E stops

ganutenator

Lifetime Supporting Member
Join Date
May 2002
Location
kansas
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We use a force guided idec relay for our e stop circuit.
Having problems recently getting the product.
Are force guided relays really necessary?
I've never seen a mA ckt weld contacts.
 
I am sure you can get a force guided relay from another manufacturer as a substitute? You would need to replace with the same type to maintain the machine's safety function. So yes, you would need to replace with a force guided relay.
 
Allen Bradley 700-HPS2Z24 if that's something like you use? My supplier has 100+ in stock
/Tim
 
If you use only 1 channel of the relay, it doesn't matter. PG relays mean the n/o and n/c can't be true at the same time.

If you're only using say the n/o, it makes no odds.
 
If you use only 1 channel of the relay, it doesn't matter. PG relays mean the n/o and n/c can't be true at the same time.

If you're only using say the n/o, it makes no odds.
For E-stops, which this thread is about, the minimum PLr is "c", so that means you need multiple contacts for either switching through the activation and/or for the diagnostics channel.

I am also certain that "force guided" means that there is less probability of a contact sticking, so even for a single channel with no feedback it will be safer.
edit: Thinking about it, in that case it is the ONLY safety !

And, the codes require force guided contacts, why are we even discussing this ??
 
Last edited:
Sidenote. If you have trouble sourcing relays with force guided contacts, then use a plain simple contactor instead. These (almost) always have force guided contacts.
I have only experienced an AB contactor where it says in the specs that its contacts are not force guided. Any other contactor also mini-contactors I have ever encountered have force guided contacts. And you usually get huge discounts on standard devices such as contactors so it is not more expensive.
So, we only use contactors in safety circuits.
 

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