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Grid Meter to use for Split Phase 240v - 200A Service?

I'm looking for a grid meter for use with Energy Storage System design. I live in the US, with split-phase 240VAC power, my home has 200A service, phase angle is 180*.


Would the Carlo Gavazzi EM24DINAV53DISX work? I wasn't sure since it's marketed as 230VAC 3-Phase compatible which is not available in the US.

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2 Answers
ee21 avatar image

Got an answer from Carlo Gavazzi support. The EM24 does support Split Phase 240VAC, up to 200A using Current Transformers.

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I am also interested in this question. Did you actually try it?

I'd also ask if ESS accesses the EM24 meter in a manner that results in the total power being read, or if it tries to read the power for each phase and do its own calculations, or something else. Relevant to this:

On this page: https://www.victronenergy.com/live/energy-meters:start?s[]=gavazzi

It says:

In the ET340 - the energy imported and exported is counted at each individual phase and then the Total is provided from the sum of those values.

In the EM24 - the energy imported and exported is counted as a total power, with net differential readings from each phase cancelling each other out.

I'm just guessing that there is no code in ESS specifically for the US split-phase system because it isn't seen in any supported country. So, will it "just work" or are there going to be issues, even if the meter supports it?

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I have not yet, the quote I got from the manufacturer was around 750$ just for the energy meter. I certainly will let you know once I have.

I would also be interested in this solution although the price seems steep for the functionality. Was the $750 retail or are you able to find it cheaper?


Thanks

That was the quote directly from the manufacturer's sales team. And yes, that seemed quite steep indeed, considering the two MultiPlus Compact 2000s I'm using were around $1000 each.


The specific model their sales team confirmed would work with my setup was:

EM24DIN AV5 3D IS X

I was originally concerned because the voltage listed in the specs for this model was misleading (I think it listed something like 230v per phase or something), but that was apparently was a range of acceptable voltages, and the listed value was the "maximum allowed voltage allowed up to" voltage, meaning 120VAC (or split phase 240VAC) would be just fine.


To be honest, at this point in my setup, I have the ESS Assistant working exactly the way I want it to, without the use of an Energy Metering device configured in my Venus GX. I am interested in my whole home's net consumption, but the cost to get that data seems too high at this time, I'd rather spend that money on additional lithium battery modules, but will post here if I ever have extra cash burning a hole in my pocket and do end up buying one.


So today I measure my overall usage through this device: https://iotawatt.com/

At the time I paid $150 for the base station and then spent another $30 or so on some addition CT sensors. From there I graph the data in EMONCMS. I can get a nice view of consumption (GRID & Loads) and production (PV). Biggest thing that is missing for me is Battery Bank SOC / Volts. There are options to grab and graph that data but I have just not got around to buying the addition hardware.

I wonder if there are other CT / meters options that are more economical that are supported by Victron? I did notice that the MultiPlusII leverages a CT clamp I believe similar to what I use for my Iotawatt unit and those can be had for 'cheap'.


I am interested in your overall setup since today I am using a 'cheap' inverter and am looking to upgrade to either Victron or an Outback. Do you have a hybrid setup or completely off grid? I am looking at a hybrid setup to minimize grid usage and avoid selling back. Thanks

I have mostly given up measuring overall net usage, and just taking to inferring based on the data that is available to me/looking at my utility bill. I had an Aeon Labs Home Energy Meter before for about the same price you mentioned, problem with most energy meters besides the Carlos Gavazii ones is they don't read reverse current properly so it became depreciated as soon as I got solar. If you look at the Victron forms, other people have asked the same question and been told no, CG meters are only ones supported besides the Victron branded external CTs.


I have an on-grid connected ESS setup, I use my batteries to offset the energy I use during peak pricing times, to the super-off peak hours. I permit the system to feed in AC back to the grid as well during those hours, as I receive credits that can be used to buy back energy later. What I do to accomplish this is set the Grid Setpoint to -10,000 watts (PV output reaches up to 9,000 watts), and then enable "Limit Inverter Power" so that my battery bank is being discharged at a consistent rate during the on-peak hours; weather that energy goes to my loads, or gets sent back to the grid it really doesn't matter to me. To stop the system from discharging or charging during the "mid-peak" I simply set an option during those hours in "Scheduled Charging", but set the SOC limit low, around 25%, it will charge up to the amount, but not discharge at all during that time. And then during super off-peak, I set it to scheduled charging but with the SOC limit at 100%.


Specifically I have split-phase 240VAC power (Southern California, USA), L1+GND= 120v, L2+GND=120v, L1+L2=240VAC. I have two MultiPlus Compact 24/2000, running in a 180* Split Phase operation mode, with the grid connected on the only AC input. My PV inverter unfortunately is connected in parallel with the grid, NOT on the AC Out of my MultiPlus.. Although the PV inverter is still added to my Venus GX, and is sending the data to VRM. The AC Out of the MultiPlus system goes to a sub-panel which powers my critical loads.

Yes, I'd also love to learn more about any ESS system running in the USA.

AFAIK: Victron has certified only two 120V Multiplus versions to UL 1741 for the US:

https://www.victronenergy.com/upload/documents/Certificate-of-Compliance,-UL-1741-and-CSA-C22.2,-MultiPlus-12-3000-120-50-120V-&-MultiPlus-24-3000-70-50-120V.pdf

Seems like you need that certification for ESS? I'm hoping for 48V Quattros ... someday.

It would be pretty cool if OpenEnergyMonitor could be used instead of proprietary meters from CG. I'm looking into their integration with openEVSE vehicle chargers already. Charging your car when there is PV available isn't so different from what ESS does is it?

Mike, thanks for the link to iotawatt. I've been looking for a more affordable (& accurate) energy meter. Maybe this is it.


Well that's the thing, they really aren't certified yet to my knowledge at least; I didn't even think those two models you referenced were either, maybe I'm wrong though. I contacted Victron support whom informed me from a hardware perspective the current 120VAC line of the MultiPlus's sold in the US should meet all current code requirements, that it was simply a matter of obtaining certification, and then releasing a firmware update.


In the meantime however, and I will preface this by stating the fact that I am not a certified electrician, or Victron equipment installer, or anything in between.. I am an avid DIY-er, and have taken a bit of a gamble I will admit to say the least, by attempting a fully DIY ESS installation, going as far as to use my own homemade 7S lithium battery bank using 18650 cells... This, by current standards here, is not code complaint to my knowledge, however the system is still working beautifully.


Before even attempting a DIY ESS installation, I did at least obtain a "Generating Facility Interconnection Agreement", meaning the utility company was made aware that we planned to install a residential energy storage system that would be selling back energy over the grid mains, something which is actually highly, highly encouraged, and incentivized here in California. Furthermore I looked into anti-islanding, and my PV inverter had not been installed (by a local certified professional) with any additional equipment in this regard, with the exception of the PV inverter's inbuilt protections, which after researching, were on par with the MultiPlus.


The inverters were installed and wired, and configured myself. Having no prior experience with Victron equipment, this was actually a breeze, and I foresee myself being a strict brand loyalist moving forward now, I absolutely love everything about the equipment.


As far as the configuration goes to achieve ESS working in the US, I simply used the "other, not compliant to any local grid code" option, and customized the AC low/high disconnect/reconnect values to be very tight, disconnecting when voltage dropped below 114VAC from 120VAC, or above 125VAC. During my testing of a simulated grid-failure, the MultiPlus's responded in milliseconds when the AC-In was disrupted, severing their connection with the grid, and entering inverter-only operation mode; the voltage across the mains terminals when this occurred dropped to 0V faster than it took me to glance over at my equipment.


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