Interlocking logic

[Mbrooke]

When doing electrical interlocks for breakers, MODs, ground switches and other devices would you go with separate auxiliary relays or wire everything into the back of the Electronic Device (421/487E/451 relay) using freeform logic and boolean as interlocking?

What are the pros and cons of each?

 

[cranky108]

For safety reasons, I would use a key or wired type interlock. And not a software interlock.

Too many people out their that can do logic faster than they can think.

 

[Mbrooke]

Interesting perspective! I thought the other way around but you make a really good point.

 

[Electro500kv]

I don't like software interlocks for anything tied to protection. I think it is bad practice and doesn't tie in well to company lock out tag out procedures. How do you tag a software interlock? No one has to physically interpret logic with a lockout relay with a tag or padlock. When people's safety is in mind, make everything as simple as allowable.

 

[Mbrooke]

Never stopped to consider that aspect. Again, thank you!