jack-legging was I got to knock a few thousand off my offer after
doing a walkthrough of the house with my outlet tester. I recall the
comment "We had a lot of appliances that had three prongs so my son replaced
the old two prong outlets so we didn't have to use those adapters anymore."
The sounded proud that he could do it! I really don't think they understood
the ramifications of using 3 prong outlets on ungrounded circuits. Someone
did, eventually, which is why the green wire to the basement outlet
eventually appeared. I believe he had installed new shop lights that needed
a ground to operate properly.
The wiring in this house ran up to the attic and then down again like
octopus tentacles inside hard plaster walls so running a ground wire along
the original cables (or pulling new wire) just wouldn't be feasible. And
that's why I can understand the NEC rules about waterpipe clamps.
So I ran new 12/2 w/ground and GFCI's to the window AC's, the outside of the
house, the kitchen and the office and used dual skinny breakers to wire them
to the panel. For the most part, only very light loads are now running off
the old wiring. Much of it is CFL lighting, further reducing the risk of
overloading the old wires and in most cases, not needing a ground wire
anyway.
At first I was concerned that I had too many dual breakers, but the electric
consumption has dropped slightly each year as I retired plasma TV's for LED
TVs, 30 year old refrigerators for new high eff. ones, CFLs for tungsten
lighting, etc. So it's clear that even though I have more circuits than
before, the total load on the panel is actually lower than it's been
historically.
I'll save it for another thread but my neighbor's electrician son solved a
very interesting puzzle in which some of the lights in his mom's house went
off for several hours early in the AM and then came back on by themselves
without resetting any breakers or GFCI's. I couldn't diagnose it, and
neither could he until I told him that a single UPS's started chirping at
3AM, which I thought was low voltage but seemed to be battery failure., so I
got up and shut it off. No other UPSs beeped so I assumed it was a local
event until my neighbor told me about her basement tenant's lights going
out, too. When I restored power to the UPS and turned it back on the next
day, everything was fine and the battery tested out as good - I was about to
replace it just in case but it was less than a year old.
You've got good analytical skills, John. What do you think it was? (-:
*I don't have a simple answer for this. Things that I have found when trou
bleshooting that particular problem are:
Loose connection on the circuit breaker.
Loose neutral connection on the neutral terminal bar in the circuit breaker
panel.
A bad circuit breaker.
Loose connections on one or more electrical outlets on the circuit.
A loose splice under a wire connector (This is common with DIYers who don't
twist wires together before twisting the connector on).
Loose connection on the main circuit breaker or the main feed lugs.
A corroded neutral wire that had a few strands broken as a result of long t
erm water damage. (Water getting into the SE cable and traveling down into
the meter socket and eventually the main panel).
Loose connections in the meter socket.
Loose connections at the weatherhead.
Loose connections at the power company transformer.
A damaged overhead service wire that has been rubbing against the house or
trees whenever the wind blows.
A damaged underground sevice feeder between the meter and transformer.
This past week I got a call from a couple living in a condo who have been h
aving problems with their cable box going out briefly and then coming back
on. I was there a year ago for the same problem on one of their cable boxe
s. This time it was all three boxes. They had the cable compnay come out
so many times to rewire and replace that they will no longer come out for t
his problem which they believe is with the electrical wiring. Last year I
pigtailed and replaced 2 outlets and never heard back from the couple until
this week. Last year they reported that nothing else was occurring such as
flickering lights. This year it was the same, no flickering lights, but t
hey also admitted that they did not use the lights on these circuits too of
ten. I found the three cable boxes to be on two circuits. I checked the v
oltage at the main panel and it was consistent on both phases and to ground
as well as to neutral. I replaced the two breakers and opened up every swi
tch and outlet on these circuits. The outlets were a builders cheapo model
with no screw terminals, only the back stab holes. Every outlet that I re
moved from the wall had the wires come out of the back stab with little eff
ort. On one particular wall receptacle with six wires attached, one of the
neutral wires had only about a quarter inch of copper showing which made me
think that it was not making good contact when it was inserted into the ba
ck of the original outlet. I pigtailed and replaced every outlet on the two
circuits. I tightened every connection in the main panel. The only thing
that I could not do was check the main breaker because it was in a 6 gang
meter stack that the power company had locked up. I told the couple to cal
l me if the problem persisted and I would get the power company to unlock t
he meters.
A tool that I have found to be very helpful is the Amprobe Inspector: http:
//www.amazon.com/gp/product/B005E0XSR8/ref=as_li_tl?ie=UTF8&camp89
&creative“25&creativeASIN°05E0XSR8&linkCode=as2&tag=mrelect-20&
linkId=NH7Y2DQQOIYSDVF7
On the above job it told me that I was on the right track by pigtailing whe
n I compared the before and after readings.
