Solar Install on 5th wheel

corn18

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I spent the last 2 weeks cleaning up the DC power system on my 5th wheel. Took out about 50 ft of wire and replaced with a clean install with 10' of total high amperage wire.

35183-albums227-picture2471.jpg


Next step is to add solar. I decided on the 400W system recommended here from Rich solar. Updating my diagram, the wiring seems straight forward.

Now:

35183-albums227-picture2468.jpg


With 400W solar:

35183-albums227-picture2469.jpg


Am I missing anything just for the solar install?
 

HRTKD

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Will the output of the Xantrex and the AC input of the AC-DC converter be on the same circuit? If so, that's a loop that will cause your batteries to be charged while they are being discharged by the inverter.
 

corn18

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Will the output of the Xantrex and the AC input of the AC-DC converter be on the same circuit? If so, that's a loop that will cause your batteries to be charged while they are being discharged by the inverter.
Negative. The Xantrax inverter is a single, dedicated circuit just for the residential fridge. It has an auto transfer switch built in that switches just the fridge between shore/generator power or battery power.
 
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HRTKD

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Negative. The Xantrax inverter is a single, dedicated circuit just for the residential fridge. It has an auto transfer switch built in that switches just the fridge between shore/generator power or battery power.

I did something similar with my Xantrex ProWatt 1000. It doesn't tie into the main distribution panel. Someday, I'll have a full size inverter that will.
 

corn18

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I did something similar with my Xantrex ProWatt 1000. It doesn't tie into the main distribution panel. Someday, I'll have a full size inverter that will.
I'm on a similar path. If I add a second LFP, I will add another inverter, too. The 2nd inverter will power one leg of my 50A system that has everything I want to run on it, except the fridge and converter. I will leave the dedicated inverter for the fridge as I want to be able to isolate the fridge and run just it on battery power while I am actually going down the road. If I put everything on one inverter, which would be much cleaner, then when I activate that one inverter, everything will have power and I don't want to go through the 5er and unplug stuff that doesn't need to be powered going down the road. Hope that makes sense.

This is what my final configuration should look like:

DC wiring 290RL all.jpg
 

Short_Shot

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The only thing I would question is the brand of your dc breakers and disconnect switch.

Lots of issues reported with the more inexpensive units on the market.
 

corn18

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The only thing I would question is the brand of your dc breakers and disconnect switch.

Lots of issues reported with the more inexpensive units on the market.
What is a good brand? I don't mind replacing them.
 

corn18

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I just ordered 3 Bussman circuit breakers and cutoff switch. Hope those meet the standard.
 
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HRTKD

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Bussman is good. It's the same brand that Blue Sea Systems resells I believe.

I didn't wire my two batteries together. Instead, each battery has it's own cable to the shunt on the negative side and to the fuse on the positive side. Eventually, I'll get around to providing a switch/fuse for each battery.
 

corn18

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I have all the parts on the way to finish my DC power install. Before I put everything in, would you take a look and see if there is anything I should consider changing? Especially WRT wire size and breakers. All wire runs are really short (<18") except the runs from the solar panels. I changed all the circuit breakers to Bussman and the main breaker is now a Blue Sea triple pole.

Thanks a bunch!

35183-albums227-picture2474.jpg
 

HRTKD

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If your 200w solar is ground deployed, I highly recommend a circuit breaker instead of a fuse. When my ground deployed solar panels are not in use, I turn off the circuit breaker. That way someone can't walk up and damage my system (much) by plugging in a high amp device. Yeah, I'm paranoid that way. The circuit breaker probably should be closer to 15 amps, not 30 amps like you have in the diagram unless you're paralleling your panels. A 30 amp circuit breaker or fuse between the 20 amp MPPT and the common bus bar is in order.

The 30 amp fuse on the PV side of the 40 amp MPPT is too high. Since your panels are in series, the incoming amps are probably no more than 10. I use a circuit breaker in this position also so that I can easily turn off the PV input during the day should I need to work on that part of the system.

I see a circuit breaker on the 1200 watt inverter, but not one on the 2000 watt inverter.

If your converter is off, how does the DC side of the trailer get power?
 

corn18

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The kit from Rich solar came with the 30A inline fuse from the panels to the charger. I thought it was a good fit for 10ga wire, regardless of what the amperage actually is. I learned on here that the fuse is sized to protect the wires.

I didn't put a circuit breaker on the 2000W inverter because the main CB @ 250A should cover that. I don't mind adding one for the 2000W inverter. What size? Seems they jump from 200A to 250A and I would prefer 225A.

Not sure I understand the converter question. The 2 positive wires on the converter (one comes in from batteries, one goes out to DC distro) are connected to each other via the input to the converter. The Progressive Dynamics Li converter/charger has dual positive posts that are bussed together. So when the converter is off, the DC distro panel gets power from the batteries. Hope that makes sense. I updated the diagram to reflect this.

