Greetings:
I have a shaper with a 3 ph 380 v 50 hz motor equipped with a circa 1970's Siemens magnetic contactor switch. The contactor has a coil which is energized by a remotely mounted switch. My problem is that the contactor does not close when the coil is energized by the remote switch. The coil circuitry reads 27 volts, the coil is marked 220v 50hz. The contactor stays engaged when pushed in by hand, and the shaper works as designed until switched off. Only the remote switch The coil has two wires, 100% resistance (zero continuity) when measured across the two wires. One coil wire is attached to a thermal overload device mounted to the magnetic contactor, which appears (at least mechanically) to work fine.
The magnetic contactor has a label stating that one should look at the coil to ascertain control voltage. I have read on the internet that control voltages will often be lower than mains voltage, using a step down transformer. I have looked all over the machine and can't find a transformer. I can't figure out why there would only be 27 volts in this particular circuit... all wiring is in good shape with no breaks externally evident, and no transformer. I'm tempted to supply 220 v to the coil (after all, it's labeled 220v), but want to refer to the expertise here on the newsgroup before I chance burning the coil. Would zero continuity indicate a bad coil?
There are other circuits present on the machine in the form of on / off switches related to table travel. All have 220v. The only place 27 v is present is in the circuit that energizes the coil. The reduced voltage makes sense to me, since it would seem unwise to supply 220v to a remotely mounted control switch that is, literally, the closest the operator comes to the electrically energized parts of the machine during use. The remote control switch is normally off, spring loaded momentary on when pressed by the operator.
Regards, Jim Brown