E stop relay 24VAC supply voltage?

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Craig
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E stop relay 24VAC supply voltage?

Post by Craig »

I don't understand this, it seems very odd to me that it's asking for 24VAC, I don't even know where to get that from? What am I missing? I can get 24VDC from the invertor or Centroid power supply, but AC?
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tblough
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Re: E stop relay 24VAC supply voltage?

Post by tblough »

AC...DC...Whatever it takes. Seriously, it doesn't matter as long as the contactor coil is rated the same. Many moons ago before electronics, machines used 24VAC from a transformer for control circuits. Now that we have DC power supplies for other items, we use 24VDC for control circuits.
Cheers,

Tom
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I have CDO. It's like OCD, but the letters are where they should be.
martyscncgarage
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Re: E stop relay 24VAC supply voltage?

Post by martyscncgarage »

The reasoning behind the 24VAC coil was that in earlier days, Centroid would purchase transformers for the DC Buss power supply for the DC servos and it was trivial to add a winding for the 24VAC circuit. As Tom suggested, no issue using a 24VDC contactor but do not use the controls logic power supply to control it. Buy a 24vdc power supply. OR if you want to stick with the Centroid 24VAC standard. I have used these in the past in keeping with the schematic:
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JasonPORC
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Re: E stop relay 24VAC supply voltage?

Post by JasonPORC »

Craig wrote: Wed Feb 10, 2021 1:47 am I don't understand this, it seems very odd to me that it's asking for 24VAC, I don't even know where to get that from? What am I missing? I can get 24VDC from the invertor or Centroid power supply, but AC?
I had the exact same question! Thanks for asking it. It was on my list of “questions to ask” once I dug a little deeper into the project. Glad you beat me to it. :) the answers below all make perfect sense now. Cheers
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