DIYrich
Solar Wizard
Unless you have load between the Meter and the Gridboss.
EG4 GridBOSS Deep Dive
- Thread starter FilterGuy
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DIYrich
Solar Wizard
Production meter between Meter and Gridboss will miss any self-consumption. As shown in the greyed box, PM goes between the EG4 Hybrid Inverter(s) and the Gridboss. May need:
EG4 Inverters -> Busbar 1 -> Production Meter -> Busbar 2 -> Gridboss Inverter Inputs
DIYrich
Solar Wizard
Need external bypass if you ever need to service the gridboss and don't want to take down power to the house. Not worried about "functionality", I'm worried about servicing it.
Yes, corrected the post.
I don't know why either, but you never know unless they say it is ok.
timselectric
If I can do it, you can do it.
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That's not how it should be setup. But I guess there might be some weird case for it. I don't know what that would be, or why.
I haven't seen it posted on any of the questions that I've seen.
Would the GridBoss work with 2 different EG4 hybrid inverters or do they have to be the same? For example, I have an 18kPV right now and want to add the GridBoss along with the FlexBoss21 (to save $$ over purchasing a 2nd 18kPV). Would they both be able to work together with the GridBoss?
Would the GridBoss work with 2 different EG4 hybrid inverters or do they have to be the same? For example, I have an 18kPV right now and want to add the GridBoss along with the FlexBoss21 (to save $$ over purchasing a 2nd 18kPV). Would they both be able to work together with the GridBoss?
1201
Solar Wizard
Retrofit.
For example my inverter is in a shed 100 ft from my meter, and my main panel is another 70 odd ft from the shed. To use the grid boss i would have to replace over 180ft of buried wire with bigger wire, and replace the subpanel at the shed with a 200a one.
chill633
Solar Enthusiast
This whole thread is awesome, but this diagram is the icing on the cake! It answers almost all of the remaining questions I had.
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timselectric
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Yes they will.
timselectric
If I can do it, you can do it.
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Because, that's how they have always done it. (Change is hard)
They haven't caught up with hybrid systems yet.
Before bidirectional metering was available. Two meters was the only way to do grid-tied metering.
Ug... so they essentially add and subtract to get what you actually owe? Seems pretty invasive to me.
Thankfully, I was lucky with my install, I was able to put the inverter easily between my meter and my main. Something like the gridboss seems like it would be very nice! I'll be interesting to see how some of those switching capabilities work in the real world. They're trying to get pretty low switching times for the relays.
timselectric
If I can do it, you can do it.
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This is the reason for the gridboss. It goes at the meter, and everything else can be remote mounted.
But as long as you put the gridboss between the meter and main panel, it could be located at the shed, with the inverter.
1201
Solar Wizard
I wouldn't put electronic equipment outside in Texas, but that's just me, not saying it wouldn't survive.
but, walk me through what my "at-the-meter" retrofit would look like.
my main panel from the house( non backup) would connect to the non backup output of the grid boss. wire is already there so not a very big deal
the inverter in the shed would also connect to grid boss at the meter. wire is also already there so no big deal.
but then would I have to run a new another 100ft wire from the grid boss backup output back to the subpanel in the shed?
timselectric
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That's an odd one. But I would think that you could wire the shed subpanel between the gridboss and inverter. This would avoid a second run of wiring.
But I don't know if it would confuse the gridboss with missing power disappearing from what it thinks should be coming back from the inverter.
I don't know where that production information is pulled from. (The inverter or the gridboss)
Edit: I would probably need a rough sketch of your system, to know exactly how you are setup.
1201
Solar Wizard
.
I guarantee someone is going to try that and we will all find out what happened
hmm that's an interesting possibility. so the 18kpv is feeding the grid boss through the backup output instead of the hybrid input?
I guarantee someone is going to try that and we will all find out what happened
James Showalter
CEO, EG4 Electronics, Signature Solar founder
yes! this mix and maatch has succeed in testing and is pending release
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
He folks, EG4 just posted their one-line drawings for GridBOSS:
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
BTW: EG4 is starting to do these drawings for all of the inverters. You can find them under the downloads part of the web page for each product. (I don't know if all of the inverters have them yet but my understanding is that they will).
These are valuable resources for DIYers and Installers alike.
Maybe a dumb question...
If you have 2 FlexBoss21 units but one has 2 batteries and the other has 3, will we still use both inverters to charge all batteries?
