# Is kickback protection needed on small 120v coils?



## emtnut (Mar 1, 2015)

TheWireNut said:


> Doing a small panel with 10 ice cube relays and a couple of timers for boiler controls. Is there any need for suppression on the small coils in the relays? One is driven by the boiler controller. All loads are either other relays themselves or small single phase circulators and zone valves. I only know of diodes protecting DC coils but am not sure if AC what to use on AC. This is cycled about 20 times a day, and the controller is very expensive, want it to last.
> 
> TWN


I have seen RC snubbers when using AC coils.
They can reduce inductive kick back.

This is not for the AC coil though ... I would be for the contact controlling a solenoid, small motor or pump.

You can put the snubber on the AC coil as well if it's an inductive load


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## joebanana (Dec 21, 2010)

I would think the controller would have built in protection, but then I would also consult the manufacturers literature. (if all else fails, read the directions)


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## AK_sparky (Aug 13, 2013)

buy relays with built in protection.


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## I&ETech (Mar 30, 2016)

We use MOVs wired across the relays contacts that are switching inductive AC loads.


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## JRaef (Mar 23, 2009)

It's not the coils that need protection. It's other things on the same circuit that need protection from the inductive kickback of the coils, even on small relays. It's not as bad, but it's still there. So what else is on that circuit? If it's just other relays and contactors, then no. If it's anything electronic, like your controller (assuming) then yes. MOVs or RC Snubbers on AC coils.


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## TheWireNut (Apr 20, 2014)

Yes the controller is on the same circuit. It is of Eastern Europe decent and the instructions are a bit on the lean side as well as the entertaining broken English translation. 

The protection of the controller is what I meant in the OP. Thanks all, will be installing snubbers at the relay bases.

TWN


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## JRaef (Mar 23, 2009)

TheWireNut said:


> Yes the controller is on the same circuit. It is of Eastern Europe decent and the instructions are a bit on the lean side as well as the entertaining broken English translation.
> 
> The protection of the controller is what I meant in the OP. Thanks all, will be installing snubbers at the relay bases.
> 
> TWN


Ooooh... Eastern European! 1970s technology then... protection of it is a must, and I'd start thinking about replacing it now if it were me.


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