Finally Starting My Solar Install

[Kendorado]

Of course you can route the wires under the panels. As far a being too concerned about shading, Last I heard was the sun moves so what's being shaded now will be unobstructed in 15 minutes

[Uniblab]

Congratulations, you will be thrilled with the results!

If I had to choose I would take the lower photo because it is a more efficient use of space, however I would add one or more panels to fill the remaining open space (in the position indicated in the upper photo, at the rear of the coach). More is always better. I assume these are 36-cell panels producing a maximum open circuit voltage of ~21V. Your controller has plenty of capability to handle a 7th, or even 8th panel if you can still get matching ones. Again, more is always better!

Originally Posted by rfg9585

Below are 2 pics of my possible layout for this. What design do you think would be better and why?

Thanks!

[rfg9585]

Originally Posted by Uniblab

Congratulations, you will be thrilled with the results!

If I had to choose I would take the lower photo because it is a more efficient use of space, however I would add one or more panels to fill the remaining open space (in the position indicated in the upper photo, at the rear of the coach). More is always better. I assume these are 36-cell panels producing a maximum open circuit voltage of ~21V. Your controller has plenty of capability to handle a 7th, or even 8th panel if you can still get matching ones. Again, more is always better!

Thanks! We think alike, as that's the one I am going with. Right now testing products for adhesion to my roof. Soon will start laying them down to complete my project.

Also retesting my battery\wiring\misc setup again tomorrow(post #56). Hopefully all works well....

[757driver]

Originally Posted by rfg9585

Houston, I may have a problem. Unplugged from shore and sitting on 12.5 volts and 93% SOC according to my BMV712, I started my little space heater which I have done before with just 4 batteries. Within a few minutes my inverter shutoff with low battery alert in the remote panel.

The low V shutoff was set at 11. Not sure if this is related to the work I've done with the solar or the new set of 6 T105 batteries. I may have changed the low battery shutoff to 11 by mistake, not sure.

After the inverter shutdown my BMV712 still shows 12.4 V.
I have reset the low battery shutoff to 10 and hopefully its still running.

Do I have an issue or did I set things incorrectly on my inverter.

Thanks!

With that high of a load on your batteries the indicated voltage on the Magnum remote can and will drop very quickly. Try setting a LBCO at about 10.5v and see if that works better.

[mtnbrit]

What size and length of cable do you have between the batteries and from battery bank to inverter? Shorter and thicker is better obviously, at least 4/0 cable, if not 2 of them doubled up when pulling 200A over more than say 5ft.

[StepandWolf]

Originally Posted by rfg9585

A year ago I bought 6 225w panels from Hightec solar on ebay. This past week I put in 6 new Trojan t105s with a watering system. Now I have the rest of my components on the way from N Az Wind and Sun, which will arrive Monday. It will include a Victron 250\100 controller and a BMV712 monitor plus all the wires, connecters, fuses, breakers, etc.

All being said I started my layout today and I would like some advice to start with. I plan to wire the panels in 1 series and feed the wire thru a conduit I placed in the fridge shaft when I done the res fridge.

Below are 2 pics of my possible layout for this. What design do you think would be better and why?

I will use this thread to update\ask further questions about my project.

Thanks!

Two comments as I am starting an install soon.

1. I don't know why people are still using flooded lead acid batteries. On the solar forum I participated in a group buy on lithium cells. I ordered 8 272ah cells for $800. That means 544AH at 12V for less than 6 Trojans. Lead acid batteries can only be used for 50% of capacity vs. 80+% for Lithium. Lead acid batteries have a fraction of the life of lithium. Lithium cells don't need to be vented. Six Trojans weigh 360#, 8 lithiums weigh about 100# and take up less space. No watering system needed

2. Regarding mounting the panels. I haven't done it yet, but I am also installing six panels in one row and will be installing them three in series for 24V total. 24V will allow for a smaller gauge cable than 12V. I intend to use 3/4" square aluminum stock Alumiwelded together. Rather than bolting each panel to the roof, they will be bolted to the frame. The frame will be raised off the roof for ventilation and rain flow underneath with the interior legs being shorter than the outside legs to make the panels level. I might decide to make them tiltable. By installing the rack system I can bolt them into the frame members, not in random places based on panel size. I will also have roughly half as many holes to put in the roof which is always a good thing.