Another tool to use is an ammeter to measure the current on the grounding e
lectrode conductor at the water pipe and the ground rod. If there is curre
nt flowing on the grounding electrode conductor, that tells you that there
is a problem with the neutral conductor.
I should add that I was quite familar with the condo complex above as I hav
e been doing work for the association for several years. In that time I ha
ve found many problems that go back to the original installer. One that st
ands out is a woman who had a new furnace installed in her condo. She kept
having problems with it and the service technician and her own electrician
told her it was an electrical service problem which was the responsibility
of the association. I measured 30 volts between ground and neutral at her
main panel. I go outside to have a look at the meter stack and noticed a
house panel for the outside lights. I took the cover off of the house pane
l and saw a black wire on one main lug, a white wire on the other main lug
and a bare wire on the neutral bar. The house panel only had one circuit br
eaker in it. I removed the stack cover and saw the black and white on the
main breaker and the bare on the ground terminal. I took the white wire of
f the breaker and put it on the neutral bar. In the house panel I took the
white wire off the main lug and put it on the neutral bar. I installed a
separate ground bar and attached the bare wire to that as well as the groun
ding conductor for the one circuit. The woman's furnace is now working pro
perly.
John Grabowski
http://www.MrElectrician.TV
transformer failure where only oner side of the power failed.
that happended here and left me wondering for a couple hours. when I finally figured it out the power company replaced the neighborhood transormer
On Sunday, October 12, 2014 1:05:27 PM UTC-4, bob haller wrote:
d a
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at
so I
al
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ext
ut to
:
lly figured it out the power company replaced the neighborhood transormer
My guess too... can be verified easily if you have a 240VAC receptacle anyw
here to probe (in garage for welder, or laundry room for clothes dryer) one
leg will still be hot but the other will be dead if he is correct. Or jus
t take cover off breaker panel and measure two breakers adjacent to each ot
her, they should be on opposite legs.
nate
I assume that's because once you start moving further and further away from
to POE the more likely bad things are to happen as in unbridged plastic
sections of pipe used as repairs to copper pipe. Makes sense to me!
Thanks for the clarification. I suspect that eventually they'll even
change that requirement as more and more plastic pipe is used inside and
outside of the house. Maybe it's a bias of years of looking at "spaghetti
code" programming with "go tos" and no "come froms" that makes me allergic
to wires not going to a central location. (-:
>Loose connections at the power company transformer.
Bingo. When we compared what circuits had failed it was clear they were all
on one phase. A neighbor who's on the "critical service" program called
them when his CPAP (breathing device for sleep apnea) failed and they sent
out a truck ASAP.
See, I told you that you had good troubleshooting skills. (-:
<This past week I got a call from a couple living in a condo who have been
having problems with their cable box going out briefly and then coming back
on. I was there a year ago for the same problem on one of their cable
boxes. This time it was all three boxes. They had the cable company come
out so many times to rewire and replace that they will no longer come out
for this problem which they believe is with the electrical wiring. Last
year I pigtailed and replaced 2 outlets and never heard back from the couple
until this week. Last year they reported that nothing else was occurring
such as flickering lights. This year it was the same, no flickering lights,
but they also admitted that they did not use the lights on these circuits
too often. I found the three cable boxes to be on two circuits. I checked
the voltage at the main panel and it was consistent on both phases and to
ground as well as to neutral. I replaced the two breakers and opened up
every switch and outlet on these circuits. The outlets were a builders
cheapo model with no screw terminals, only the back stab holes. Every
outlet that I removed from the wall had the wires come out of the back stab
with little effort. On one particular wall receptacle with six wires
attached, one of the neutral wires had only about a quarter inch of copper
showing which made me think that it was not making good contact when it was
inserted into the back of the original outlet. I pigtailed and replaced
every outlet on the two circuits. I tightened every connection in the main
panel. The only thing that I could not do was check the main breaker
because it was in a 6 gang meter stack that the power company had locked up.
I told the couple to call me if the problem persisted and I would get the
power company to unlock the meters.>
They call them "backstabs" because IMHO, that's exactly what they'll do to
you. I became a hero to my wife (when we were still dating many moons ago)
by fixing a garbage disposal that was about to be replaced after her dad,
her handyman friend and even an electrician could not diagnose the problem.
