Protecting ML1500 Inputs

I am working with a ML1500, by requirement, and am monitoring 4 different systems at the same time. I was wondering how the experienced guys here would go about protecting the ML and making sure that a surge on one system would not feed into the others.

All monitored points will be 120VAC push buttons and torque switches.

I was initially thinking fuses but the ML wouldn't really draw anything unless it burnt up, would it?

You could use optocouplers on all the inputs to provide isolation. Readily available from many manufacturers. A quick Google search found these...

http://www.clrwtr.com/PDF/Weidmuller/Weidmuller-Optocouplers.pdf



-Eric

PLC Inputs have some protection built into them. There are a couple of things you could do to add to that. Make sure all the different System Neutrals are tied together, and use 120VAC Movs on the Inputs.

Stu.....