On Tue, 27 Jul 2010 15:03:51 -0400, mm wrote:

You keep using "ground/neutral" wrt the receptacle.
I think you mean ground.

You are correct sir!

I only belatedly, half way through this thread, realized that the green
ground wire on the 240 volt compressor was connecting to the white ground
wire of the 240 volt dryer receptacle.

If a DRYER were hooked up, then that white third wire in the dryer
receptacle would be doing double duty as a ground (for the 240 volt
circuitry of the dryer) and neutral (for the 120 volt circuitry of the
dryer).

But, I learned in this thread, that the dryer receptacle in the wall has
its white ground/neutral wire hooked to ground in the panel. So, even
though that white wire does double duty (when a dryer is hooked up), for
the compressor, I'm hooking ground to ground so there is no additional
danger because current is not being carried in this ground wire.

Thanks for all your help. The compressor worked flawlessly when I hooked it
up. I only got one comment on the pictures of the adapter so I'd appreciate
if anyone could tell me how to improve it.

A picture of the adapter cord and compressor is he
http://img534.imageshack.us/i/006ary.jpg/
http://img153.imageshack.us/i/005tqn.jpg/
http://img714.imageshack.us/i/004wtt.jpg/
http://img525.imageshack.us/i/003zpn.jpg/
http://img809.imageshack.us/i/007pet.jpg/
http://img828.imageshack.us/i/002nd.jpg/
http://img265.imageshack.us/i/001aaz.jpg/