I don't have time to do any work now...but the coating is cloth covered
I just got back from Home Depot. I was going to buy some ground
clamps...and I ran into the electrician who put in the 200 amp service
and told him what I was up to.
He said it is OK to bond around a bad electrical ground...however the
mechanical connection should still be good...which it is not...
So I am going to to the right thing and replace all...but not today.
BTW: The ground clamps were more expensive than I figured and all total
would cost about the same as Romex and a few junction boxes.
Another intersting tidbit about old copper wiring. Early rubber
insulated wire used real gum rubber - which needed to be vulcanized to
make it hard - and one of the chemicals used to vulcanize rubber is
sulphur - which is very corrosive to copper. The wires were "tinned"
before insulating to protect them from the sulphur.
also interesting is the way wire size is measured. Wire is made by
drawing it through a series of increasingly smaller dies or
draw-plates to create its final size. It is believed that wire gauge
numbers were originally based on the number of dies that the wire was
drawn through. For example, No. 1 was the original rod, and if it was
drawn through 12 dies it became 12-gauge wire. If two more dies were
added, it became 14-gauge wire, etc. Thus, the larger the gauge
number, the larger number of dies it was drawn through, and the
smaller the wire. This was the original Brown & Sharpe standard that
morphed, more or less, into the American Wire Guage standard used
On Wed, 06 Aug 2014 22:49:03 -0400, email@example.com wrote:
Raceway systems are still supposed to be bonded (to ground) but if you
have a grounding wire, bonding the raceway is less critical because
you are not using it as the fault path to equipment.
You still do not want a "hot" raceway.
On 08/06/2014 10:49 PM, firstname.lastname@example.org wrote:
If I cannot get this fixed by using clamps and bonding around the
hi-resistance areas...and now it seems there are four of them...
I am just going to Romex everything. The conduit in the basement is
perhaps 25 feet long and from there, a short run of BX goes up to a
three outlets at various places along the run.
On 08/07/2014 07:12 AM, email@example.com wrote:
I am heading off to get some ground clamps now and will try to get all
grounds down to less than an ohm.
If that does not fix it, I will have to replace the run.
The boxes have rusted screws and I'd have to chisel them off and re-tap
the holes. All the BX feeds have poor grounds too. If I have to replace
the BX and the junction boxes, it's going to be easier and better to
This house only has three original rigid conduit runs and the other two
are perfectly OK, so I'm going to leave them alone.
When I bought the house in 1979 it had 30 amp, 115 service.
In 1932 that must have been pretty nice!
Just to clarify, code does not allow Romex to be run inside conduit, except
for short runs for physical protection.
However, it would be a fairly trivial matter to pull out the old wiring and
run new THHN wire in the old conduit. You could use the old wires to pull
the new wire through.
Of course, if the conduit and boxes are exposed, I would probably take out
the old work and run new boxes and cable. By the time you fiddle with
stripped conduit and corroded terminals, you could have all new work
That's not _exactly_ right. The tables in the back of the NEC have all
the conduit fill info and include how to calculate the area of an
elliptical cable and also how to treat a multi-conductor cable as a
single conductor for fill calculations and as well as the temperature
derating info for the conduit.
The "prohibition" is for NM in conduit without the additional derating
for the conduit required, but that isn't blanket exclusion entirely.
That said, the difficulties in pulling NM instead of single THHN runs
makes it such that one would choose the latter in almost all cases, anyway.
If it is pre-rural electrification all bets are off and it COULD be
iron core wire. If it was wired for 48 volts DC there was no enforced
code at the time.
There has never been an "approved" branch circuit conductor made of
iron in Canada or the USA. It is used extensively in power
distribution, and in copper clad form, in RF distribution where skin
effect makes copper clad wire just as good as solid copper - with
higher tensile strength and lower cost. It has also been used for
telephone distribution cable.
On 08/07/2014 11:39 AM, firstname.lastname@example.org wrote:
The original locations were DC, yes, but I'm not sure of all of what
might have been available options in the early 30s when the farrowing
house was built/wired. It did predate REA reaching us by quite a long
period, though, as that didn't happen until '48 (folks began collecting
petition/formation signatures in early '45 before V-J day and the co-op
was formed very shortly after the end of the war but it took almost 3
years to reach us with the lines towards the west end of their service
area and Dad was on board from its originizational meeting for 50 yr).
Well, while that may well be true, that philo has what seems to be the
same material as here shows it wasn't at least unheard of for there to
be something other than Cu in the time frame that seems to coincide with
that of this here.
I asked at the coffee shop this morning if any of the other old codgers
had any recollection -- one fella' suggested the core might be
nickel-silver (or "german silver")...would meet the indications of the
observed visual characteristics. I'll have to do some more serious
digging around and see if can't find a spare chunk to do actual
'spearmints with which...
While the main house and barn, etc., were wired and ran on the Delco,
grandfather was thinking ahead and the wiring was done with eventual
power in mind. All that needed changeout when connected to REA was the
DC switches (of which I still have a half-bushel basket full of the
push-button Victorian-era mother-of-pearl buttons for those who are in
dire need of same. :) )
Was interesting when still doing coal analyzer support for Sask Power
there're still enough farmsteads there that there was a co-op store in
Weyburn with DC appliances on their showroom floor (as recently as about
And, just to clarify we're not totally still in the dark ages, the folks
essentially gutted the house in the late '70s before moving from our
"little house" next door. All new plumbing/wiring/insulation
added/etc./etc./etc., ... then.
Most all the main outbuildings were drastically upgraded in the 60s
after Dad took over the operation from grandfather and we added quite a
lot more ground and larger cattle operations to get with the changing
times and particularly after the 50s drought broke there were some good
years that allowed for some investment. So, other than just these few
locations like the aforementioned garages, the old shop, the farrowing
house (now totally unused except for storage), etc., that have nothing
more than lighting circuits for a few overhead bulbs and (maybe) an
outlet or two, it's all pretty much up to what was Code at that
time...I've never worried about much of the newer Code changes as never
could see any real need as was discussed in an earlier thread.
On Thu, 7 Aug 2014 14:04:57 +0000 (UTC), HerHusband
That is a common misconception but not true.
The biggest problem with Romex in conduit is "fill:"
You have to compute it as a conductor the size of the widest
It is also pretty hard to pull. (no nylon jacket like THHN)
I think Philo was talking about abandoning the conduit altogether tho.
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