Allen Bradley's TRIAC output modules


Thread Starter

David McAnally

Is designing a control circuit such that a voltage from a control circuit that is unrelated to the PLC control logic damage a TRIAC output module? The voltage is the same phase voltage as the power supplied to an Allen Bradley 1791-OA32,
110 volt, TRIAC, output module.

Steve Myres, PE

I don't know the particulars of the AB module, but I did this once a long time ago with a TI545 and didn't experience any problems like
backwards leakage or damage to the output. (By definition the output can block that voltage level, so I'm sure it should be OK.)
Yep, it should work. I have done this several times. One thing to watch out for though, if you have some sort of E-Stop or safety circuit
that kills power to your output modules, you can actually backfeed in through this output and "re-energize" the bus. It's not safe, but it
should not hurt the module. It will also circumvent your fuse protection going to your output module.