ktmrfs wrote:
2112 wrote:
More R = Less Load
An ideal 1500W heater would have a resistance of 9.6 ohms. At an ideal 120VAC it will draw 12.5A. Let's say an extension cord adds 1 ohm. Now R = 10.6 ohms.
120V/10.6 = 11.3A
120*11.3 = 1356W
The extension cord changed a 1500W load to a 1356W load.
a 40ft 12ga extension cord has a total resistance of 0.12 ohms.
now resistance is 9.8 ohms, or 12.25A or 1470 watts.
not much of an effect.
My apologies if this was misleading. I was using hypothetical values for the sake of discussion. I didn't bother looking up R/Ft of various wires. I guess I could have said "Let's say a 333' 12ga extension cord adds 1 ohm".
The connectors will add resistance as well. Especially after they age and wear from use.
