You get it, Winston. For Dave to hold onto the hope that a thermal protector
from a refrigerator or window A/C unit will suffice for his (greater HP) air
compressor motor, isn't likey to happen.

The peak starting current drawn by the air compressor motor will far exceed
the peak starting current of a fractional-HP household refrigerator or
window A/C unit.

The compressor motor's nameplate shows the HP as 4.0SPL (spl special). The
2-cylinder pump on the compressor can most likely easily be run with a 2 HP
motor (I owned a similar new compressor from Sears about the same time Dave
bought his), which is still considerbly larger than the motors in a typical
residential 'frige or window-sized A/C unit.

It's just far easier to get the correct part, which will fit properly inside
the motor (the only place it should be installed), and have the proper
protection.

I don't believe I've ever purchsed anything with the expectation that it
should or would work properly for over 30 years.

I could see myself using a 240VAC-rated TP device inside the motor, wired to
a properly-rated motor starter (inside a metal box) and secured to the
compressor.. IF a perfect replacement for the original part was NLA no
longer available.
But this method would very likely cost several times more than the
replacement part.

A lower voltage TP device (120VAC or lower starter coil control voltage)
would require the power cord to have a neutral conductor, and possibly a
stepdown transformer, to be wired properly.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Winston" wrote in message
...
dave wrote:
Wild_Bill wrote:
You've certainly got your money's worth out of the compressor in the
time you've owned it.
not quite yet...

The cost of the thermal protector is small
compared to a new motor, or new compressor.
well, yeah, bill, but I'm still shopping. the deal is, though: in the
entire 34 or 35 years i've owned it, I don't recall *EVER* pressing the
thermal reset button. and now, all of a sudden, right after I finish the
days spraying, whamo! it kraps out. compressor was indoors, in the shade,
same ventilation as usual, same cords and breaker, ambient air temp same
as usual, everything 'as usual' (except the "failed open" that is).

I have the thermal protector 'jumped' now, I soldered a heavy wire across
the klixon termnals (though couldn't say for sure why I didn't just
REMOVE the thing entirely, and REPLACE it with the wire)

Wild_Bill speaks the truth.

We know that the protector actuated once, Bubba. It saved you
a motor. You've finished troubleshooting but you haven't started
the repair yet! Please consider replacing the thermal protector so
you can get another 35 years safe use from your compressor.
Think of it as an insurance policy on your motor that costs
$0.86 per *year*.

Thanks!

--Winston

--

In the middle of some desert, is a gigantic pile consisting
of nothing but your ballpoint pens and spray bottles of
glass cleaner.