On Sun, 25 Jul 2010 13:44:54 +0000 (UTC), Elmo
wrote:

On Sun, 25 Jul 2010 05:41:59 -0700 (PDT), jamesgangnc wrote:
What you really need to do is install a dedicated 220 outlet

I agree that's the by-the-book method. However, the cost of having an
electrician replace the 30-amp NEMA 10-30R with a 20-amp NEMA 6-20R is more
than the cost of a compressor that runs off of 110.

Have you looked at the compressor to see if it can be run on 110?
I didn't realize the 30-year old Sears Craftsman compressor COULD run on
110. How would I know? (I'll try to dig up a model number and google it
after this reply.)

The safety issue is that you will be using your nuetral line
for a ground and using a 30 amp circuit where a 20 amp
one is called for.

But wouldn't the neutral line ALREADY be used as a ground in the NEMA
10-30R dryer circuit were I to plug in a dryer to that circuit?

Isn't the compressor the same as the dryer from an electrical standpoint
with respect to the ground/neutral wire?
Actually, the dryer may have an issue with today's code as it is
using the "ground" as a neutral for the 110 volt lamp, motor, and
timer circuits. Today's code (at least here in Ontario Canada)
requires a FOUR wire plug for dryers and other 220 volt devices that
use 110 volts as well.

The compressor is a straight 220 device - not requiring a neutral
(which is being "faked" on the ground on a 3 wire plug)