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AC relay chatter

Michael H

Sep 7, 2012
1
Joined
Sep 7, 2012
Messages
1
Hello all,

I have a pump control circuit that is causing relay chatter. It appears that R2 is getting enough current from the SSR timer to cause R2 to chatter. The circuit functions properly when the float F2 is in the high position, but when it's in the low position and F1 is made, that's when it chatters and actually causes the processing pump to pulsate. The reason for R2, is to control a solenoid valve to the open state, but only after the SSR timer times out.

Any help is greatly appreciated.
Circuit drawing attached

Thanks,

Michael
 

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shrtrnd

Jan 15, 2010
3,826
Joined
Jan 15, 2010
Messages
3,826
I use a varistor across the relay input power circuit. A lot of people on this forum prefer
using diodes.
Google the problem and determine what you want to do.
I've heard others complain that varistors (which electrically are back to back diodes)
don't have the life expectancy of diodes, but I rarely experience problems. I suspect
that they might be underrating them when they chose them for the application.
It is important to remember that varistors are intended to limit voltage spikes in the
relay coil back emf. Check the data sheets and design for peak voltage spikes,
not RMS.
That's my opinion, I expect you'll receive others. Good luck.
 
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