400 Amp Service and EG4 Grid Boss

[HarryN]

If I needed that much power, I would seriously look at having 3 phase brought in if possible.

 

[Chuck2]

If I needed that much power, I would seriously look at having 3 phase brought in if possible.

It's not much power, it's just broken up into parallel runs to the home (200 feet away) and a barn that peaks pretty hard. None of them individually puts much load on a 200A service, but if combined, you would start seeing light flickers and dimming often. Especially if the barn was communicating with the home feeders. Plasma cutting alone takes a good bit of power alone by the time you have all the lights on, decent compressor running and the cutter moving through anything over 1/2".

I intended to run 3 phase, not because of the loading, but to simplify the use of most equipment. My lathe, mill, overhead crane and bandsaw all have VFD's for phase conversion. The overhead crane has a 480 - 240 step down transformer running in reverse, putting 480 split phase up to the runway where a VFD for each function on the crane does the phase conversion at 480. 3 phase would have been easier, but alas, it's not always in your area. We once had to run 3 phase over a mile down a dirt road to an irrigation pump. At this place I will be running it around 1/4 mile soon to a back pasture from another road, accessed across a neighbor's land who also wants use of the irrigation pump station I will put there. But it will still be 1/8 mile or so from the house and barn.

Maxing out a service so that every light in the house flickers each time another HVAC condenser comes on for the rest of the life of the home seems like poor planning to me, vs running each service feeder much lighter and incurring less voltage drop everywhere. The upfront cost is low. It's very expensive to add service capacity later and it's very cheap in the beginning. Finishing a basement, adding a water heater, adding resistive heat, adding a steam humidifier, adding irrigation...... are all easily handled unless you only have a 200A service and all the lights already flicker each time the upstairs HVAC comes on.... the actual voltage available to those motors during starting will dip more and more the farther behind the ball you push that service.

Cost benefit analysis for "over" spec'ing, vs "under" spec'ing the service capacity weighs heavily on the side of getting the capacity higher than required.

 

[Tommytwotone]

My case is similar and I think I have decided to run multiple 18kpv units instead as I cannot see any practical benefit to the Gridboss system in my case. I would still have to install a blade style disconnect as the POCO could care less about the breaker style disconnect in the Gridboss. I will have to swap out all 3 of my 200A breaker style disconnects at my service entrance now, and the same is true if I used the Gridboss. If I were to use multiple inverters per each 200A service, then a gridboss could take the place of a combiner panel for paralleling the units, although a $200 panel vs a $2500+ Gridboss again seems pointless.

The only feature I like is the ability to use the built in bypass transfer for inverter maintenance. If you can mount the unit close enough to any homeruns, then you can utilize the smart ports and that would be another benefit I cannot use. My service entrance is 200 feet from the nearest main panel for the home. I have no plans to have the inverters or batteries or solar inputs any closer than that to the home anyway, so the smart ports are useless. For the inverter bypass I will install a manual transfer switch to each inverter (still half the cost of a Gridboss) and then repurpose my existing 200A breaker style disconnects to interrupt the feed to the "Load" side of the 18kpv should I need to flip the transfer switch and bypass an inverter for some reason.

I'm thinking one 18kpv per 200A service, one blade style disconnect outdoors in place of the original breaker style disconnects and in the event of a grid outage, have a few select smart breakers over in the home main panel drop out the dryer or ovens or one water heater, so on and so forth as needed, should the usage stack up by others in the house to avoid the need for paralleling inverters to handle worst case peak events WHILE the grid is down and unable to provide that short-term peak loading.

I kept the 200amp breaker style disconnect on the line side of the fused (I found fused to be less expensive) knife blade disconnects. Just easier to change fuses and I would not need a POCO disconnect to work on anything to the load side of the breaker 200amp disconnect.

Just an option swapping the placement of the knife and breaker disconnects and it would save you that POCO disconnect. Assuming your POCO would be ok with it as mine is. They actually preferred it the way we have it.

 

[Tommytwotone]

Thank you for the reply. Sorry for not specifying but my question is regarding your dual-GridBOSS setup. If there are 2 GridBOSSes, 6 FlexBOSSes, and lets say 8 batteries for the sake of argument; all batteries are wired to a common bus bar, so both GridBOSS systems share the same bank - how does closed loop battery communication work? If I understand correctly the GridBOSS systems don't communicate with each other, so which inverters are able to talk to which batteries? Thank you

I believe I read that you would have one master inverter even with multiple Grid boss but I would triple check that with EG4. If my memory, and the article, are correct you would have one master inverter which would go to the master (0) and then you would have all the other batteries communicate with the master battery. Again, triple check that.

 

[Chuck2]

I kept the 200amp breaker style disconnect on the line side of the fused (I found fused to be less expensive) knife blade disconnects. Just easier to change fuses and I would not need a POCO disconnect to work on anything to the load side of the breaker 200amp disconnect.

Just an option swapping the placement of the knife and breaker disconnects and it would save you that POCO disconnect. Assuming your POCO would be ok with it as mine is. They actually preferred it the way we have it.

I agree, I just don't have the real estate. I am already expanding the 4x8 backer I started with a couple feet just to allow the 3, blade style disconnects to fit. I can't manage 6, 200A disconnects right at the service entrance where the POCO wants it, so the breaker disconnects have to vacate for the 3, blade style units.

I will either reuse the narrower breaker disconnects as a maintenance bypass disconnect or shelve them if the maintenance bypass built into the gridboss keeps growing in appeal, while the Flexboss appears to have dropped in price some? That keeps lowering the threshold between an 18kpv plus MTS vs Gridboss plus Flexboss......

 

[Kazoo]

I believe I read that you would have one master inverter even with multiple Grid boss but I would triple check that with EG4. If my memory, and the article, are correct you would have one master inverter which would go to the master (0) and then you would have all the other batteries communicate with the master battery. Again, triple check that.

That's not my assumption on how it'd work, since one set of 3 inverters would have a different load than the other 3, but yeah I'm not sure. Hoping @EG4TechSolutionsTeam replies again