6000W solar and inverter upgrade!

[kazetsukai]

I think I'll chronicle my solar upgrade here. Recapping: I have a bus conversion with 3000W of solar on the roof, an 8000W PowerJack (v10.3+) inverter that has generally served me well, but would overheat under some circumstances. Worth every penny, would buy again, etc but Genetry Inverters both being true-to-rating and having enhanced/smart cooling functionality made the choice to upgrade very easy.

Additionally I am moving away from a pair of Tesla batteries to a 43kWh LFP bank and want to be able to charge the bank to 80% in one day of full sun, so I am also doubling up on solar panels from 3000W to 6000W. A tricky proposition, as my roof is currently full:

The idea is to build a slide-out system capable of accommodating another 8 to 10 panels, which I am working on today.

Well, in the middle of this effort, UPS pulled up to deliver a package. I thought it was some 100% fruit juice ice popsicles I ordered a week ago, turns out it's the beast I pre-ordered back in October!

So now I have some choices to make! My current inverter lives in a box under the bus.

This box is where I plan to locate the new battery bank, (well insulating it and installing climate control) but I'm not sure I want the inverter there or not.

Also, it would be pretty easy to swap out the PJ for this GS inverter as it is on the current Tesla bank, which voltage range is 40v-48v... It would be good to test this thing prior to the new bank arriving.

I need to get this metal painted, after which I can post an unboxing!

Thank you Sean and Sid!

 

[The Blind Wolf]

What kind of bus you got?  Is it a old school bus convert?

[kazetsukai]

1 minute ago, The Blind Wolf said:

What kind of bus you got?  Is it a old school bus convert?

It's a 1999 International with a Rear Engine. International still makes this chassis so it's not "old school" per say.

[Sid Genetry Solar]

Thanks @kazetsukai, we hope it works very well for you.  Sorry it took SO long to get...we are probably making all the "startup" mistakes that can be made, but thank you for your patience.

[kazetsukai]

6 minutes ago, Sid Genetry Solar said:

Sorry it took SO long to get...we are probably making all the "startup" mistakes that can be made, but thank you for your patience.

To diverge briefly on this topic, @Sid Genetry Solar @Sean Genetry Solar:

Mistakes were going to be made no matter who it was, and seldom does anyone get to choose which mistakes are made. I judge based on how mistakes are addressed... Throughout this entire process Genetry Solar has been transparent, open, and accessible, enough for an A++ rating in my book. 

I don't need an apology, this is what I signed up for. I wish you guys the best.

 

[The Blind Wolf]

Finally, I got it to load :P.

 

Yeah, I got a 1988 International 24 foot box truck.  uns like a champ even after a year of not starting it, put a batty to it and fired right up and moved it to another spot.

 

I would love to find a empty bus like that you got. where do I look to buy one used and still running of course lol.

[kazetsukai]

Just now, The Blind Wolf said:

I would love to find a empty bus like that you got. where do I look to buy one used and still running of course lol.

The forums I frequent over at https://www.skoolie.net/forums/has a classifieds section, and there's also govdeals.org, etc. Lots of places to find them, although pre-emissions diesels are getting harder to find (2007+ are frowned upon because the emissions equiipment often causes engines to blow up).

I've been thinking of starting a business to help with conversions.

[The Blind Wolf]

Well, I rebuilt the whole box inside the box truck new wall instulation wireing and all that, so a bus wouldn't be much diff, other then dealing with all those dang windows, which would be easy to get rid of by taking them out get a sheet a metal and rivet it in then seal it of course before riveting.  I would probley wrap the dang thing would be cheapier then painting lol.

[Sid Genetry Solar]

@kazetsukaiCurious how the GS inverter's doing for you?

[kazetsukai]

So yesterday, the rest of my batteries finally arrived. We started assembly immediately:

 

Custom aluminum bus bars spanning six cells to make both the series and parallel connections in one swoop. Pretty sure these will perform well, if not I'll have some nickel plated copper ones made later on.

You can see my masking-tape covered torque wrench at the bottom of the photo above, taking every precaution with assembling these. 48 cells in 16S3P.

Behind, inbetween, and in front of these cells I'll be placing some RV heat pads:

 

They have a built-in thermostat, but I'll also add my own themostat to drive both these and a warning light in the cabin. This is my safeguard against freezing.

Yesterday I got through about half the cells. 

BMS is beefy as heck:

Using some runs of "PVC wood" to act as barriers between the bus bars (prevent accidents), a platform for a protective cover. I cut channels in these barriers for the BMS balance leads:

Today hopefully I can finish up assembling the bank. After that I have to top balance the cells- I'm going to do this by charging the bank at once up to a modest voltage (3.4V per cell, 54.4V bank), then increasing the target bank voltage by .2V until I reach 3.55V for every cell. Any stragglers I'll charge individually with a bench power supply to bring them up. If I have peaking cells, I'll use the bench supply to hit the lowest ones until they are caught up. Top balancing them all in parallel would take far too long from factory SoC with my power supply.

After a top balance, I'll remove my Tesla packs and install the shiny new GS inverter, finally!