A faulty back stab on the control switch (which was on an outside wall where
it got cold enough for thermal contraction to make it loose) turned out to
be the culprit. The clue was it happened more in the winter than in the
summer. The switch's backstab clips still gripped the wire - a little - but
they were very easily pulled out of the holes, which doesn't happen in a
good (if there is such a thing) backstab connection - at least not when they
are new. Just moving the wires out of the backstab holes and under the
screw fixed it. I did spend a lot of time upside under the sink before
deciding the problem lay elsewhere. (-:
<A tool that I have found to be very helpful is the Amprobe Inspector:
(Amazon.com product link shortened)89&creative“25&creativeASIN°05E0XSR8&linkCode=as2&tag=mrelect-20&linkId=NH7Y2DQQOIYSDVF7
On the above job it told me that I was on the right track by pigtailing when
I compared the before and after readings.>
I recall seriously considering this tool before when I had a near fire from
a space heater plug that had become partially pulled out of the outlet. I
recall that it didn't detect arc faults and so I passed. Is that correct?
I seem to recall not many testers can detect potential arc fault situations
until they actually start arcing, but my memory isn't what it used to be.
It would be very useful, it sounds, in detecting old wires that have lost
some of their current carrying capability over time.
I was pretty sure I had that problem with old, cloth covered wiring that had
always had an oxide skin whenever I stripped it, but instead of trying to
test them, I just ran new outlets and took all the loads over 5A off the old
outlets. Doesn't mean someone won't plug in a space heater in one of those
old circuits some day so it might be worth almost $300 to know in advance if
that's going to be a threat. As I recall, a load like that might not trip
the breaker but could cause old wire with reduced capacity to start a fire
in the walls.
<Another tool to use is an ammeter to measure the current on the grounding
electrode conductor at the water pipe and the ground rod. If there is
current flowing on the grounding electrode conductor, that tells you that
there is a problem with the neutral conductor.>
This weekend I went to reach for my auto-ranging Wavetek A20 tong meter and
discovered the alkaline button batteries had leaked so much they destroyed
the damn thing. We can put a man on the moon, but are still plagued by
leaky alkaline technology. I the future I will make sure I use either
silver oxide or lithium button batteries if they are available in the size I
need. Really cheesed me off - it was a great meter with tongs just the
right size to fit into my circuit breaker panel.
It was invaluable in redistributing the loads in the panel and helped
uncover a 20A kitchen breaker that was happily allowing 23A to pass without
tripping. Gonna try a Harbor Freight cheapy (God help me!) just because I
rarely use it now. What really peeves me is that the batteries that leaked
(two LR-43's) were NOT cheap cells - they were Maxell's.
<I should add that I was quite familiar with the condo complex above as I
have been doing work for the association for several years. In that time I
have found many problems that go back to the original installer.>
I don't doubt that. The house my then future wife lived in had plenty of
"cheapest you can find builder specials" in it from the outlets to the
appliances. Guaranteed to last just long enough for the builder to pull up
stakes and move on.
< One that stands out is a woman who had a new furnace installed in her
condo. She kept having problems with it and the service technician and her
own electrician told her it was an electrical service problem which was the
responsibility of the association. I measured 30 volts between ground and
neutral at her main panel. I go outside to have a look at the meter stack
and noticed a house panel for the outside lights. I took the cover off of
the house panel and saw a black wire on one main lug, a white wire on the
other main lug and a bare wire on the neutral bar. The house panel only had
one circuit breaker in it. I removed the stack cover and saw the black and
white on the main breaker and the bare on the ground terminal. I took the
white wire off the breaker and put it on the neutral bar. In the house
panel I took the white wire off the main lug and put it on the neutral bar.
I installed a separate ground bar and attached the bare wire to that as well
as the grounding conductor for the one circuit. The woman's furnace is now
working properly.>
Well, I was right about you having not just good but excellent problem
solving skills. Before I learned to do my own work, I would have X-10
related problems that needed a licensed electrician. It became obvious to
me that some electricians can run new circuits and install A/Cs, furnaces,
etc. but really didn't have good troubleshooting skills.
My neighbor's son (who I first met when he was six years old and who used to
wash my car and mow my lawn to earn spending money) started as a cable
puller for the local CATV company. His boss soon realized he had much more
potential than that and sent him to school to become an electrician on his
own dime, an investment that's paid back handsomely. When people say that
today's kids are no damn good I just smile and don't even bother telling
them that I know better. His father ran out on the family when he was an
infant but he never used that as an excuse for bad behavior like his sisters
did. Instead he took his father's place and was the man of the house by the
time he was twelve, doing whatever he could to bring money in and to help
his mom around the house.
Very interesting thread, John. I'll have questions about that Amprobe. If
it's helpful to you, it HAS to be useful to a DIY guy like me.
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89&creative“25&creativeASIN°05E0XSR8&linkCode=as2&tag=mrelect-20&linkId=NH7Y2DQQOIYSDVF7
On the above job it told me that I was on the right track by pigtailing when
I compared the before and after readings.>