"Todd Rich" wrote in message
...
DrollTroll wrote:
Awl --

With single phase, what are the pro's/cons with having a 3 ph compressor
motor with starting caps, vs swapping it out for a single phase motor?

The tradeoff I see is a wiring pita vs. the grunt/mechanical pita and $$
of
a single phase motor, with likely a modified mounting.

I would like to put the starting caps/running caps on relays, that switch
in/out, as well.

How big is it, and have you considered a VFD running your 3 phase motor
off of single phase power?

No, I hadn't. But it is an idea. About 5 hp.

Certainly caps will be cheaper, but wiring relays, start/run is going to be
a pain as well.
Plus, I will have to de-rate the motor, and possibly put a smaller pulley on
it.

Keep in mind that this is a scenario where the motor is starting under
near-full load, which might be some electrical wear/tear on a VFD.

At least I *think* it is starting under full load (tank pressure).
Is there a way to set up an air compressor so that the motor starts under no
load? Only with a clutch, I would imagine, or "almost no-load", where some
vent bypasses the compressor head to air, or sumpn, and then closes.

So much drama....
--
DT




I'm running a 15hp 3 phase motor on my compressor. Admittedly, I need a
100 amp line to do it though.