Conduit fill in 1960

[jwjrw]

Have the # of RHW conductors allowed in a piece of 1 1/4" EMT changed since the early 1960's? I have a job where 3 #1 RHW conductors are in a piece of existing 1 1/4" EMT.


3 # 1 RHW conductors. .2660 x 3 = .798
1 1/4" EMT 40% fill = .598


Is my math correct?

 

[Dennis Alwon]

Have the # of RHW conductors allowed in a piece of 1 1/4" EMT changed since the early 1960's? I have a job where 3 #1 RHW conductors are in a piece of existing 1 1/4" EMT.


3 # 1 RHW conductors. .2660 x 3 = .798
1 1/4" EMT 40% fill = .598


Is my math correct?

Where did you get .2660 from. I get .1901 for #1 Rhw

I see the discrepancy but not sure yet.

 

[infinity]

For RHW without outer covering the correct conductor dimension is (.1901). What type of RHW do you have? Was RHW without outer covering even made in the 1960's?

 

[480sparky]

Per 1962 NEC:

3-#1 RHW @ 0.2715 in? = 0.8145 in? (from Table 5)

1? Raceway w. 3 conductors = 0.6000 in? (from Table 4)

Failed. :roll:

These numbers are for new work. There were different numbers for existing work.

Rob..... I see no mention of any RHW with or without outer covering.

 

[Dennis Alwon]

I see the problem. The one I stated is without outer covering. So I guess if you have the cloth then you are correct.

 

[Dennis Alwon]

Rob..... I see no mention of any RHW with or without outer covering.

Go to the asterisk at the end of the table

 

[480sparky]

Go to the asterisk at the end of the table

You must have a different 1962 than I do.

 

[Dennis Alwon]

You must have a different 1962 than I do.

I thought he was asking about todays code but I see he is asking if there is a code change. Obviously there is a discrepancy. :grin:

 

[480sparky]

I thought he was asking about todays code but I see he is asking if there is a code change. Obviously there is a discrepancy. :grin:

I was posting from the 1962 since the OP was asking about "early 60's". The with/without outer covering doesn't show up until the '65.

 

[infinity]

I was posting from the 1962 since the OP was asking about "early 60's". The with/without outer covering doesn't show up until the '65.

So if his conductors are without he's good. If not, then there's a violation that has lasted 50 almost years. :roll:

 

[jwjrw]

For RHW without outer covering the correct conductor dimension is (.1901). What type of RHW do you have? Was RHW without outer covering even made in the 1960's?

It appears to be cloth. I could barely make out RHW and #1 on it.

 

[jwjrw]

So if his conductors are without he's good. If not, then there's a violation that has lasted 50 almost years. :roll:

Does without outer covering mean single conductors and not like in a piece of cable?

 

[480sparky]

So if his conductors are without he's good. If not, then there's a violation that has lasted 50 almost years. :roll:

I can see no mention of any RHW with or without outer covering in my 1962. It is mentioned at the bottom of Table 5 that RHH and RHW w/o o.c. are the same as THW in the 1965. But that note does not appear in the '62.

The w-w/o outer covering does not show up in Art. 310 until 1975.

 

[tkb]

Even in the 60's the code was ignored by some.

 

[480sparky]

Even in the 60's the code was ignored by some.

Even in the 60's, some places never enforced any code of any kind. Electrical or otherwise.