I am reviewing a job that another engineering firm did. 1999 NEC is code for project.
The electric wall heater is a 4kw at 208v/1 phase.
So i get 4000/208= 19.2 amps x 1.25=24 amps for branch overcurrent and branch conductor.
So normally I would use a #10awg. But they selected a #12awg. table 310.16 has asterick next to #12 which the note says see 240-3. 240-3(d) small conductors states that a #12 can be protected by 20 amperes unless allowed in e thru g.
g. does not have fixed electric space heating listed.
So I assume the #12 has to be protected by 20A CB max for this application. And a #10 should be used for the conductors.
What is your opinion?
The electric wall heater is a 4kw at 208v/1 phase.
So i get 4000/208= 19.2 amps x 1.25=24 amps for branch overcurrent and branch conductor.
So normally I would use a #10awg. But they selected a #12awg. table 310.16 has asterick next to #12 which the note says see 240-3. 240-3(d) small conductors states that a #12 can be protected by 20 amperes unless allowed in e thru g.
g. does not have fixed electric space heating listed.
So I assume the #12 has to be protected by 20A CB max for this application. And a #10 should be used for the conductors.
What is your opinion?