# Best safety relay?



## piperunner (Aug 22, 2009)

MDShunk said:


> I have a little job replacing guard switches and the safety relay on an ice cream filler with 8 guard doors. Who makes the most user-friendly safety relay? When I got out of factory work, purpose-built safety relays were just coming on the scene, and if they wouldn't close, it required you to break out a meter to find out which door switch wasn't working right. With multiple contacts in each door switch, this was a pain. Is there a safety relay on the market yet that will illuminate a light or read out something on a front panel display that tells you which guard switch is open?



Well we know theres always a company out there but i think a program micro controller with zones and contacts would be your best .

A adriss for each door and a indication all in one package i think a company called SDS makes boards for anything .

One cable does it all !


Unless you want to build you own board .


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## Jlarson (Jun 28, 2009)

I'd probably go with IDEC's FS1 PLC and some of their interlock switches. Or maybe an AB or Phoenix Contact saftey controller, depends on which supplier answers the RFQ first for me really.


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## Frank Mc (Nov 7, 2010)

Most safety relays i have used are 2 channel and have led indication of which channel is tripped...I f you need to know which guard is open then use guard switches which have 2 n/c contacts and one n/o and connect the n/o to a plc input...That,s common practice on gear i have worked on....There is other gear that uses a bus connected to safety switches which have led,s...One that i recall were called adam + eve switches i,m sure there are others....
http://www.sensorsafe.com.au/safetyswitches/eden.htm

HTH

Frank


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## Sawdust454 (Sep 26, 2008)

I like the safety controller from Banner,
http://www.bannerengineering.com/en...and-Controllers/442/SC22-3-Safety-Controller/
Coupled with a interface module,
http://www.bannerengineering.com/en...Modules-and-Controllers/35/Interface-Modules/
The controller is easily configurable.


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## JRaef (Mar 23, 2009)

Depending on the Safety Category you are trying to achieve, you may not actually be allowed to wire multiple guard switches in series, each one might need to have it's own channel. But if you are only after Category 1 and maybe 2 under certain uses, then it can be done, but that's what you give up; the ability to troubleshoot it easily. Many of the Safety Relay mfrs are now offerring "modular" safety controllers that allow you to stack on input modules as necessary so you can keep them all separate.

Many mfrs also offer "ASi-Safe" systems. ASi (Automation Sensor Interface) is a 2 wire communication system between a host controller such as a micro PLC or even a "smart relay" and safety sensor devices, each with it's own unique address. With the right controller, you can even have a display that will tell you immediately which sensor tripped and when (as in first, second, third etc.). An ASi-Safe Interface module satisfies the Safety Category requirements, right up to Cat 4, but communicates to the host controller for operation and troubleshooting data.

Link


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## sagnew (Mar 24, 2011)

I've mostly used Pilz. 

For multiple doors I have hooked them up in series. This is the cheapest but a paint to troubleshoot. 

I used a schmersal relay that had 12 channels on it. Each channel had a led readout:thumbup:. I used two channels per door switch. 

For safety circuit I would stay away from using a traditional PLC. 

If you have the money, I would go with the modular safety relay or a safety PLC. You can program it to do what you want.


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