240v is the line to ground of a 415 240y system.
Will a 240v heater run on 208v.
20a x 208v 4160 watts.
Say the tank draws 20 amps.
When you run 120 208v single phase power into an isolation transformer the two individual hot conductors of 120v are combined into one 208v waveform.
220v is a line to ground voltage of a 380 220y system.
Therefore if you put 120v in you will get 120v out 208v in gets you 208v out 240v in gets you 240v out etc.
Some motors are actually dual rated for both 50 and 60 hz with corresponding different speed and amp ratings.
It is more likely a 208v 230v or 240v motor.
20a x 240v 4800 watts.
It will take longer to heat your water with less wattage.
Can you run a 240v clothes dryer on a 208v 3 phase connection.
For example 120 240 and 120 208 both provide 120v on standard receptacles but when using a dryer or hot water heater for example that appliance would be using 240v or 208v respectively.
Putting it all together.
208v commercial electric water heaters previously purchased great for a variety of commercial installations these efficient units are built to last providing temperature controlled water where and when it s needed.