Secondary Panel Question

[avayan]

Will be adding 220 VAC at my garage's other side. Went to Home Depot and bought 50 feet of 4-3 NM-B cable which I will route from the main box to a sub panel. I was thinking about using EMT conduit (1.5" diameter) to route it across the garage walls. Is this the right conduit to be up to code here in Texas, or should I use something else? Thanks for your input!

 

[pattenp]

If you are using a continuous run of EMT from panel to panel you should use individual wires of THHN, not NM cable. If using the EMT as a protective sleeve for the NM in certain places is okay.

 

[Bert_]

^This

Running NM in conduit is perfectly legal, but a huge pain.

What size breaker are you planning on using to power your sub panel? Any specific loads your powering?

 

[ssdave]

Running NM in conduit is acceptable; however, for 1.5" conduit, your cross sectional area of the NM cable has to be less than 53% of the cross sectional area of the conduit (presuming you're only pulling one cable). If you're pulling 3 separate wires/cables, you can only use 40%. So, measure the cable and check it. A 1 1/2" conduit has cross sectional area of 2.05". Doing the math, the cable has to be less than 1.17" in diameter to meet code if it's the only cable in the conduit. It might be hard to pull through, depending on your bends. NM doesn't pull well. You might have to go to 2" and soap it well to pull, or use an LB or C condulet or a pull box to break the pull into sections.

 

[wyliesdiesels]

4-3nm-b is expensive.

What size breaker you using?

If 90a, #2 al SER wouldve been a lot cheaper.

 

[theoldwizard1]

If using the EMT as a protective sleeve for the NM in certain places is okay.

I have never heard of a situation where NM or UF is NOT allowed inside conduit as long as you are not exceeding the fill limits.

 

[pattenp]

I have never heard of a situation where NM or UF is NOT allowed inside conduit as long as you are not exceeding the fill limits.

I didn't say it was not allowed in certain cases. If running a complete conduit system you don't want to use NM, makes no sense. It makes sense to use conduit to sleeve NM where needed for protection. You took my sentence out of context.

 

[wyliesdiesels]

I have never heard of a situation where NM or UF is NOT allowed inside conduit as long as you are not exceeding the fill limits.

NM is NOT allowed in conduit outdoors.