I am having a heck of a time trying to figure out a way to make two ET112s work together, and display information, in a split phase configuration. This is somewhat necessary as we have boats that have 2 separate 30amp 125v marine shore inlets.
I have found a basic workaround to at least have the total AC loads displayed by making one Grid and second one Generator, but they are not displayed together on the panel, only the total is used.
This is manageable, but I am a bit confused of why the Cerbo can’t determine that the two ET112s are separate lines on the same system and enable split-phase configuration. It seems a very basic change in settings on the Cerbo side, which would enable a world of opportunity.
As a Marine Electrician and Electronics Installer, we run across a ton of people who would like an easy way to get the data about their vessel but not have to spend a ton of money right now. Installing a Cerbo is such an easy way to introduce them to the Victron product line and then slowly bring them into the fold with batteries, inverters, and other products. Sadly, cost is always an issue and most of my clients are gunshy on spending $20K on an entire electrical system overhaul. Getting the units like ET112 to work in split phase environment would give them the ability to see their shore power or generator load while also not having to spend a ton of money. Adding Smart Shunts would then allow for battery status and load management. This would get them used to the available information, and then when the time comes they will buy the Victron Inverter and LiFePO4 batteries that will easily fit into the system.
One should be able to use TWO ET112 monitors to combine as split phase. It’s a simple change in Cerbo code that would enable this as the data is clearly there. SignalK displays the information for both meters, and all Cerbo has to do is add them up and tag them both as shore power inputs.
This is not rocket science. In fact, using a three phase meter for split-phase metering is the more complicated and difficult piece.
VenusOS is source-available, most of it is even open-source. Feel free to make the simple change.
Using a single phase meter to monitor a single phase source, and using a three phase meter to monitor single, two and three phase sources, makes more sense
But the three phase unit doesn’t monitor a split-phase system, it’s in beta still, which means I can’t install it on a customer boat. And it still doesn’t display accurately on the Cerbo Screen. In fact, there are extremely few products from Victron that deal with split-phase properly.
Also, I spend my time working on customer boats, trying to keep them bunning and afloat. While I do poses coding skills, taking the time to do something that should already be a part of a product feature set seems a bit outlandish, don’t you think?
Using two ET112s should be exactly the same as VM-3P75CT. In fact, there are cases where the VM-3P75CT would not be possible as some split phase boats have split panels and their locations are 10-15 feet apart, so using two ET112s would be the ONLY option.
Theres lots of things that people added, like GUI mods, NodeRed extensions and many other things. Chances are that someone already had that issue, and figured out a solution, maybe by using NodeRed for example.
I dont quite understand what you mean by split panel. Do you mean that theres a fuse panel fed by one phase, while somewhere else on the boat is a panel thats being fed by the second phase? Even if thats how its done, both phases would be coming from the same shore connection, no? So you could monitor the shore power using a three phase meter before splitting it, one phase here and the other going there
If you come across anything that might assist, please let me know. So far I haven’t come across anything. NodeRed wouldn’t really be the path to a solution though.
I guess you’re not really familiar with boats. Most boats over 38ft in the late 80s to late 2000s came with 2x30amp 125 plugs. Generally, they would be close together and would be feeding into the same panel but feed different systems. About 60% of the boats were configured somewhat rationally, the remaining 40% would actually be a mish mash. Some have plugs in the front and the back, with 2 separate panels each feeding different systems. The back feeds the salon and galley with battery chargers, the front feeds the staterooms. There are actually boats with 1x30Amp 125v and 1x50amp 250v plug, which even further complicates things because it splits the panel into 3 separate systems but the waves are not at 120degrees off, so it’s not 3 phase.
Finally, there are newer boats, like Fleming 58, that have 2x50amp 250v inlets, but they are at opposite ends of the boat and you can use them individually, or you can use them together to feed power to the boat.
So overall, you NEED to be able to use different sensors individually, and then configure them in Cerbo to accurately represent the configuration, whatever that is. The data is being received by the system, it just needs to be displayed on the screen and in VRM
Im not too familiar with boats. thats correct. I worked on some the occasional time, but solely european boats, or ships since they were all gravel haulers or other merchant stuff, and most for a few days to repair some things
Thanks for the explanation. Makes me like my three phase even more.
Sorry if this is getting too off-topic, but why not keep it two separate systems? I mean, a cerbo is designed to be used in one system, it has a grid feed-in, maybe a generator feed-in, a battery, maybe some PV, and one or two AC outs. Thats what its designed to do, everything else is pushing the envelope. Dont get me wrong, i know you are trying to fit a good system into tight budgets. But it just sounds like you would need two entirely separate victron systems when dealing with two separate ACs.
I dont know, ill keep an eye in here of news, im interested in this as well, but i cant bring any more value to this sadly, cheers
Couple of things, I believe that Cerbo has significantly more capability than you might think. It has the chance of being a whole vessel management system with SignalK and NodeRed. The fact that it has ability to control remote relays, measure tank levels, and accept input from digital sensors is the living proof that this thing is destined for greater things.
That being said, having two units complicates things in many ways. It adds complexity where it doesn’t need to be.
This is a simple display issue. If someone like @kwindrem could figure out a way to at least display it properly on the screen, it would go a long way towards making this work.
