240.4(b)

[ibew501ed]

A question can up , can 7 -9 current carrying # 10 thhn 90 deg C be landed on a 30 a ocpd. 310.15(b)2a states 70%. therefore 40a #10 X 70% = 28 amps,
does 240.4b move the ocpd to 30 amp if the circuits are not part of mwbc, for example 4 220v heater circuits 24 amp max load ( I say why not?)
thanks in advance

 

[iwire]

Yes you can roll up if you meet the conditions but in your example the calculated load would have to remain under 28 amps.

 

[infinity]

A question can up , can 7 -9 current carrying # 10 thhn 90 deg C be landed on a 30 a ocpd. 310.15(b)2a states 70%. therefore 40a #10 X 70% = 28 amps,
does 240.4b move the ocpd to 30 amp if the circuits are not part of mwbc, for example 4 220v heater circuits 24 amp max load ( I say why not?)
thanks in advance

Actually a MWBC has nothing to do with the requirement to go up to the next standard size OCPD.

 

[Pierre C Belarge]

Actually a MWBC has nothing to do with the requirement to go up to the next standard size OCPD.

When I am teaching out of the NEC, I try to help the guys to read what is written, not what they are used to hearing/seeing.

Multiwire branch circuit

Multioutlet outlet branch circuit


It is not difficult when reading to mistake the two, and we see it all the time.

 

[ibew501ed]

correct I ment multi outlet TY