This question pertains to a 480V, 3 phase, 4 wire system. I have a 60A welding receptacle hooked to a 50A breaker with appropriate sized wire (#8 THHN). I'm about to install a portable heater rated at 18Amps max. The unit will have a 30Amp fused disconnect mounted on it. My question is as follows: Can the cord hooked to the disconnect and plugged into the 60A welding outlet be sized for a maximun draw of 30Amps, or, does it have to be sized per the breaker? Between Article 240.5.(B)(1) and Table 400.5(A) and possibly Article 210, I'm not positive what the answer is. NOTE: These heaters are moved to different locations from time to time due to the fact they are on wheels. The only power available at all locations are these 60A outlets. The units are being fused with 20A slow blow fuses, as per required from the manufacturer.
[ January 03, 2005, 12:09 PM: Message edited by: croecken ]
[ January 03, 2005, 12:09 PM: Message edited by: croecken ]