Does anyone have experience using modbus with high end breaker trip units? Like Eaton PXR25 or SQD MicroLogic 6.0P. We're looking only for power data

tress · ‎2024-04-28

Does anyone have experience using modbus with high end breaker trip units? Like Eaton PXR25 or SQD MicroLogic 6.0P. We're looking only for power data from the breaker, not remote control of the trip unit if that matters.

The trip units have native modbus RTU and there are external comms modules available (modbus to module, ethernet out), but looks like they're marketed more for a separate power metering network. Also only seeing Modbus TCP, not EIP.

We use newer compactlogix 5380 (sometimes 5570/80) so it looks doable to talk Modbus with a serial module at PLC (or remote IO). Looks cheaper to go modbus all the way, but I have 0 experience with serial in Logix.

If we go this route with fancy breakers, I see as options

modbus RTU from PLC directly to breakers

buy the Eaton/SQD comms modules and then gateways to EIP

maybe separate modbus gateway/server/master/idk? to eliminate the breaker comms modules

I've tried to avoid serial (it's 2022...) but I'm thinking that the learning curve would be similarly long for any option that I'm looking at here.

Some background We do LV power systems for industrial furnaces & such, for example maybe 12 zones 50V 2kA. Customers often spec that TX secondary power data is to come from our PLC for their SCADA. We've done this with CTs & PTs to power meters or sig conditioners. But when customer wants secondary disconnects, it seems like a good fit to get a fancy trip unit that can read all the power data that they want, without extra components. We don't actually need the overload protection from the breaker, would just be using it as a disconnect switch.

So for my questions... Has anyone here successfully done PLC comms directly to breaker with RTU for power data? Or with the external comms modules? Would I be better off with 5069-SERIAL or remote IO? We've used a little bit of WAGO 750 and Phoenix inline, but no serial comms.

Thanks!

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