Safety System Components

I am wiruig a circuit very similar to page 9 in this manual using the 440 DI http://literature.rockwellautomation.com/idc/groups/literature/documents/sg/440r-sg001_-en-p.pdf

I need an indication from each contactor back to the plc though and I am using 700-HPS relays which are only 2 pole double throw.

In a setup like this since there are 2 relays in series breaking the same load and are redundant do they need to be the positive guided red control relays like the 700-HPS or could a standard 700 series relay be used that has 3 poles?

When you say contactor, are you referring to the 700-HPS units?

Even though it's tempting to use a standard relay you'll still need to use a positive guided safety relay. A standard relay can have a welded contact and not indicate that condition. A positive guided relay will not have this problem.

If you need more contacts in a small form factor safety relay, Omron also has a line of small PCB and socket safety relays (G7SA) that come is a wide variety of contact arrangements.