On 2009-03-05, DoN. Nichols wrote:
On 2009-03-04, Ignoramus16649 wrote:
On 2009-03-04, Elliot G wrote:

"Ignoramus16649" wrote in message

The question is what is "properly".

There may be a more scientific method, but that's what I have always seen.
Even the adjustable breaker on 150 HP pumps are often set by "experience".
Set it just high enough for normal operation, and if it ever fails
prematurely just bump it up a little.

Makes sense. This is not life support equipment. If the overload pops
one day when it should not have, not the end of the world.

Except if you are running it from a VFD (IIRC, a VFD was
somewhere in the equation), you really don't want the overloads popping
between the VFD and the motor -- and the VFD itself should perform the
function of the overloads as well.

As long as you are running it from three phase from a rotary
converter, yes you want the overloads.

I have more or less changed my mind, and am feeling rather good about
running it from a phase converter. It is quiet and reliable. If I
would run it from a VFD, which is still a possibility, I would not use
that motor starter for any purpose.

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