Safe to use 220V electric clothes dryer when building has been bridged down to 110V?

Question

We live in a building with 220V service with primarily 110V outlets but a few specialty ones at 220V.

Earlier this week electrical service in half the building across all three apartments went out. The utility company came out on an emergency basis and restored power by bridging one of the 110V wires onto the faulty one.

Now the lights are back on but the 220V outlets are presumably only offering 110V. It is safe to run a 220V electric dryer on an outlet that now offers 110V of power?

I called the manufacturer of the dryer (Samsung) and all they knew how to do was look up stuff in the manual, which was not helpful. The emergency service technician (not a electrician) was not certain either. I called an electrician and he didn't seem certain either, but recommended against it to be on the safe side.

From the research I have done it seems like the concern might be that the motor might burn out possibly and that definitely the heating element would not get as hot so it might take a lot longer for a load to dry. I can live with the latter but not the former. Additionally are there any safety issues to consider?

I tried the dryer for a moment and the panel lit up and the drum spun as expected. Did not test to see if it got hot.

Repair service is a scheduled for a week away and the laundry is piling up! Even when they attempt repair they are counting on running a new wire through the underground conduit which I already suspect is not sound so they may have to dig which will surely take longer.

Answer 1

It won't work. Your 220V (really probably 240) outlets will actually have 0V, not 110V.

The reason for this is that normally the 220V outlets make their 220 by taking both 110 lines that are out of phase with each other, such that while 1 is at +110, the other is at -110 for a difference of 220. Since the power company bridged one of the 110 lines to make up for the dead one, that won't work -- they'll both be at +110 or -110 at the same time, for a difference of 0.

Answer 2

Most North American style dryers will work on 120V power one of two ways:

Make both hots (the same pole of) 120V, neutral is neutral

In this case, the 120V equipment on the dryer will work. It is not guaranteed to be this way, but likely it will be the timer, controls, blower, and tumble motor. So it can "air fluff".

However, the heat will not work at all. So all you get is air fluff.

This is the setup you are getting by default, due to the way the power company has emergency-bridged it.

Move one hot to neutral

And this modification should be done inside the dryer not by altering the plug or socket. The dryer should be rendered safe in any case, so that nothing spits and sparks if power changes. E.G. Don't lug both of the cord's hot wires together.

In this case, you pick the right hot wire (on the dryer's side) and move it to neutral. If the tumble motor/fan/controls stop working, you picked the wrong hot. Undo it, then use the other hot.

At this point, the tumble motor and fan will work, as will the controls (on most dryers).

Heat is a bit of a problem. It will work, but only at 1/4 power. This is better than nothing but expect drying to take awhile.

By the way, this will require less than 20 amps of power. You could make a dryer work this way on a 120V/20A circuit, because it would draw less than 16A (80%). You would have to measure to see if it uses less than 12A (80%) before putting a common 15A plug on it.