> If you can't measure current, you could check coil resistance with
> the solenoid
> disconnected and manually moved. Unfortunately I've never seen any specs
> for current draw or resistance of the coils.
The pull-in coil draws 15-20 amps, so it's resistance is around 0.7 ohms.
Holding coil draws about 1 amp, so it's resistance is around 12 ohms.
Even with only the holding coil energized, the solenoid will grow quite warm
to the touch after some time. The pull-in coil will overheat in a matter of
minutes if continuously powered.
In normal operation, the solenoid plunger moves only a small distance (about
5/32"), and it's somewhat cushioned by the linkage to the operating valve.
I'm not certain, but I have a suspicion that over-enthusiastic bench testing
of the solenoid may lead to shortened life ... on the newer solenoids it's
only a bit of nylon that the plunger hits to move the contacts and being
slammed into may well deform the nylon.
Randall
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