What amperage are 15 kw heat stripps suppost to run at,,,Right now they are running at 21 amp,,,is that to high

Are you sure these are 15 KW strips? How about 1.5 KW strips?

Power (watts) = volts * amps.

15000 watts = 120 volts * A
15000/120 = A
125 amps = A (kind of high, I think).

If it's a 240 volt circuit
15000/240 = 62.5 amps

If it were a 1.5 kw circuit
1500 / 120 = 12.5 amps
1500 / 240 = 6.25 amps

If it's a 1.5 kw strip, and it's pulling 21 amps, it's probably faulty. It's too high regardless of the voltage being applied.

If you have a 15 kw heat package with three 5 kw strips at about 240v, 21 amps is about average (per strip).

5000 watts / 240 volts = 20.8 amps. That makes sense.

5000 watts / 240 volts = 20.8 amps. That makes sense.As always, great minds think alike...;)