Allen Bradley GuardMaster- Looking for internal workings of this Safety Relay

[Baker in Virginia]

Good Afternoon ,

We have a number of these Allen Bradley GuardMaster Safety Relays in the plant. We had a problem with a safety circuit this morning. Would you folks have a link to some detailed internal diagrams showing the workings of the internal electronics ? The Rockwell website has a Block Diagram but it does not show much. The model I am working with is MSR 127RP ( 440R-N23134 110 vac Supply) and the MSR 127TP ( 440R-N23132 24 AC/DC ).

Also , these 2 operate the same , just the supply voltage is different , correct ?

Thanks so much,

 

[ASF]

It's been a while, but I *think* that the RP and the TP differ in their reset philosophy - one is automatic reset (i.e. resets as soon as the safety channels are healthy, provided the reset loop is made) and the other is monitored manual reset (i.e. must see safety channels become healthy and THEN the reset input turn on, and then off again).

The manual has some block diagrams of the internal workings, but it depends on how they're wired as they can be configured to work in a few different ways depending on how you connect the wiring. In general, they need to see both safety channels turn on at the same time (or within a certain fixed tolerance), and then the reset loop must be either already made or pulsed on and off to reset, depending on the outputs. When you operate the safety device (e/stop, guard switch...), both safety channels must turn OFF at the same time (or, again, within a fixed tolerance). If they don't, the safety relay will generally fault and will have to be power cycled to make it work again (some of them will work again if you release-press-release the e/stop again, and the inputs all turn on and off correctly again). I believe many of them will also fault and require power cycling if their output channels are detected to not switch on and off correctly, but I've never had one fail in this manner to be sure.

If you need more information, provide some more detail about the fault you experienced, and the symptoms you saw.

 

[Jeev]

As above. The literature on the MSR127 is pretty light, but see if the installation instructions help:

http://literature.rockwellautomation.com/idc/groups/literature/documents/in/440r-in060_-mu-p.pdf

http://www.cedes-sa.com/en/assets/File/produkte/msr127/MSR127RTP_57516_2.pdf

Perhaps we can help if you describe the set-up and the issue you're having?

 

[Baker in Virginia]

Thanks so much .That is good stuff . Have a good evening .