SO cord in conduit

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Mgab94

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So, my buddy is wanting to install an RV plug on his property about 150' away and needs help. I told him the proper size wire and conduit size he'll need. There is already 1 1/2" conduit part of the way there so he's gonna use that which is fine. But then after I told him what he needs, he goes and buys a 200' 6/3 SO cord because it's way cheaper than THHN. I told him I won't help pull it in and it's against code and exceeds conduit fill. I'm correct in assuming the it will be extremely difficult to pull that in, right?
 
Yes I would not do that besides the fact that it is not compliant. I find it hard to believe that rubber cord is cheaper than thhn or more correctly thwn-2 wire.

Also I don't believe the lugs on the breaker is listed for the stranded wire in an SO cord. So is not even rated for wet location.
 
It is not code compliant but probably not especially unsafe. If he decides to go ahead with this plan, maybe it is best if you stay out of it.
 
Dennis Alwon said:
Yes I would not do that besides the fact that it is not compliant. I find it hard to believe that rubber cord is cheaper than thhn or more correctly thwn-2 wire.

Also I don't believe the lugs on the breaker is listed for the stranded wire in an SO cord. So is not even rated for wet location.
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6/3 SO cord can be gotten for about $3.50 a foot pretty easily.

#6 THHN is about $1/foot. You would need three of them plus a ground so I can believe it is cheaper to get the cord.
 
petersonra said:
6/3 SO cord can be gotten for about $3.50 a foot pretty easily.

#6 THHN is about $1/foot. You would need three of them plus a ground so I can believe it is cheaper to get the cord.
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At my local HD, 6/3 SOOW is $4.73, but there's no ground. For comparison, 6/4 is $6.14 per foot. It doesn't appear they sell straight SO. For THHN, you'll pay $0.69 per foot, any color. If you already have the conduit, advantage THHN. For 1-1/2" EMT, it's $31.47 for a 10' stick.
 
zbang said:
There certainly is a ground, it's the green wire :LOL:.

Remember that type S (and W?) have only insulated conductors and count all of them, unlike NM or other types (e.g. 12/2 NM which includes the ground as bonus).
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OK, very funny. My point was, if you need 4 conductors of THHN, you need 6/4 SOOW. Also, I seem to remember (very long ago, I'm sure) you had to be careful to pick NM with the ground if you wanted it, as it came both with and without. Do I misremember?
 
petersonra said:
6/3 SO cord can be gotten for about $3.50 a foot pretty easily.

#6 THHN is about $1/foot. You would need three of them plus a ground so I can believe it is cheaper to get the cord.
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6/3 in rubber cord means exactly that -- 3 wires. It has a ground, neutral and hot. I also assume the load is 120v but you were thinking 4 wire
 
petersonra said:
6/3 SO cord can be gotten for about $3.50 a foot pretty easily.

#6 THHN is about $1/foot. You would need three of them plus a ground so I can believe it is cheaper to get the cord.
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SO cord has a ground! It's the green wire. This cord can only supply 120 V properly. So, 3 #6 single conductors is the comparison.
 
gadfly56 said:
... Do I misremember?
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I think you remember just fine. I've seen NM cable with a bare wire, without, and with a reduced-size ground.
I never needed to be careful while shopping for it because I grew up in Chicago and never encountered NM cable until full-size ground was the only variety available.

Dennis Alwon said:
6/3 in rubber cord means exactly that -- 3 wires. ...
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And, of course, 6/3 in NM now means 4 wires, in compliance with the Universal & Eternal Principle of Maximum Confusion.
 
Pulling rubber wire through conduit is no pleasure! Lots of lube and words. The rubber sticks to everything !:eek:

Remember the whole phrase for "Romex" is NMWG-B, meaning it has the ground wire, but it is not counted in the conductor number. Nobody writes it that way now, since it has all had ground wires for the last 50 years.
 
gadfly56 said:
OK, very funny. My point was, if you need 4 conductors of THHN, you need 6/4 SOOW. Also, I seem to remember (very long ago, I'm sure) you had to be careful to pick NM with the ground if you wanted it, as it came both with and without. Do I misremember?
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Started going electrical work in 1967. At the 2 supply houses that I used all of the romex ( NM cable ) had a ground conductor. Only option was they charged between think it was 50 cents to a dollar more for the plastic jacket romex verses the what we called woven jacket. The cheaper woven jacket was horribly pulling thru a lot of joists. The black tar like matetial would coat your hands especially in warm weather. My parents house was built around 1952 and the 14/2 romex all had a #16 guage vround wire in it. Houses built a year latter across the street from them had no ground wire inside of romex.
 
garbo said:
Started going electrical work in 1967. At the 2 supply houses that I used all of the romex ( NM cable ) had a ground conductor. Only option was they charged between think it was 50 cents to a dollar more for the plastic jacket romex verses the what we called woven jacket. The cheaper woven jacket was horribly pulling thru a lot of joists. The black tar like matetial would coat your hands especially in warm weather. My parents house was built around 1952 and the 14/2 romex all had a #16 guage vround wire in it. Houses built a year latter across the street from them had no ground wire inside of romex.
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My parents house was built around 1960 (NJ) and had that silvery woven cover on the cable. No ground wire.
 
gadfly56 said:
My parents house was built around 1960 (NJ) and had that silvery woven cover on the cable. No ground wire.
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I started working in the electrical department of a hardware store in 1990, and then wiring in 1992.

The Romex without a ground was called "plain"

By the time I started wiring, we were pretty much using it just for switch loops, 3-way travelers, and things such as that
 
What I have seen happen with wire prices is that some stuff, like big SO cord, can sit on the shelf for a long time and stores price it based on its incoming cost. So wire that moves through inventory more often, like THHN, ends up reflecting the current madness in wire pricing, whereas that SO cord price was likely based on 2019 costs.
 
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