 

 

 

 

 

 

 

 

[kazetsukai]

Lower half of the battery bank balance lead bars installed:

[kazetsukai]

Yesterday we finished base assembly:

Now I have some cleanup to do in the electrical cabinet, reorg/moving stuff.

 

That used to be rather neat- incrementalism is to blame. The hanging positive leads go nowhere at the moment- they were to the PJ inverter but will be used now instead to go to the new batteries. Also intend to vacate the lower section today, for the GS inverter:

4

 

Tesla packs on the right, NAS/landslide of electrical goodies that never belonged there on the left. New home for the GS inverter.

Lots of work ahead of me today....

 

 

 

 

[kazetsukai]

@Sid Genetry Solar @Sean Genetry Solar 

So, some unfortunate news- seems the front output terminals of my 6kW GS inverter were busted in shipping. Could you send another matching terminal block?

 

[The Blind Wolf]

2 hours ago, kazetsukai said:

@Sid Genetry Solar @Sean Genetry Solar 

So, some unfortunate news- seems the front output terminals of my 6kW GS inverter were busted in shipping. Could you send another matching terminal block?

 

Wow, how that happen?  the cover should have prevented the terminal from busting, unless the cover was bent like heck.  I can't see, so don't know what it looks like.  Thats UPS for you, drop mine off and bent the heck out of it and cause a wire to get loose to fry it under a load.   

[Sid Genetry Solar]

6 hours ago, kazetsukai said:

@Sid Genetry Solar @Sean Genetry Solar 

So, some unfortunate news- seems the front output terminals of my 6kW GS inverter were busted in shipping. Could you send another matching terminal block?

 

Sorry for the damage; turns out we're actually out of stock of these right now, so we'll order some more in and get a replacement one off to you ASAP.

Will PM you also.

[kazetsukai]

23 minutes ago, Sid Genetry Solar said:

Sorry for the damage; turns out we're actually out of stock of these right now, so we'll order some more in and get a replacement one off to you ASAP.

Will PM you also.

Its not like either of you did it... Both covers were fine, oddly enough. 

I have to say this is a very nice looking inverter, probably the nicest I've seen thus far! Stainless and shiny!

Finished swapping out the batteries today, but ran into trouble with the Daly Smart BMS. I must be missing a temp sensor or something, as there's a related fault code on the BMS preventing charge/discharge, and the one sensor reads -40C. I'm reaching out to Daly about it but I have my doubts as to whether they'll be responsive... So for now I'm going to charge to 54.4V, and keep an eye on the cells manually while I look for a new BMS.

 

[kazetsukai]

Today I was able to replace the output terminals:

Getting ready to hook it up!

I did acquire some of the "new connectors" currently being used but decided against using them. They are quite a bit smaller, which is nice, but the current terminals are far beefier than anything I've had on a PJ inverter.

Finally I built some 4/0 cables to hook it all up:

The new 43kWh LFP bank is charged full:

35kWh into the bank, so SoC was around 20% on arrival.

 

[kazetsukai]

In light of some conversations around 240V charging problems, I've decided to hook up the inverter as I had my PJ inverter- output only to a manual changeover switch, no input/ATS/charge.  ATS/charge were two of my most anticipated features- the cool as heck ones I've been waiting for. Just plug in an the inverter would switch over and charge from shore- sweet!

However,  the lack of a double-pole relay internally to disconnect L2 causes issues with my use case. My use case means I cannot avoid a ground/neutral bond upstream of the input, and I must assume ground is shared between N-input and N-output as I only have one ground available to me, I need a ground connection to chassis, etc. In retrospect I should have given 120V charge a little more consideration (for other reasons, primarily generators) but I do believe 240V input is the way to go for me. 

Every outlet in my bus is GFCI... which recently actually protected me from shock when my 10+ year old fridge developed a ground fault three weeks ago- apparently compressors can develop ground faults when they are near failure. We had a pretty big ordeal replacing it with something brand new from the store...

So... a bit disappointing. What I would like to do is install the inverter as the ATS- running only inverter output to the AC panel and the shore inlet to inverter input, so that I can take advantage of ATS/charge, and later have computer control over ATS/inverter modes. It would also render me immune to problems like open neutral at faulty pedestals. Perhaps I could buy a newer revision board with the double pole relay and retrofit it later... hopefully for the time being I don't have to plugin at all =).

Edited June 30, 2021 by kazetsukai

[kazetsukai]

@Sid Genetry SolarI got it hooked up, powered on. Fans spin up hiGH then go silent. But as I was playign with the BMS (temp sensor) one of the times the inverter came back on, it came on with a red light + beeeeeeeep. I couldn't see the screen, don't remember if it was blank or what. Turned it off and waited a little while... now I hit the button, it turns green and no activity. Uh oh...

No smell or anything, just silent with a green light. No WiFi board screen.

[kazetsukai]

Oh, it came on again this time after letting it sit a while. Having the BMS cut out power on it like that must have put it into a weird state.

[kazetsukai]

Nope, something is wrong. After a while it has a fast blink red with the beeeeeeep. 

