Signal Surge Protection

[Engineer_UA]

Hi Folks,
Is surge protection recommended for field wiring connected to PLC inputs? For example, I/O originating from field devices located outdoors and routed indoors and connected as inputs to the PLC? The field wiring would be routed in grounded steel conduit, my concern would be for any lightning/transient conditions.
Thanks,
EE

 

[Bit_Bucket_07]

It's an expensive and cumbersome job, but I have done it at highly lightening prone sites.

In the long run, it's less expensive than replacing input modules.

 

[goghie]

My advice is to use interface relays for DI/DO and signal isolators for AI/AO.

 

[TWS]

Since you did not specify the type of I/O.
This should cover most field devices.
https://www.eaton.com/us/en-us/products/backup-power-ups-surge-it-power-distribution/surge-protection.facets$4089882017$2598156606.html.

Quote:" In the long run, it's less expensive than replacing input modules"
As long as you aren't concerned about down time, labor or travel expenses.