Moving to California – 110V not the whole story

Posted by Jonathan on July 29th, 2007 filed in Voltage Conversion

When we left the UK, we left behind a truckload of 240V appliances, toasters, drills…
you name it, there was a lucky and happy recipient!

We would need to buy a set of expensive converters to run it all and didn’t like the thought of spending more
on a voltage converter than the actual appliances just to run them.  We kept one Bosch rechargable hammer drill which had been a fabulously reliable workhorse (I figured this one was worth buying a converter for – plus the charger could sit in the garage out of the way).

Of course we left it behind because America runs on 110V, right?
Well, actually that’s not the whole story.

When we bought our own home in SoCal and bought a book to figure out the electrics, I realised that
there are a pair of feeds brought in to the house.  In the UK, there is a single 240V feed which swings
from -120V to +120 compared to ground potential.  Naively I figured that 110V means +/- 55V swings and that was it.

Doh!  Actually there are TWO 110V feeds of opposite polarity.  Three wires enter the home – one at ground potential, one 110V AC and the other 110V AC with the opposite phase.

Hence put something across both 110V feeds and you have 220V!  Really really wish I’d known that.
Turns out ranges (ie electric ovens) and other high power devices such as electric clothes dryers tend to use 220V.

The usage tends to mean that the only 220V points are in the garage and one under the kitchen counter – hence limiting the availablity of 220V points.  Naturally the 220V points are a completely different shape to the standard US plug so that you don’t fry yourself by plugging a lower voltage device into full blown 220V.

Yes, I know 220V @ 60Hz isn’t quite 240V @ 50 Hz but I know for sure I’d have been able to run some of the stuff we gave away.  Live and learn.