[Sid Genetry Solar]

19 minutes ago, kazetsukai said:

@Sid Genetry SolarI got it hooked up, powered on. Fans spin up hiGH then go silent. But as I was playign with the BMS (temp sensor) one of the times the inverter came back on, it came on with a red light + beeeeeeeep. I couldn't see the screen, don't remember if it was blank or what. Turned it off and waited a little while... now I hit the button, it turns green and no activity. Uh oh...

No smell or anything, just silent with a green light. No WiFi board screen.

Will PM you.  Sounds a bit like something isn't plugged in.

I will note that the transformer is almost dead silent at idle.  If you're used to the loud buzz of a PJ...it's not going to be there.  But the LCD should be lighting up when you turn the power on.  Fans speeding up fast for a few seconds is normal startup behavior, and would normally indicate the LCD board is working.

[kazetsukai]

Well, thanks to help from  @Sid Genetry Solar with the inverter the past couple days, I got it running yesterday. He also resolved the charge/ATS issue for me, so I'll be gearing up to get that all installed here shortly. Since yesterday evening the inverter has been humming away in its new little home:

All looked well:

Shortly after I calibrated it, switched bus power over to the inverter and went to bed. I set it so the fans would stay on low rather than spin up every so often, made it easier to sleep. I wonder if I could get the fan speeds a little lower even for the "fan off" setting.

Today without realizing it I had kicked off a mini stress test when I went about my business and threw a pizza in the oven!

 

120V Ninja convection oven, pulls around 1800W-2000W.

 

Remote display is such a cool feature for times like these...

 

Solar input jumped with the new load:

 

And my yield today has been a bit higher after running the AC all night! Looks like I have a solid 6-7 days of standby power for extended overcast with this new battery bank.

 

Overall super excited to see this all come to fruition. Its been months in the making.

Thank you Genetry Solar!

*munches on solar cooked pizza*

Edited July 8, 2021 by kazetsukai

[kazetsukai]

Yesterday I ran the above oven for a little over two hours, no hiccups at all. Knowing virtually nothing about how the fans are programmmed, behavior seems like it could be better- I would see fans spin down when load was high (oven elements switch on/off based on internal oven temp) only to spin back up when temps rose again. Also, when the food was finished cooking the fans continually readjust while the inverter as a whole cools down. I think cooling back down to average temperature should be done more consistent and aggressively, then shut the fans down to their minimums rather then modulate down. Ultimately keeping the inverter cool is the highest priority... its just more "user friendly" if the fans adjust as infrequently and gradually as possible. Just an idea!

Anyway I knew the already warm cabinet would probably not be a great environment for the inverter, so yesterday I installed an exhaust vent in the cabinet. Air at the top of the cabinet is sucked directly outside. 

(image of cabinet with vent fan)

(

Now this creates negative air pressure in the cabin, causing air from anywhere it can enter to enter (mostly at the front door), but I think this is a win compared to the alternative of much hotter air in the cabinet leaking out into our hallway. The air blowing out does feel hotter than the summer ambient air outside.

The blower fan is thermostat controlled, so it will throttle itself as needed. Its silent on the highest setting... I have another one of these fans below in the battery compartment.

During winter this vent will be capped and not operate, as will the battery box vent.

 

[Sid Genetry Solar]

2 hours ago, kazetsukai said:

Yesterday I ran the above oven for a little over two hours, no hiccups at all. Knowing virtually nothing about how the fans are programmmed, behavior seems like it could be better- I would see fans spin down when load was high (oven elements switch on/off based on internal oven temp) only to spin back up when temps rose again. Also, when the food was finished cooking the fans continually readjust while the inverter as a whole cools down. I think cooling back down to average temperature should be done more consistent and aggressively, then shut the fans down to their minimums rather then modulate down. Ultimately keeping the inverter cool is the highest priority... its just more "user friendly" if the fans adjust as infrequently and gradually as possible. Just an idea!

It is a fine song and dance, I must admit.  I'm open to viable suggestions and ideas; currently the fan speeds are directly controlled by the measured temperatures (as sort of detailed in the manual).  These temperatures (as you noticed) lag behind the load on the inverter, as does the generated heat.

The constant rise/fall of temperatures can be caused either directly (as a result of the increased fan speed cooling the heatsink) or indirectly (noise in the measurements and/or different thermistors switching control on the fans).  The fans add their own delay to PWM throttle control as well.

If you'd like the fans' minimum speed to be directly determined by the total load on the inverter, you can use the ProCool settings (Proactive Cooling) on the appropriate fan channels.  These will ramp the fans up directly based on the load, regardless of temperature--and if the temperature rises past the "minimum" set by ProCool, the fans will throttle past that.

You can tweak the fan settings, but please make sure you understand what they do before you adjust them.  Sean has reported several problems with customers messing with fan settings they didn't understand, resulting in the inverter overheating...or really weird fan behavior.  (One of those got all the way to me having to spend half an hour on the phone with the customer to reset the default fan settings.)  Unfortunately, this means that we will have to lock the default fan settings (which we will be tweaking a bit) unless the inverter is unlocked.  I don't like to do that, BUT...there's unfortunately a reason that lawn mowers are plastered with warnings saying, "Sharp blades, do not stick your hands under the mower deck."