Jeffrey Angus wrote:

Just a few abstract thoughts here. It makes sense to me,
but then I've been known to over look the obvious on
occasion. ;-)

I have a solenoid coil that actuates a large 3-pole
contactor. A short pulse to pull up on a lever that
will toggle it from on position to another, and back.

Making measurements of the solenoid coil, although
potted in epoxy, yields a few measurements and a
couple of guesses.

http://www.pronine.ca/multind.htm

Coil form 1" diameter, 1-3/8" width and 1.5" depth.
Going backwards on a solenoid coil java script, yields
a matching 125 mH inductance (as measured) and 95 ohm
DCR (as measured) for 2500 turns of #30 AWG which will
fill the bobbin.

This a 480 VAC actuator.

Am I headed in the right direction if I assume the key
factor here is ampere turns?

Not allowing for the added inductance by a movable core,
this has an impedance of roughly 100 ohms. So that works
out to 4.8 amps or 12,000 ampere turns.

Substituting 2000 turns of #28 AWG yields 80 mH, and 42
Ohms. And subsequently roughly 12,000 ampere turns at
240 VAC.

Putting 240 VAC across the 480 VAC coil yields only 6,000
ampere turns and obviously is NOT enough to actuate the
contactor transfer mechanism.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

Jeff-1.0
The other other one

Beware that some coils are dual coils with diodes potted in them.

WHen a diode fails in one of these, they tend to generate some noise
when energized. This is because one coil is pushing both directions
against the other that isn't.

Basically what this means is, the coil is designed to operate in a
DC state.

What we have done in the past if we suspected a shorted diode in one
of these types is to put a bridge rectifier in front of it.

But I can tell you this, if the construction of core around this coil
in the device that is using it has a laminated type layers, chances are,
you have a simple coil and there is some form of shading device near the
contact point where the accouter makes contact with it.

What is this thing? A ratcheting three position device? being ASCO, it
sounds like some kind of valve.

Jamie