Same relay contact wiring to PLC in parallel to solenoid

[NoviceInstrum]

Hi
I have a solenoid wired to a trip relay contact which is programmed to trip on high temperature. The trip relay is having only single contact. Now I would like to wire this trip relay contact to a Allen Bradley MicroLogix PLC so that I know when the solenoid is tripped via the relay contact. I am planning to connect the contact to PLC's digital input as per the attachement. I think it should work. Your comments please.

 

[itsmoked]

No attachment..

Probably NOT a good idea because the solenoid will be generating occasional LARGE spikes when de-energized. The PLC will have built-in snubbers to accommodate that but they're typically not designed to handle solenoids only smaller relay coils. You should consider using a second relay or much much better a two pole relay and just use one set of contacts for the PLC.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[NoviceInstrum]

Hi Keith
File uploaded

 

[itsmoked]

Hi Novice.

That will work just fine. For some reason I thought you where talking 120/240VAC not DC where a freewheeling diode directly across the coil does a great job of dumping off the spike.

Is that really -24V??? or 0V?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

Was wondering the same. I bet a nickel on 0 V. Maybe even a grand.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[itsmoked]

Gunnar you're turning into a chronic gambler!

You need more shocking-shrimp jobs.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

With a boring life like mine - I can't help seeking excitement whenever possible.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[NoviceInstrum]

Thanks Guys
It is 0V