Answer 1 = #10 4500/240*1.25 = 23.44 amps. next wire size is 10

second answer same math =31.25 amps so next wire size is #8.

Ok so here is a trick question residential range 12,000 watts at 240 volts. I'll give you the answer you tell me why. 8000/240 = 33.33 or #8 Hint answer is in section 8

In NEC if a load is continuous you must use wire size and overcurrent protection rated for 125% of the nameplate rated ampacity. If I recall a continuous load is one that will be in use for 3 or more hours consecutivly.

Jimmy

Life is tough, Life is tougher when you are stupid

A continuous load, under 225 amps, is a total of 1 hour in any two hour period, under normal operation. If you normally operate your drier at high heat for more than one hour at a time, it might be continuous. Unless you have a commercial dryer, the element will cycle, and it probably isn't continuous. In my home, the dryer runs for a few hours on the weekend, so the normal operation is off. Since I can select "any two hour period", I'll pick a weekday. It clearly doesn't say "every" two hour period.

A 12 KW range in domestic use is considered to have a 8000 watt demand see 8-300. This is why we use 8-3 instead of 6-3 to feed a 12 kw range 8kw=33.33 amps on a 40 amp breaker 12 kw = 50 amps and in a commercial application X 1.25 or 62.5 amps on an 70 amp breaker The range itself is different too. A domestic range while capeable of using the full 12 kw with all 4 elements and both oven elements on high it does so for ver brief periods. Domestic ranges are not approved for use in a restaurant even though they often try to use them since they are 1/4 the cost.

The commercial range is rated for use the whole day, every day.