plc 115vac input

[rick62]

I keep losing this input on an dl06 automation direct plc, all inputs are 115vac, all of the other ones are ok, just one that I have had to move twice to another input- what is the best way to protect your 115 vac inputs from failing.

 

[rpoet]

I keep losing this input on an dl06 automation direct plc, all inputs are 115vac, all of the other ones are ok, just one that I have had to move twice to another input- what is the best way to protect your 115 vac inputs from failing.

What is that input coming from? Can the device you're monitoring create an inductive spike when it turns off? Can you use an interposing relay on that input?

A properly rated MOV in parallel with the input, and connected to ground may help.

-rpoet

 

[T Gibbs]

I've had that happen on a DL06 3 or 4 times in 2 years. I still haven't found the cause of it.

 

[Mike Nash]

This thread on Automation Direct's customer forum may help some. It is about this same problem on the same PLC.

https://forum.automationdirect.com/forum/general-applications/13475-inputs-being-fried

 

[Cow]

Since we're talking about it, can anyone recommend a MOV or snubber they'd recommend to put across the coils?

I tried picking one out on Mouser a few weeks ago, but all the choices are overwhelming.