I have a customer that wants to install permanent power monitoring on their data center feeder...
They want to be able to record any problems with the utility feed.
We have a few dozen fixed meters that have been installed since 2005 - all EPM/GE multilin - GE purchased EPM a few years ago. We have GE
5300/5350 series meters and
9650 meters. The 9650 series has a waveform capture feature - whenever the waveforms go outside preset boundaries it will perform a high speed capture and show you all three phase voltages and all three currents. Ours are set up for 16 or 32 samples/cycle and record about 8 cycles - 1-2 cycles before the triggering event, the rest after. The length of capture and conditions that will trigger a capture are configurable.
All of the basic metering functions are available: phase and average amps, phase and average voltage, power factor, power, and demand. Harmonics metering is optional.
The 5300 meter isn't as easy to use, plus it doesn't have the waveform capture. I'm not sure if your client is interested in waveform capture, but if you're trying to track utility problems it's the best way to go.
A single EPM9650 meter with display runs maybe $4200. Installation is fairly simple - mount the brick, connect CTs, PTs, control power, and run a cable to the display. They are available with an ethernet port so you can install the free software somewhere on a networked computer to view the captured waveforms and live or logged metering data.
I haven't looked in detail at Square D units. My recollection is that they were similar to the GE products on the low end, but that GE had more features and higher accuracy on the higher end models. The 9650 that I recommend has utility class accuracy, which is important if you're using it as a check on the utility.
What is the main overcurrent protection? If the 1200A main is a power circuit breaker in switchgear there may be an electronic trip unit available for the breaker that would get you some basic metering without having to modify CT nad PT circuits.