Thanks for taking the time to look at this!
 

HRTKD

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I would not rely on a chassis connection to supply the negative side for either the converter or the DC distribution. I'm not a fan of daisy chaining circuits like you have there. I would run dedicated wires instead.

The fuse is sized to protect the wires. It's also located to protect the wires. Most fuses or circuit breakers are going to be positioned as close to the power source as possible. If you position the circuit breaker close to the converter, that works for when the converter is producing power to charge the batteries. But when the batteries are the power source, the circuit breaker is at the wrong end of the wire.
 

corn18

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I would not rely on a chassis connection to supply the negative side for either the converter or the DC distribution. I'm not a fan of daisy chaining circuits like you have there. I would run dedicated wires instead.

The fuse is sized to protect the wires. It's also located to protect the wires. Most fuses or circuit breakers are going to be positioned as close to the power source as possible. If you position the circuit breaker close to the converter, that works for when the converter is producing power to charge the batteries. But when the batteries are the power source, the circuit breaker is at the wrong end of the wire.

Let me take a closer look at how my converter and DC power panel are wired. I may have it drawn wrong.

It's a 4 ft run from the converter/charger to the battery busses. I could add a second 100A CB close to the converter for when it is in charge mode. Is that warranted with a 4ft run? I guess if the converter/charger shorts while in charge mode, that is 4ft of wire that could melt or catch on fire.
 

corn18

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I would not rely on a chassis connection to supply the negative side for either the converter or the DC distribution. I'm not a fan of daisy chaining circuits like you have there. I would run dedicated wires instead.

The fuse is sized to protect the wires. It's also located to protect the wires. Most fuses or circuit breakers are going to be positioned as close to the power source as possible. If you position the circuit breaker close to the converter, that works for when the converter is producing power to charge the batteries. But when the batteries are the power source, the circuit breaker is at the wrong end of the wire.
@HRTKD You are brilliant! I have no idea how you spotted that chassis ground problem at the converter. The converter negative goes to a bus bar. Lots of DC stuff hooked to that bus bar. A 6ga wire goes to the DC power panel. Another 6ga wire goes to who knows where. It drops down under the trailer and I have no idea where it comes out. It did not come out in the front storage area where the batteries used to be.

So, I am going to add a wire running from the second - post on the converter back to the main DC bus bar in the basement.

Thank you!

DC wiring 290RL 11.jpg
 
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corn18

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UPDATE:

I redid the install and eliminated the Chinese stuff. The main breaker is now a 3 pole 250A from Blue Sea mounted in a box. Went with 4/0 for the main battery cables up to the bus bars. Then 2/0 to both inverters. 2ga to the converter. I dropped the breakers for the inverters. The main breaker will protect those 2/0 wires fine. Besides, I couldn't fit 4/0 lugs into the inverters and didn't feel I needed an additional breaker for 2/0 wire. That stuff is a beast.

I have a second SOK 206Ah LFP on order. Should arrive next week. The 2x200W solar panels are in but it's raining, so that'll have to wait. And still need to heat shrink the connections.

DC wiring 290RL diagram.jpgDC wiring 290RL pic.jpg
 

corn18

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Made a couple more mods.

I added an inverter precharge circuit because my BMS was going into protect mode when I flip on the 250A breaker. Didn't happen with the smaller wires and Chinese CB and cutoff switch.

Added an 18A DC-DC charger in the line from the truck. Works like a champ.

Moved the output from the roof MPPT controller from the + bus to the + battery terminal. That way the batteries are always charging even with the main 250A breaker off.

DC wiring 290RL.jpg
DC wiring 290RL pic.jpg
 

corn18

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Working on the brackets for my 2x200W panels. Going with the standard 1 5/8" aluminum strut channel 17" apart. Made my own tilt mounts because I wanted to use rivnuts to minimize hardware when tilting. So, I have 4 mounting points across the center. Used 2" aluminum angle iron to make the tilt brackets so the panels will sit 3 5/8" off the roof. Seems good for ventilation. I am also adding 2 aluminum L brackets on the leading edge that will be secured to the strut channel with male knobs. I like the added security and if I ever want to tilt the panels I can just unscrew the L brackets. I doubt I will ever tilt them, but why not build in the capability?

So, is 6 attach points secure enough? I could add 2 more L brackets on the trailing edge, but that seems like overkill. I really just need to keep it from ripping off of the strut channel.

IMG_4933.jpgIMG_4932.jpg
 
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corn18

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Got the second SOK 206Ah in and installed it. Also installed the solar charge controller. Haven't mounted the panels yet.

DC wiring 290RL.jpg
 
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