[Shop-talk] Air compressor hook up

[David C.]

Sorry if this is a duplicate post but I don't know if the previous post 
went through.

I'm replacing my old 3 HP portable air compressor with a 5 HP vertical 
stationary model.  The old compressor has a lever on the pressure switch 
assembly so I can switch it on and off and I normally leave it off when I'm 
not in the shop.  The new compressor has similar pressure switch but no 
lever.  For the time being I guess I'll switch it on and off at the breaker 
as I don't want to leave it energized when I'm not in the shop, which is 
mostly on weekends.   There's no reason to keep it energized and 
pressurized when I don't need it.  None of the hardware stores sell a 
separate disconnect (other than an AC "pull out" disconnect) so I wonder 
what you folks do?  Will I  have to go to Graingers and get a disconnect 
switch?

The thing was also shipped, according to the manual, without oil, although 
a little is showing in the sight glass.  The instructions said to use ISO 
100 compressor oil, single weight non detergent motor oil (no weight given) 
or 5w30 or 10w30 Mobil 1 Synthetic.  That seems mutually exclusive as ND 
oil is designed to let the crap and particulate settle into the crankcase, 
and multiweight automotive motor oils are designed to keep it all in 
suspension so the oil filter (which the compressor doesn't have) can filter 
it out.  I was able to get a couple of quarts of "compressor oil" but I 
suspect 20 or 30 ND would work just as well.  Any opinions?