EG4 6500EX 120/240 Setup, 48V 105kWh Battery & Overkill 100A BMS Install

[PreppenWolf]

Did you determine the cause of current on EGC?

I have a circuit that runs the outlets in my living room that has grounds tied to neutrals. I haven't had a chance to investigate and correct yet.

 

[Zwy]

I have a circuit that runs the outlets in my living room that has grounds tied to neutrals. I haven't had a chance to investigate and correct yet.

That would do it. I noticed the current was small, usually an appliance in standby.

 

[PreppenWolf]

A production update. I am in SW New Hampshire. On the winter solstice with full sun day I made 10-11kW each day on Dec 20/21. Yesterday jist under three weeks later I am now making 15kW.

I really need to cut those Eastern tall pines down blocking my AM production. I was going to do some yesterday, but I pulled my back ?

 

[OffGridForGood]

But they were $61 each, so the cost savings is very high.

They are quoting these higher now I noticed, but depends also on quantity I am sure.
For a small order of 8 cells they want $72USD each. I noticed you bought a large quantity all at once, and the price likely reflects that volume.

 

[PreppenWolf]

I got (2) 60A single pole breakers to test a load case at the request from another thread.

Question from FilterGuy:

Your chart definitely shows the power going to the battery is throttled based on the setting of program 11 and that is exactly what I expected. However, it still does not answer my question. In the chart above the peak load is only about 5.25KW which is ~ 5250/120 = 43.75A.

What happens when the combined demand from both loads and charging exceeds the max 60A spec on the AC input?
(Note: 60amp on the input is ~60Ax120V = 7200W going to the combined loads and charging)

BTW: The chart is fairly self-consistent. Each jump is about 500W and that translates to 500/52 = 9.61 more amps to the battery. That is close enough to 10A to be within the error bar of my finely-tuned eyeball reading of the chart.

Found in this thread but I am posting here to keep info in one place for any others who build this type of system.

Had an electrician visit...

That is a good question that I have been grappling with on a different project. The EG4 Manual says the max AC input Current is 60A. There should be a 25% margin for the breaker, so I would recommend a 60Ax1.25= 75A breaker. HOWEVER: The manual also recommends 4AWG wire and that would be...

diysolarforum.com

 

[PreppenWolf]

My battery is currently at 51.0V, but when it hits 48.0V next and flips to bypass I will run a test where I bump the battery charge current up 10A at a time to see what the unit does when I exceed 60A draw on the grid supply line. The deeper question is will the unit shut down, or artificially throttle the battery charging to a lower level to avoid exceeding 60A for Batt + Bypass draw.

As a note I am using 90°C 6 AWG THHN wire for both the AC In wire and AC Out wire.

 

[John Frum]

As a note I am using 90°C 6 AWG THHN wire for both the AC In wire and AC Out wire.

Check the breaker that the wire is landed on.
The mechanical lugs on the breaker may de-rate the circuit to 75C.
This would limit the circuit to 52 amps continuous.

What is the temperature rating of the lugs on circuit breakers? | Schneider Electric USA

www.se.com

 

[PreppenWolf]

Check the breaker that the wire is landed on.
The mechanical lugs on the breaker may de-rate the circuit to 75C.
This would limit the circuit to 52 amps continuous.

It does. But I'm only running the test for under a minute. After that I'm throttling the charge limiter back down. 52A per leg is twice what my house peak load is per leg in summer with AC running.

ETA. I have a thermal cam. Will check the temp when I run the test

 

[PreppenWolf]

Added two analog 500VDC voltmeters to my PV lines tonight.

 

[bhavin66]

Banks without yellow labels haven't been top balanced. 3 down, 5 to go.

View attachment 128231

View attachment 128232

what is the dimension of that rack? does not look like a residential use or commonly available in store

 

[PreppenWolf]

what is the dimension of that rack? does not look like a residential use or commonly available in store

It is 60"W x 24"D x 78"H

I bought one at Home Depot last year and ordered the second off Amazon. The shelf only comes with steel grating for the shelves. I added the concrete board on top of the grating for both electrical insulation and as fire break.

The shelving is rated at 750lbs per shelf. Watch the rating as some versions are thinner gauge steel and only 500lbs per shelf. Which is probably still fine for most applications.

ETA: I just checked and the one I ordered on Amazon is not available anymore. It was also 750lbs per shelf so I adjusted the value above. I have roughly 300lbs on the full shelves.

 

[Zwy]

what is the dimension of that rack? does not look like a residential use or commonly available in store

Menards, Home Depot carry those in shelving.

