What is as Safety relay and what makes it safe?

[Another Baker in Va]

What is as Safety relay and what makes it safe?

 

[padees]

They usually have Red colors on them. That's what makes them safe. Just put one in. It will be safe.

 

[bkottaras]

Look up Pilz, they have some pretty good docs on their web site, may help.

 

[cardosocea]

Built in diagnostics, testing of them and engineered to fail in known and safe ways.

 

[Another Baker in Va]

Thanks for the answers, some are just platitudes though.

 

[tarik1978]

Have a look at this link

What is Safety Relay?

Hello everyone. I am Rose. Today I will introduce safety relay to you. The so-called "safety relay" is a combination of numerous relays and circuits that complement each other's abnormal defects in order to create accurate and low malfunction relay complete performance, with the lower the error...

www.utmel.com

 

[jaden]

Safety relays rely on redundancy. Two simultaneous inputs, two outputs, and monitoring to ensure the outputs do go off when commanded to do so.

 

[parky]

They also have positive guided relays so there is little chance of welding in, double checking circuitry for example if one of the relays welds closed it will not let you reset it, many have dual channels, so again if one channel does not de-energise again you cannot reset the system, often there is a facility where you monitor a N/C contact off motor contacts, if one welds in the system again will not let you reset it.

 

[lfe]

Ensure that the machine stops when an emergency button is pressed, or an emergency cable is activated, or a safety cage door is opened.

In fact, in many cases I did not use a safety relay since it can also be done with two contactors approved for that function.

 

[Mr_3D_Print]

They usually have Red colors on them. That's what makes them safe. Just put one in. It will be safe.

I got a yellow one. That's like a warning level right ?

 

[Another Baker in Va]

So safety relays are just a joke and not needed I take it.

 

[ASF]

Your approach is very different to the "other" baker in virginia that hangs around here. His approach tends to get a lot more helpful answers than yours has gathered so far, for what it's worth.

 

[Another Baker in Va]

Well, there was a few of reply's that kind of joked at the question. Maybe I should have asked why is a safety relay important and do I really need one? And what is there importance?

 

[robertmee]

Safety Relays offer safety through redundancy, checkbacks, failure detection, construction methods to reduce welded contacts, and increased reliability for increased MTBF. All of these factors increase the SiL/Category rating of a single safety relay and permits a higher SIL/Category achievement levels for an overall system. I can assure you, they aren't a joke. As an integrator and owner of a company, I take safety seriously due to liability concerns as well as insuring safety of personal and equipment. Any safety system is as weak as the weakest link. You can buy the most expensive safety relay, but if poorly or wrongly implemented is no safer than a standard relay.

 

[ASF]

Well, there was a few of reply's that kind of joked at the question. Maybe I should have asked why is a safety relay important and do I really need one? And what is there importance?

My point was that when the "other" baker asks a question, they provide relevant context and background information, state what they know and don't know already, and then ask a specific question.

An eight word question with zero context that looks like it has been pulled straight from a school assignment is better typed into google than on here if you want help for free. If you want better answers, ask better questions.