Hi All -
Looking for options for monitoring the output of a generator ... It puts out standard 240V with a center neutral for two legs of 120V. Would like to track both 120V legs (to monitor for load imbalances) and current draw on each leg, up to 78A (nominal 30A but burstable to 78A).
Also want it to be safe, and simple. This would be monitored by an AVR for display and logging.
Analog ADE7753 looks like it would do the trick. It would also do a whole lot of other tricks, lots more than needed for simple voltage and current monitoring. Not too expensive at around $6 I suppose.
It's a direct-to-120V connection for the voltage measurement, and uses a current-transformer for the current. Or a di/dt measuring device - a Hall-effect sensor ? The ADE7753 would do it all, and the AVR could simply read a pair of registers to get the voltage and current levels. I'll have to read the datasheet more carefully, there's a lot there.
Could use a Maxim MAX4081 for current measurement which would also use a CT, or a Sentron CSA-1VG which would use itself as the sensor. The CSA-1VG gets clamped directly over the main cable to be measured. Seems way cool, but needs a couple of extra boards for the chip, caps, connector etc.
This would mean doing voltage dividers to the 120V lines and manually doing the math to calculate RMS.
Surely someone else out there has done something similar. What did you use to measure 120V and current ?