I hesitate even posting this, but, here goes. I have been contacted by a fast food restaurant wanting to have some new equipment installed. The manager hands me a computer generated drawing with said equipment showing the electrical requirements. This drawing showed the equipment to be "208V single phase". I had never heard of such a thing. But, I thought, I don't know all that there is to know, either. The existing service is single phase 120/240. I thought at first that I would need a step down transformer (buck booster)to get even close to the 208. The owner later tells me that they already run 208V equipment. Well, if that's the case then aren't they actually running that equipment at 240V? Seems to me that that is more than a tolerable variance for a motor. Anyway, it turns out that some of the equipment they are wanting to add is actually dual voltage 208/230, so I can see running the dual voltage equipment @ 240V. Thoughts???
208 single phase???
- Thread starter jotw
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ibew501ed
Senior Member
- Location
- danbury ct/work in white plains ny
a wye connected 3 phase transformer with 120 volts to neutral, has 208volt phase to phase. If you connect equipment to 2 hot legs, it's 208v single phase. 230volt motors very often run on 208 volt configurations
- Location
- New Jersey
- Occupation
- Journeyman Electrician
You can't get 208 volts from a 120/240 volt, single phase service. Dual rated equipment can typically operate at both 208 and 230/240 volts. IMO straight 208 volt equipment cannot be used on a 240 volt system.
- Location
- Massachusetts
Some equipment can run or either 208 or 240, some should not and others just cannot.
I suggest contacting the manufacturer.
I suggest contacting the manufacturer.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
I agree. It is most important to know if it is a resistive/heating element, inductive/motor, or combo load that the equipment is.
(I hope I got this right)
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Your 240v loads will only see about 75% of their power at 208v and will be slower to work/heat.
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