[Milsurplus] HOT PE-73 Contactor solenoid Redux

[WA5CAB at cs.com]

Jim,

First, if you can get it apart to rewind, you can measure the wire diameter 
and count the turns as you unwind the old wire.  No need to calculate 
anything.

But if you have to go for a generic replacement, the PE-73's rated Full 
Load Amps is 20.  The starting surge current will be typically three to five 
times that.  But this is much less important with relays than with power 
supplies.  So long as the relay closes firmly and quickly with no contact bounce, 
it's the continuous current while running, and the current and supply 
voltage at opening that are important.  I would suggest a relay rated 30 or 35 
amps @ 28VDC, continuous duty.  Do NOT buy an automotive or aircraft engine 
starter relay.  They are normally rated for intermittent duty with a very low 
duty cycle.

In a message dated 07/25/2011 05:39:06 AM Central Daylight Time, 
ka2ivy at verizon.net writes: 
> Laura and Jim wrote:
> >Confirmed that the contactor assembly is a 28VDC one and completed 
> testing it today. It is the solenoid winding that gets hot. Ran it by itself 
> w/28VDC on it; clicked shut and it heated up in a couple of minutes. 
> Disconnected power from it and jumped the contacts. Ran just fine after yelling into 
> the aether for a half hour yesterday night. Barely warm to the touch. PS - 
> Thanks for the "remove the end-bells" comments. Works very well and the 
> dyno is happy.
> >

> >So........Mouser or Allied? Any recommendations? Even better - any 
> spares? If I knew the specs (resistance, amps), maybe I could disassemble the 
> unit and re-wind the solenoid myself......?
> >
> >Cheers!
> >
> >Jim Falls
> >K6FWT
> >Eureka, CA
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Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480