E-stop monitoring relay reset.

[JesperMP]

the only thing to be careful with is remote reset of light curtains
if you reset these out of site is is possible to liven up a machine with someone inside the machine area

That does not sound as an application suitable for a light-curtain.
More suited to a trapped-key lock.

 

[OkiePC]

I have one system that uses a PanelView button to reset a safety relay via a PLC relay output. It has the advantage of allowing the PLC to inhibit "short cyclling" of the big safety contactors that supply power to a bunch of drives. This way, once the e-stop occurs, the PLC can dictate that the circuit cannot be reset for a minimum of 30 seconds, which is enough time for these particular drives to power down to a safe level, and be able to clear away the low DC bus faults they all will generate. It also gives incentive to the operators not to abuse the e-stop when they need the regular stop. They know if they use the e-stop, they will be down at least 30 seconds and have to wait.

I did not design it this way, and I have not done this in the past, although I have thought about doing it. My preference would be to wire a PLC contact in series with the hardwired reset button to gain the same advantage.

 

[killerkaz]

Thanks for the discussion everyone. I appriciate all the input!

 

[iant]

That does not sound as an application suitable for a light-curtain.
More suited to a trapped-key lock.

Probably not
But
prdouction minds may think so..
like I said earliey - risk analisys