KWH Meter

[desuhardi]

Hello all,
I want to make kWh record with PC. kWh meter is Merlin Gerin, with 1 impulse of 200ms every 10kWh. Is it possible to connect this pulse to digital input of PLC, like as Mitsubishi FX, Toshiba T1 or others ? Or any other idea how to get kWh data to PC ?
Thank you

 

[John Soltesz]

Sure you can. The impulse is long so it should not be missed. Use the pulse to increment a counter then use that counter value as the number of 10kWh logged. That value would be stored in the PLC and downloaded to a PC via whatever software you choose, like a SCADA or HMI package.
If the meter has communications available then you would do a direct connection to a PC and using appropriate software you would transfer the values. You would need to have the correct drivers and formats to do this.

 

[Greg Dake]

I know this doesn't answer your question, but if you happen to be concerned about motors I know that a lot of VFD's now have KHW meters on them. If it is motors you're looking for KWH and they're on VFD's that show KHW, you could get more granular in your KHW data collection. Your drives would have to also be on a network of some sort to get the data.

I've often wondered how accurate the KWH meters on VFD's are...Perhaps I'll start another thread instead of hijacking this one.

Greg