 

[PreppenWolf]

I got the covered box in for the inside PV disconnect finally. Dear Lord I definitely should have done that from the start. What a bear to wrestle the wires into place.

 

[Adam De Lay]

Yeah it seems like they never give you enough room in those boxes. Had the same problem with my pv disconnect box. Ended up having to get a larger box just to deal with the wiring.

 

[PreppenWolf]

@John Frum & @FilterGuy

Tested the max charging on bypass today. I bumped both units to 120A on Setting 11 while on bypass/charge and placed clamp meters on both lines.

The units each throttled total 120V input amps drawn at 61A regardless of load I placed. Turning a Kobalt 1500W heat gun on while the line was measuring 61A draw led to a momentary (less than a second) blip of 68A, then immediate throttle at 60.5-61.0A.

So they are pulling back on battery charging amps when more pass thru amps are called for and doing it pretty fast. I did get a voltage sag from 117V to 113V when hitting the throttle. Our work computer UPS units didn't like that, my son reported they clicked to battery mode a few times for the 60 seconds I was at the limit.

This is good and means the 60A breaker is pretty spot on. I bumped both units down to 60A each on Setting 11 after the test. I don't need to charge at max rate.

I tracked temps. The breaker peak was 28.5C, open air wire peak was 22.8C and the 3/4" liquid conduit at the inverter AC Input was 23.5C max.

I've been running at 60A Setting 11 for 15min now and the breaker temp has come down to 23.5C. Clamp meter reports 54.8A to batts from 2P1 and 55.1A to batts from 2P2.


Pic of 2P1 AC In line from 60A breaker with Setting 11 set to 120A, house consuming
roughly 2kW and me turning the Kobalt 1500W heat gun on.

 

[PreppenWolf]

Forgot to add. I also got Warning 10 when it started throttling. It did not shutdown the system and it cleared immediately when I lowered the Setting 11 value.

 

[John Frum]

Are you aware of the 80% rule?

 

[Adam De Lay]

@John Frum & @FilterGuy

Tested the max charging on bypass today. I bumped both units to 120A on Setting 11 while on bypass/charge and placed clamp meters on both lines.

The units each throttled total 120V input amps drawn at 61A regardless of load I placed. Turning a Kobalt 1500W heat gun on while the line was measuring 61A draw led to a momentary (less than a second) blip of 68A, then immediate throttle at 60.5-61.0A.

So they are pulling back on battery charging amps when more pass thru amps are called for and doing it pretty fast. I did get a voltage sag from 117V to 113V when hitting the throttle. Our work computer UPS units didn't like that, my son reported they clicked to battery mode a few times for the 60 seconds I was at the limit.

This is good and means the 60A breaker is pretty spot on. I bumped both units down to 60A each on Setting 11 after the test. I don't need to charge at max rate.

I tracked temps. The breaker peak was 28.5C, open air wire peak was 22.8C and the 3/4" liquid conduit at the inverter AC Input was 23.5C max.

I've been running at 60A Setting 11 for 15min now and the breaker temp has come down to 23.5C. Clamp meter reports 54.8A to batts from 2P1 and 55.1A to batts from 2P2.


Pic of 2P1 AC In line from 60A breaker with Setting 11 set to 120A, house consuming
roughly 2kW and me turning the Kobalt 1500W heat gun on.
View attachment 129353

Thanks for testing this out!

 

[PreppenWolf]

Are you aware of the 80% rule?

Yes. I'm never going to be above 80% (48A on a one breaker) in regular operation and definitely not at 60A for more than 3 continuous hours.

3hr x 60A x 120V x 2inverters = 43.2kWh!
This is twice what my whole house uses per day in the winter from both on and offgrid panels combined.

Even if they made a single pole breaker higher than 60A for my panel, I'm not swapping the wire out.

 

[PreppenWolf]

We have another snowstorm coming here in NH. We already have snow/ice weighing down trees with 8-12" forecast and I'm expecting to lose power. I toggled settings on my 6500s to fully charge my battery bank. It's been charging at 85A (58.4V) each unit for two hours so far.

So 190A going into my bank. Each 60A breaker for AC In at around 50A @ 112VAC to charge and provide some bypass. No cable is over 30°C and most are around 25°C.

Warmest spot on the 60A single pole breakers from AC In to each inverter is 43°C, well below the 75°C rating.

Warmest spot on inverter metal body is 39°C. Notably there is a tiny spot on the control box that is at 60°C but I note previously this one spot is always warmer than the surrounding area.