On Fri, 30 Dec 2005 12:26:21 -0500, "Bob Chilcoat"
wrote:

I am building a new compressor from a salvaged C-H tank and other parts, the
99.99 5 hp pump from HF, and a new 5 hp, 1 ph motor. The new motor is too
much of a load for the pressure switch. I can get a contactor from Ebay,
but I can also get some 25-amp solid-state relays a lot cheaper. Anyone
have any thoughts on this option? The motor has built-in overload
protection, so that's not a strong consideration.

Not a good application for 25-amp SSRs. Start current on an
induction motor, particularly one with a compressor load, can exceed
10X rated load current. SCR's and triacs can take that for a cycle
( 1/60 sec) or so, but a compressor motor can take a significant
fraction of a second to get started.