On Sun, 25 Jul 2010 05:41:59 -0700 (PDT), jamesgangnc
wrote:

On Jul 25, 2:06Â*am, Elmo dcdraftwo...@Use-Author-Supplied-
Address.invalid wrote:
I just want advice for the conversion I just did before I plug it all in.

Details:
1. I have a two-phase 220V Sears Craftsman compressor which uses a 220 volt
plug with one blade sideways (otherwise it looks like a normal 120V
grounded plug).

2. I have no sockets in the house which fit that 220 volt plug.

3. I have a three-pronged dryer socket in the garage with 220 volts (two
hots and a neutral).

4. I just attached a new 3-pronged male dryer cord to a female 220 volt
plug with the one blade sideways.

Before I plug in the compressor to the recepticle to the dryer cord to the
recepticle, would you have any concerns about safety or other?

I assumed the neutral in the compressor plug was the center wire (looks
like a ground pin) while I assumed the neutral on the 3-pronged dryer cord
is the L-shaped center pin. Is that the correct assumption for the shared
neutral?

Yes, the L shaped prong is the nuetral on a 3 wire dryer. The other
two are the hots. Your compressor more likely needs 2 hots and a
ground. While what you are doing is not exactly by the book it will
run your compressor. 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. What you really need to do is install a dedicated
220 outlet in the location of your compressor. Have you looked at the
compressor to see if it can be run on 110? Many motors have alternate
wiring that allows them to run on 220 or 110.
If it is a 20 amp 220 plug on the compressor, it would need 40 amps
at 110, which is very non-standard. Assuming the 20 amp plug is
already over-sized a bit, he might get away with a 30 amp 110 volt
circuit - which again is definitely "non-standard" in today's
residentiial wiring scheme.