PDA

View Full Version : Quick question, no pic


Ross Neag
12-10-2010, 02:54 PM
Is 12awg stranded copper acceptable for a 25amp Type S fuse? Can find anything on it. TIA...
Jerry Peck
12-10-2010, 03:58 PM
No.

The maximum allowed overcurrent protection rating for #12 AWG is 20 amps.

(Unless that is for an air conditioning unit and the nameplate says otherwise, but I doubt that is for an air conditioning unit.)
H.G. Watson, Sr.
12-10-2010, 04:20 PM
What's the application (load type, etc.) and wiring method? Componant, house wiring, RV, sound system, amplifier, etc.?

In free air, metallic conduit, cable assembly?

Why "S" and not "SL" or other more time limited?
Ross Neag
12-10-2010, 04:30 PM
It was for common area lighting of 2 unit (used to be 4 apartments) vintage condo. I called it out but 'likely' has minimal load. Was in EMT, no labeling as to function on panel.
H.G. Watson, Sr.
12-10-2010, 05:01 PM
Thats no good. No to outlets & lights.

Direct to equipment, motors and such can be okay.

Here's a link to a well written example of #12 awg 75C conductors & equipment used at 25 amps protected by 45 Amp Breaker.

You might find the discussion on the short topic string interesting:
#12 AWG on 25 amp OPD - Electrician Talk - Professional Electrical Contractors Forum (http://www.electriciantalk.com/f2/12-awg-25-amp-opd-13748/#post229375)