On Wednesday, August 12, 2015 at 9:19:05 AM UTC-5, wrote:
On Wed, 12 Aug 2015 06:27:03 -0500, philo wrote:

On 08/12/2015 02:47 AM, Uncle Monster wrote:


From your description of what you were cutting out, it appears to be ridged conduit. I can imagine that it's a fun job. If you think about the why of rigid conduit, pretend you were converting a home from gas lighting to electrical lighting back in the day, where would you install the wiring if not knob and tube? If I already had a pipe somewhere that was no longer being used for gas, I think I'd use it as a conduit for wire. Of course wiring practices evolved and changed as standards were published and inspections became the norm. I'd guess there were many house fires cause by the ignorance of that magical source of energy, electricity. That's probably the reason the rules and standards for electrical wiring were codified by the National Fire Protection Association which may have come into being for that reason. I don't know the history of the NFPA without reading about it because it may have been around since the days of gas lighting and the need for standards back then for
insta
lling gas lines in buildings. Since I haven really researched it, I'm just guessing. Now that I've become curious, I must vanish for a while and read up on the history of the organization, dammit! ?(????)?

[8~{} Uncle Code Monster




The conduit was not an old gas line. It would have been all new at the
time and of greater diameter that the pipe used for gas lighting.

It would have been essentially impossible to pull wires through that
thin diameter pipe.


Though they were capped off of course, the gas lighting pipes were still
connected when I moved into my house and one of the first things I did
was to disconnect them.

Fortunately there was a junction in the basement so I could disconnect
them all at once.


Another thing I did almost immediately after I moved in here was to take
the light switch out of the shower stall!!!!!


You are not getting wires through elbows either.

They did convert gas light fixtures to electric tho and that is
probably why fixtures use NPT size threads today. They are running
threads instead of taper but it is still NPT even when they come from
offshore.

I considered 90 degree gas/water elbows and I'm sure someone figured that out too back then but imagine if you had a 3/4" pipe from basement to the upper floor that was no longer going to be used for gas lighting and you needed to get power up there. I'd take the elbows and valves off that pipe and run the wires through that. Friction tape could be used to protect the wire where it entered the pipe since insulating or cast metal bushings hadn't been invented yet. I'm sure plastic electrical tape was a dream at the time. A smart fellow figured out how to make conduit elbows in those days as electrical power wiring evolved. I've made my own elbows out of rigid conduit for many years. I'm out of practice now but I was able to eliminate a lot of separate elbows and couplings on big jobs because I could put a 90 degree bend in the middle of a stick of 4" rigid conduit and make it fit exactly without using nipples and couplings to make up for poor measurements. A lot of guys slapped their conduit runs in willy-nilly and they looked like hell. I made my own bends because if I had stiff cable to install, I could make a wide radius elbow which would make pulling the cable into the pipe so much easier. Elimination of as many couplings as possible made pulling wire a lot easier because there were fewer places for the end of a fish tape or wire bundle to get hung on or stuck especially in the area around an elbow. It would be fun to research the evolution of electrical wiring in the United States starting with Edison's DC power systems for cities and the take over of the power grid by Tesla's AC power standard. Just think, if J.P.Morgan hadn't pulled the rug out from under Tesla, we'd have a technically mature wireless power grid by now. ¯\_(ツ)_/¯

[8~{} Uncle Electric Monster