We have found ourselves in a spot where we are going to have to live in our camper for a bit and need to purchase an extension cord that will reach the closest power. I am looking at a heavy duty 100...
In that case the heater that does 900 watts may only output approximately 684 watts at 105 volts input.
Label output errors have nothing to do with what I was trying to explain, which that voltage drop for resistance heating devices make a large difference in "real" output.
It is one reason I tend to use an autoformer even in winter.