Contactor coil: 50 Hz vs. 60 Hz

I may be able to obtain a very small 2-pole 240 vac contactor I need rated for 50 Hz only.

If I install it in N. America, what's the implication? Is the hold-in magnetism less than if it were 60 Hz? Just noisy?

Please don't ask or suggest other sources. This is a very specific device and I've not been able to locate other than this.

Thanks, Dave

Reply to
DaveC
Loading thread data ...

d

and

IME relays pull in at in the region of half rated voltage, and dc ratings are typically about half the voltage of the ac rating, which gives an idea of how much current is determined by L and how much by R. Running your relay on 220v 60Hz it will work fine. Contact closing speed will be slightly slower. Margin will be reduced, but its only being reduced from enormous to slightly less enormous, so its a non- issue except in very unusual situations. The vibration tolerance of the contacts will be little affected in practice; if your environment is harsh enough to shake the relay contact open, then you've got bigger worries than contacts crackling.

If instead you meant you would use it on 110v 60Hz, then dont. But you could use diodes to get a higher dc voltage and use that.

NT

Reply to
NT

ted

NO NO NO! DC excitation of an AC-rated coil is never a good idea. DC coils and DC-activated relays are designed very differently from their AC cousins.

Reply to
whit3rd

NO NO NO! DC excitation of an AC-rated coil is never a good idea. DC coils and DC-activated relays are designed very differently from their AC cousins.

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

As long as you alter the voltage to take into account no inductive effect, its probably not as bad as running a DC contactor with AC.

Reply to
Ian Field

There's a subtle difference, though, in an iron pole piece that gets permanently magnetized by repeated DC excitation, and the same pole piece that gets AC and is repeatedly demagnetized. I'd worry about the DC causing, maybe after weeks, a failure of a perfectly good AC component.

The 'no inductive effect' means that only the wire resistance, not the resistance plus inductance, limits field current. That means the field current with DC isn't predictably proportioned to the field current with AC (though THAT could be quickly tested).

Reply to
whit3rd

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.