On the 240v circuit, the voltage is higher and the current is lower. But, you are still limited to 2000 watts on a 20 amp breaker and 1500 watts on a 15 amp breaker.
Wait a minute.
240 x 20 = 4800 watts
120 x 20 = 2400 watts
Hit it with the 80% for continuous load and your looking at 3840 or 1920 watts.
