Safety Rated vs NonSafety Rated Components
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Hi, my name is Jeff Rogers. Often times I’m asked what the difference is between safety rated and non-safety rated components. There is a really big difference. I often walk into plants and see components all over the place that people are using such as through beam sensors for perimeter guarding that are not safety rated. To not use safety rated components can mean the difference between a law suit, potential injury or death and just a properly functioning safety system. A few things that I wanted to discuss today are a few of the differences between the two, how they can resemble each other and still be completely different, and what is going to make one a better choice than the other.
If you are going to use a component for a safety circuit, when you are thinking safety components that needs to ring in your mind reliability, redundancy, and fail safe. Those are the three main things that should come to mind when thinking about that. Like the example I stated earlier a through beam sensor can be used as a perimeter guard, but if it is not hooked up to a safety monitoring relay for instance if there is a problem with that sensor the circuit may not know. Your machine may keep operating even if someone walks through and someone could potentially get hurt by that piece of equipment. There are also things out there such as programmable safety controllers that exist, as well as just discrete components such as interlocks or safety rope pulls that have certain types of internal components that are used so that it’s reliable, it’s called control reliability. That’s the one thing you always want to make sure. You’ll hear things such as force guided contacts that are important in these types of components it basically means if a contact welds shut it can then be forced open so that the circuit can be broken. Most safety circuits are closed circuits, so in the event of power loss the circuit is broken and everything fails to a stop. If you look at this interlock you can see this is a tongue and groove type interlock. The internals of it you can see if I push on the plunger in here you can see that red piece moves the contacts up and down. They are all mechanically linked together. That is one example. Another thing is this symbol right here which is a circle with an arrow inside of it stands for forced guided contact. That is important to use when picking out safety components.
The things that you really want to remember are the safety regulated components are more expensive, they always will be because of the redundancy that is built in. When it could mean serious injury or death don’t go cheap because if you do it could cost you more in the long run. If you are not sure, there are a lot of grey areas, ask somebody. Don’t leave it to chance. There are professionals out there. You could go to our website at innovative-idm.com and go to our knowledge center. We have white pages that exist and we could come out on site and help you solve those things. We’re not the safety police. We’re not going to report you to OSHA, but we want to help you make better decisions when dealing with safety circuits and know that there is a difference. Using non safety rated components in a safety circuit is never okay. That is all I have for you today. After all we are the home of the Legendary Customer Experience.