Re: Volt-amps BS


"Chris" <cfoley1064@xxxxxxxxx> wrote in message
news:1175357592.122214.249990@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Mar 31, 10:53 am, "Michael" <newsz...@xxxxxxxxx> wrote:
Some of these industrial ratings want to make me pull my hair
out.....horsepower....volt/amps.....I've never bothered to commit any of
it
to memory.

Could some please tell me...

If a relay has a 24vac coil and a "hold VA" of 15. what does that
translate
to in current draw at 24 volts? Who knows what they're talking
about.....I'm
sure the relay probably kicks in around 18 volts or so. I'm just trying
to
get an idea of the transformer I'll need.

Thanks. !

Hi, Michael. AC relays and solenoids are constructed differently than
their DC counterparts. If you'd like, try to run a 12VDC coil relay
with 12VAC. You'll just create a buzzer. AC relays have shading
rings to counter this effect.

An AC relay or solenoid draws a heck of a lot more current when it's
pulling in (sometimes called "pull current") than when the plunger or
relay actuator is in place. This lower current is called the "holding
current".

Can you explain a little about how the AC relays work a bit? I'm confused
because it would seem that only DC would work unless there was some sort of
rectification inside. What are these shading rings and stuff? (I tried
searching but really can only find info on "DC" relays)

Thanks,
Jon


.

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