3 phase 480v across the line starter with 24v coil. person that built this panel took the 24 - straight to the coil instead of thru the overload relay, and instead used the overload relay contacts to send an input to the plc if an overload occurs. I do not like this method but not sure if it is an acceptable approach. far as I am concerned it is a no-no but hate to raise a stink for nothing. let me hear your opinions. Thanks

Does the relay have a N/c and N/o contact?
95-96 wired to the coil
97-98 wired for indication to PLC with logic change.

Or maybe wire thru the overload to the coil and tap off to the PLC input without logic change?

If it's that simple then why not?

yeah has both n.o. and n.c. contacts dont know why they done it the cheesey way.

Sounds correct to me. 24Vdc signal direct to starter. Overload Relay does it's job and if tripped, power to motor is removed and PLC gets signal that O/L is tripped.

I motor starter boxes with push button on / off buttons only typical to wir O/L trip contacts in series with coil.

Bud

I can't remember any specific issues about this in terms of safety, but I'll bet your insurance company would have a fit over this since it means the PLC could effectively ignore the signal and let the place burn down.

The major issue though is that in the event that an overload relay trips, you MUST investigate the reason why it tripped BEFORE resetting it. The reset action has to involve manual operator intervention in almost every case. Sticking it in the PLC where someone can just press the start button and try again is a no-no. That's why "auto restart" is usually (but not always) not allowed even though most overload relays have that feature.

If I provide operator feedback, I will typically do it via an auxiliary contact on the start coil itself, not from the overload relay. The reason is that then I can detect a larger variety of faults at the PLC, and correctly reset the PLC side of things so that it doesn't instantly try to restart on a fault condition.

Late entry, but this is essentially correct.
In order for you to be able to use the PLC and OLR in that manner, the PLC would need to be UL listed as an OL relay itself, including the necessary fail safe protocols, with the actual field OL Relay acting only as a sensor. No PLC that I know of is so listed, it makes no sense to do it that way. As others have said, hopefully you wired the OLR to the coil and wired the OL Aux to the PLC separately for status indication.

This is incorrect, first you need to protec the motor and second you need to provide a mean for the starter to shut down the motor if an overload occur. What He did is against the NEC. If the overload has more than one NC He could have used one NC to protec the starter coil and one NO to control the PLC which is no a good practice. The correct thing to do is to trigger the PLC with an NO auxiliary contact from the starter and to protec the starter with a NC contact from the overload.