Or does inverter 1 charge the 2 batteries and inverter 2 charge the connected 3 batteries? Seems like we cannot just connect all 5 together in parallel while having the bank of 5 connected to both inverters.
Please don't hit me too hard, I'm a noob!
If you have 2 FlexBoss21 units but one has 2 batteries and the other has 3, will we still use both inverters to charge all batteries?
Or does inverter 1 charge the 2 batteries and inverter 2 charge the connected 3 batteries? Seems like we cannot just connect all 5 together in parallel while having the bank of 5 connected to both inverters.
Please don't hit me too hard, I'm a noob!
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
What you show is a split battery bank. (There is a setting to enable this). Each inverter will charge whatever batteries are attached to it.
My understanding is that you can have different-sized banks between the inverters (with the parallel communications cable), and the inverters will adjust which inverter is supplying the most current in order to keep the SOC balanced between the banks. Pretty slick!
Ahh found another doc on this:
CONNECTION OVERVIEW &PARALLELING GUIDE - Page 7
4.1 BATTERY CABLE CONNECTIONS
The following battery cable connection diagrams are examples using the internal busbars to parallel the batteries together and attach the inverter(s) to the batteries. When relying on the internal busbars, up to 3 batteries are supported in parallel when connected to a single inverter, 4 batteries in parallel when connected to 2 inverters, or up to 5 batteries in parallel when connected to 3 inverters.
So adding a 5th would require the busbars etc.
Trying to figure out ways to keep from adding wall art to the house while trying to generate enough yearly solar production. If I limit solar interconnect to 10kw I can stay away from this Combiner Panel / PV Meter / Disconnect / Combiner Panel *cough BS cough*, adding another battery would have helped but seems to create more problems.
I'm hopeful I can get away with this PV Meter before the Grid location... Sadly it's not showing on the interconnect diagrams...
CONNECTION OVERVIEW &PARALLELING GUIDE - Page 7
4.1 BATTERY CABLE CONNECTIONS
The following battery cable connection diagrams are examples using the internal busbars to parallel the batteries together and attach the inverter(s) to the batteries. When relying on the internal busbars, up to 3 batteries are supported in parallel when connected to a single inverter, 4 batteries in parallel when connected to 2 inverters, or up to 5 batteries in parallel when connected to 3 inverters.
So adding a 5th would require the busbars etc.
Trying to figure out ways to keep from adding wall art to the house while trying to generate enough yearly solar production. If I limit solar interconnect to 10kw I can stay away from this Combiner Panel / PV Meter / Disconnect / Combiner Panel *cough BS cough*, adding another battery would have helped but seems to create more problems.
I'm hopeful I can get away with this PV Meter before the Grid location... Sadly it's not showing on the interconnect diagrams...
1201
Solar Wizard
question for @FilterGuy
Is there an easy way to remove the grid boss from service and still have power from the inverters?
Is there an easy way to remove the grid boss from service and still have power from the inverters?
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
If I understand your question correctly.... not really. The GridBOSS is the central part of an ESS System and as such is the central wiring point of the AC part of the system.
It is possible to turn on the interlocked bypass relay and leave the inverters on, but if the grid goes down, the disconnect relay will open, and the backed-up loads port will no longer be powered.
spiker611
New Member
The 18kPV diagram[1] and gridboss diagram[2] have different values for required breakers:
Says "For flexboss21 ... breaker to the gridboss needs to be 80 amps". And the table for breaker values goes up to 80 amps for the inverters.
"EG4 hybrid inverter breakers: FlexBOSS21: 90A" and the breaker value table is different.
[1] https://eg4electronics.com/wp-content/uploads/2024/09/EG4-18kPV-System-Wiring-Diagrams.pdf
[2] https://eg4electronics.com/wp-content/uploads/2024/11/EG4-GridBOSS-System-Wiring-Diagrams.pdf
Says "For flexboss21 ... breaker to the gridboss needs to be 80 amps". And the table for breaker values goes up to 80 amps for the inverters.
"EG4 hybrid inverter breakers: FlexBOSS21: 90A" and the breaker value table is different.
[1] https://eg4electronics.com/wp-content/uploads/2024/09/EG4-18kPV-System-Wiring-Diagrams.pdf
[2] https://eg4electronics.com/wp-content/uploads/2024/11/EG4-GridBOSS-System-Wiring-Diagrams.pdf
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Good Catch. I'll forward the feedback to the right folks at EG4
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