Operation of 240 VAC Appliances on 208 VAC

[ericlemmon1]

Many apartment houses, condos, cluster homes, and modular home parks are served with two phases of a 208Y/120 volt system. Since a 240-volt heating appliance such as a kitchen range, clothes dryer, or water heater will operate at 75% of rated capacity when fed 208 VAC, should it be required that outlets for such appliances be clearly marked to inform the owner of the reduced voltage? Also, since a 12kW range will require a 60 ampere branch circuit if run on 208 volts, should the NEC be updated to consider this?

 

[infinity]

Many apartment houses, condos, cluster homes, and modular home parks are served with two phases of a 208Y/120 volt system. Since a 240-volt heating appliance such as a kitchen range, clothes dryer, or water heater will operate at 75% of rated capacity when fed 208 VAC, should it be required that outlets for such appliances be clearly marked to inform the owner of the reduced voltage? Also, since a 12kW range will require a 60 ampere branch circuit if run on 208 volts, should the NEC be updated to consider this?

Do you have a calculation for this?

 

[iwire]

Many apartment houses, condos, cluster homes, and modular home parks are served with two phases of a 208Y/120 volt system. Since a 240-volt heating appliance such as a kitchen range, clothes dryer, or water heater will operate at 75% of rated capacity when fed 208 VAC, should it be required that outlets for such appliances be clearly marked to inform the owner of the reduced voltage? Also, since a 12kW range will require a 60 ampere branch circuit if run on 208 volts, should the NEC be updated to consider this?

All residential electric ranges, dryers and water heaters that I can recall had two ratings, one at 208 and the other at 240.

 

[ptonsparky]

they just aren't going to get as hot. Maybe it will keep the pork chops from burning and the delicates from melting...or at least take longer.

 

[kbsparky]

...Since a 240-volt heating appliance such as a kitchen range, clothes dryer, or water heater will operate at 75% of rated capacity when fed 208 VAC... Also, since a 12kW range will require a 60 ampere branch circuit if run on 208 volts, should the NEC be updated to consider this?

You answered your own question in your original stipulation --- such appliances will operate at 75% of their rating. Therefore, a 12 kW range will now be a 9 kW range, and at that level will only require 43? Amps at max capacity.

Even at that, I believe that a single range is allowed to be supplied by a 40 Amp circuit.