Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Is there any issue combining different wire sizes in same conduit? It is same wire type. XHHW. Thanks.
Mixing Wire Sizes
- Thread starter Alwayslearningelec
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You know the answer to this.... Of course you can combine different wire sizes. The equipment grounding conductor is often a different size.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Sorry meant different size PHASE conductor for different circuits
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
different size phase conductors for the SAME CIRCUIT? That would be a no.
PS: As pointed out to me, this may not be a good idea but so long as minimum sizes are covered, it wouldn’t be a code violation.
PS: As pointed out to me, this may not be a good idea but so long as minimum sizes are covered, it wouldn’t be a code violation.
Last edited:
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Are you asking about for example having a 120V 20A circuit and a 240V 30A circuit both run in the same conduit?
You mention specifically xhhw type wire. Are you talking about service or feeder conductors? That could be a totally different answer.
You mention specifically xhhw type wire. Are you talking about service or feeder conductors? That could be a totally different answer.
ptonsparky
Tom
- Occupation
- EC - retired
Why do you think there is a problem? Something brought this up.
4x4dually
Senior Member
- Location
- Stillwater, OK
- Occupation
- Electrical Engineer/ Ex-Electrician
Well I'm just confused. 
how so ?Well I'm just confused.
4x4dually
Senior Member
- Location
- Stillwater, OK
- Occupation
- Electrical Engineer/ Ex-Electrician
I guess I don't understand the statement "different size PHASE conductor for different circuits." I'm not getting a visual as to what this means.
A 20 amp and a 30 amp circuit in the same conduit, for example. Assuming no derating for more than 3 CCC or upsizing for VD, that would give you #12 and #10 in the same conduit.
The OP has probably asked this question before and the answer can be found in 300.3(C)(1). It can be multiple circuits from the same system, it can also be something like a 480V MWBC and a 208V MWBC. The answer can also be found in 250.122(C).
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