Controls.Fail

Putting up a placeholder for a review of these dirty cheap power meters. To be clear, doubt any of these are UL listed and I wouldn't think about using them on a commercial site. These are for my personal use and one of my requirements was a protocol I can pull into my test bench. So communicating, modbus, bacnet, etc and lowest cost.

Just to keep the excitement level within my tolerance level...

Only looking at units that use external current transformers. Nothing that has internal current shuts, aka 100% of the circuit under measure runs through the device.
I added inline 0.5A HRC fuses on the voltage feeds which are tapped off 15A breakers.

Starting with the most feature rich and working down.

PAC5000
https://www.aliexpress.us/item/3256804494752431.html
Paired it with my own split core CTs. Those ran me ~$17 on amazon.

Biggest hassle up front, it came with no manuals. No register list was online anywhere I could find, so rather pointless. The seller did hand them over after a few messages. EM115-MOD
Only works on a single phase or 2W split phase circuit, but did include 100A CT
https://www.ebay.com/itm/323202319151

Getting the manual was a bit easier. Then I found what I expect is about the cheapest that meets the requirements I had.

PZEM-016
All over ebay for ~$15/ea with 100A CT So far all three seem to work as advertised, readings line up with my Fluke DMMs. To early to really have a solid thought on them, but I got a wad of EM115s & PZEMs installed and a PCA5000 on the main service. Will share screenshots of the setup in Tridium to suck each in soon and further thoughts once they have been in for a few months.

Niagara device setup under the modbus driver.

Note the byte order and use preset multiple register settings between them. Some do not support the modbus function codes for multi register read/write.
The PZEM-016 only supports 9600-8-1-n.

PAC5000
EM115-MOD
PZEM-016
Point setup for each.
They all seem to work fine for my needs. The PAC5000 lines up with the utility read as far as I can tell. Get get the dates from the utility, but taking first and last readings on the dates they give its to a few kwh.

Had a short power loss yesterday and some of the PZEM-016 meters I have went out for an extended lunch.

Have ~20 of them now. 3-4 stopped responding. 24hrs later, most of those came back on their own. Seen this before when power down installing additional units. Something is a bit flaky with them restarting. So far, haven't seen a failure. Haven't had the time to troubleshoot in detail. Don't really expect top quality in a ~$15 meter either. When I get some time will dive into this deeper. Gaps in my data is annoying.