Message text written by "Chris Jameson"
>Could someone please tell me how to measure the current with a multimeter
with the solenoid in situ? I am quite happy with voltage and resistance,
but current measurement is not on my list of multimeter skills..
<
There are two ways. One involves a meter witha 10 Amp range. Not very
many cheap meters have this provision, they usually top out a 1/2 amp.
Don't try one of these, you'll blow the internal fuse and get no worthwhile
information in the process. If you meter does have a 10 amp range,
disconnect the coil and wire the meter up in series with the coil and
switch on the solenoid.
If you meter does not you could get yourself a low value resistor such as a
0.5 ohm, 2 watt resistor and measure the voltage across it when the
solenoid is powered up. You can calculate current by dividing the voltage
reading by the resistance (Ohm's law: i=e/r).
Perhaps the easiest way is to get an in-line fuse holder and a 2 amp
slow-blow fuse (such as an MDL-2) and wire that in line with the solenoid.
If the adjustment is right the fuse will stay intact. If the pull-in coil
is not getting disconnected the fuse will blow after a few seconds. If the
fuse is fine after a few minutes you can rest assured everythign is OK.
Oh, and leave the fuse in there just in case something happens. It could
save your solenoid.
Dave
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