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Jeffrey Angus[_2_] Jeffrey Angus[_2_] is offline
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Default Re-winding solenoids.

On 10/16/2011 8:44 PM, Jamie wrote:
Then it must be pushing a large load a long distance.

at that current, you looks like you have ~ 100 ohm coil


Did you read the details from my original posting? (Se below)

which means the wire in the coil is rather a large gauge since
this is DC going to it.

I would start around 20awg and see what the DCR 1M is on the
chart. Then see if that will physically fit on the form.


I originally wrote:
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.


roughly 100 ohms, yes.

This is NOT a constant pull and hold solenoid. This is a
pulsed operation.

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.


Based on: Ampere turns =
(Applied voltage * number of turns)/(coil resistance)

Both estimations of the needed number of turns and wire size
seem correct.

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.


This tends to indicate that ampere turns is indeed the magic
number as 6000 is not enough to actuate a mechanism that
appears to require 12,000.

Jeff-1.0

--
"Everything from Crackers to Coffins"