Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


PLC test setup spike protection

PLC test setup spike protection

PLC test setup spike protection

I am designing a simple test setup with an Crouzet PLC. I am concerned about fusing and voltage spikes or bounce that would damage the PLC or other components, or give false reads on the PLC inputs. I have no control, at this point, over the PLC code. I would like to mimic as close as possible the actual equipment, which consists of the following: Actual inputs are two 2-position joysticks (with center null), PEC outputs, and a series of relay outputs. Actual outputs are just relay inputs. The whole system operates on 24VDC, and the PLC instructions suggest a 1A quick-blowing fuse on the high side of the 24V to be used for both the PLC power and the PLC relay inputs. It also suggests an 1A fuse or circuit breaker for the 24V common. I am using a TDK-Lambda HK150A-24A power supply which output maxes out at 6.5A to run the entire setup. To mimic the actual equipment components, I would like to use toggle switches, and maybe LED lights. Does anyone suggest using pull-up resisors or diodes or some other form of de-bounce or spike nullifier, or should I be safe with just the toggle switches? The PLC inputs and outputs are relays.

RE: PLC test setup spike protection

If you really want to mimic what is in use, use the same type of relays for your inputs ans outputs, look at the protection (if any) in the field and copy it too.

RE: PLC test setup spike protection

Really good suggestion, thank-you.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close