From fire truck to MTV

[aw113sgte]

UPS is working overtime... The major electrical components have arrived.

 

[MatthewWBailey]

UPS is working overtime... The major electrical components have arrived.
View attachment 919683View attachment 919684

What size kw will that be once mounted?

 

[aw113sgte]

What size kw will that be once mounted?

2200w solar, inverter is 3000w continuous

 

[MatthewWBailey]

2200w solar, inverter is 3000w continuous

Wow that's a nice big number, for a vehicle. I've seen some spec homes that only had 3k on the roof. Pretty cool

 

[aw113sgte]

Got the main electricals mounted. The batteries (3x 24V LiFePO4 victron, 15.3kWh) will be underneath the inverter/chargers.



I think this will be the location for the water heater and fresh water tank.


Someone asked a while ago, this is with the cab tilted and it's door closed. It has a seal all the way around.


Hydronic heater mounted with it's expansion tank.




Diesel fuel pickup for the heater installed. Nice that there was already a standpipe in the tank at the secondary port. Made for a very easy install.

 

[phuriousgeorge]

Tons of progress in a relatively short period of time, I'm impressed! I tend to suffer mental vapor-lock with all the various ideas running through my head.

 

[antennaclimber]

Your Uni-Strut looks great!
It's the adult version of the Erector sets we played with as kids.

 

[ckouba]

Is the alu tank your header tank? You will likely want to move that indoors somewhere. Otherwise, your 150° glycol will be chilling rapidly while waiting for its trip through the heater. Even just moving it inside the passthrough would likely make a world of difference.

 

[aw113sgte]

Is the alu tank your header tank? You will likely want to move that indoors somewhere. Otherwise, your 150° glycol will be chilling rapidly while waiting for its trip through the heater. Even just moving it inside the passthrough would likely make a world of difference.

It's the expansion tank, the only flow into/out of it will be from coolant expansion-no circulation through it. Sure there may be a little of it mixing in the system from turbulence but I doubt it will be significant. The main coolant lines will most likely get some insulation.
I think it will work well but will see!

 

[ckouba]

Got it. I ran my flow through it to make sure air purges, so mine heats up. I have heater and ~4 total feet of hose running outside of the hab. Everything else is quite purposefully indoors.

 

[aw113sgte]

Mounted solar panels today, 2200w residential. 4 points of attachment, M8 riv-nuts into roof. Sealed with sikaflex 221. Zinc chromate 10.9 fasteners.

Didn't even fall off the roof once!

 

[chucky]

Mounted solar panels today, 2200w residential. 4 points of attachment, M8 riv-nuts into roof. Sealed with sikaflex 221. Zinc chromate 10.9 fasteners.

Didn't even fall off the roof once!

View attachment 920859

Did you hook the cables up in series or parallel

 

[aw113sgte]

Did you hook the cables up in series or parallel

Haven't done it yet, based on voltage and current ratings I can do either. I'm currently thinking I'll series each set of 2, then parallel those 3 sets

 

[MatthewWBailey]

Haven't done it yet, based on voltage and current ratings I can do either. I'm currently thinking I'll series each set of 2, then parallel those 3 sets

Did you do your cold Voc calculations ?

 

[aw113sgte]

Did you do your cold Voc calculations ?

MPPT controller can handle 250V, each panel is 48 VOC per datasheet. I could easily do 3 in series in 2 sets with lots of headroom. I'll probably do 2 in series with 3 sets - to optimize generation with shading. Each panel is just below 10A so I could run the 3 sets into one set of cables and be under the 30A limit of MC4 connectors. Open to thoughts.

 

[MatthewWBailey]

For efficiency, you always want to maximize your voltage into the inverter, which in turn minimizes the amperage. Obviously both are hard limits but on paper you're also trying to minimize your wattage losses from the wiring. I did some Rough Voc calcs which typically show +10-12% Voc at -20C ambient startup temp on most panels. So 1.12*48=53.76. If you do 3 in series, you have plenty of space below the threshold, 161.28v < 250. The closer you can get to the max voltage, the better, as long as you're using the cold Voc value. It's just an efficiency preference since your wiring is probably #10 or max #8. Lower current, lower losses. 2 in series is 107.52v and now you're closer to the lower DC activation voltage which I don't know for your model, probably ok unless 1 panel is shaded. for Example, If you had the room you could go 4/4 and be at 215v but that's too much roof space probably. Comparatively, on a groundmount, if I wanted 5 series panels, I'd need to select a model that has a VOC below 44.5v to stay below 250 total with cold Voc. That's where the purchasing dance competes with energy production. I think yours at 3/3 is the best for minimizing losses.

 

[hike]

I agree maximize voltage, reduce amperage. Let the MPPT and converter do their work; invert as little as possible—

 

[aw113sgte]

Problem with series is shade, have lots of deciduous trees around here so if a single panel is shaded, it would kill half my output. (From my very limited research) I plan to look at some technical reports, forums seem to be ripe with opinions instead of facts from the RV community.

 

[aw113sgte]

Got a few of the storage boxes for the interior (harbor freight) unfortunately one came dented but too much effort to return and wait for another few months so a hammer and paint is the solution.

Also mounted the air/water heat exchanger. Rock solid with the unistrut. Got the motor drivers too and tested them out with the heat exchanger fans and some LEDs (Arduino control) and they worked perfectly. Have a 24v battery bank and am trying to keep all needed items at that voltage to limit conversion losses.

Also dug though my old man pin of wires and found a 4x20 LCD and a keypad so that may be the way to interface with the system.

 

[hike]

Problem with series is shade, have lots of deciduous trees around here so if a single panel is shaded, it would kill half my output. (From my very limited research) I plan to look at some technical reports, forums seem to be ripe with opinions instead of facts from the RV community.

1— depends upon the panels them selves;
2— with panels properly spaced above the roof shading does little to aid cooling the habitat and panels, the panels act as a radiator absorbing and emitting the heat. Leaving the habitat cool, bi-facials are better;
3— in series requires an MPPT, not a PWM controller to obtain more power output.