As my panels will be running along the edge of the roof, and if I tilt them, there will be no sun blockage by vents, AC, etc. Even if I don't tilt them, they won't be in a shadow. I learned the trick to park facing west so the panels will tilt to the south and the patio side will be on the shaded north side.

An option to welding aluminum you can use the 8020 extruded rail material which costs more but is less labor. Your choice on whether you would rather spend more for material vs. more labor time doing welding.

I didn't price the extruded aluminum option but all the square stock needed is about $250 for my setup buying the stock locally. Alumiweld rods come from Harbor Freight and can be welded with propane or MAP gas as you desire, i.e. no sophisticated welding setup or skill needed.

The underside of the rack is a great way to route cabling, keeping the cables off the roof and out of the sun. My panels happen to run over the TT factory-installed cable entry so I will have no visible cables.

Just my 2c worth which after inflation is about 1c worth

ps: If you compared against Battleborn or similar for your lithiums, you might have viewed FLA as cheaper. Since it is incredibly simple to build your own battery bank, there is no reason to go with already built battery packs and the huge profit built in to their prices.

[cruizerEd]

Magnum states that without the Magnum BMS installed so that you can use the remote voltage sensing inverter voltage measurements are not very accurate.

The problem is the putting a magnum BMS in for just remote voltage sensing is kind of a waste considering you have other better battery monitoring. Perhaps with some digging you can figure out how to just wire up the remote voltage sensing.

One 1500 watt load will probably pull about 150A from your batteries. That isn't crazy high but if you cable run is long or you your cables are on the small size it will not only drop the voltage but waste a lot of energy warming up the cables. When calculating cable length you have to measure the positive and negative length.

[rfg9585]

Originally Posted by mtnbrit

What size and length of cable do you have between the batteries and from battery bank to inverter? Shorter and thicker is better obviously, at least 4/0 cable, if not 2 of them doubled up when pulling 200A over more than say 5ft.

Whoever installed it put in 3/0 welding wire cable and its at least 15ft. I used that to connect to my busbar and then ran about a 2/0 cable about 2ft to inverter.

I know 3/0 15ft is not the norm, but it is what it is.

Not now, but when I move to lifepo I will make a BIG attempt to rerun 4/0.

[rfg9585]

Originally Posted by StepandWolf

Two comments as I am starting an install soon.

1. I don't know why people are still using flooded lead acid batteries. On the solar forum I participated in a group buy on lithium cells. I ordered 8 272ah cells for $800. That means 544AH at 12V for less than 6 Trojans. Lead acid batteries can only be used for 50% of capacity vs. 80+% for Lithium. Lead acid batteries have a fraction of the life of lithium. Lithium cells don't need to be vented. Six Trojans weigh 360#, 8 lithiums weigh about 100# and take up less space. No watering system needed

2. Regarding mounting the panels. I haven't done it yet, but I am also installing six panels in one row and will be installing them three in series for 24V total. 24V will allow for a smaller gauge cable than 12V. I intend to use 3/4" square aluminum stock Alumiwelded together. Rather than bolting each panel to the roof, they will be bolted to the frame. The frame will be raised off the roof for ventilation and rain flow underneath with the interior legs being shorter than the outside legs to make the panels level. I might decide to make them tiltable. By installing the rack system I can bolt them into the frame members, not in random places based on panel size. I will also have roughly half as many holes to put in the roof which is always a good thing.

As my panels will be running along the edge of the roof, and if I tilt them, there will be no sun blockage by vents, AC, etc. Even if I don't tilt them, they won't be in a shadow. I learned the trick to park facing west so the panels will tilt to the south and the patio side will be on the shaded north side.

An option to welding aluminum you can use the 8020 extruded rail material which costs more but is less labor. Your choice on whether you would rather spend more for material vs. more labor time doing welding.

I didn't price the extruded aluminum option but all the square stock needed is about $250 for my setup buying the stock locally. Alumiweld rods come from Harbor Freight and can be welded with propane or MAP gas as you desire, i.e. no sophisticated welding setup or skill needed.

The underside of the rack is a great way to route cabling, keeping the cables off the roof and out of the sun. My panels happen to run over the TT factory-installed cable entry so I will have no visible cables.

Just my 2c worth which after inflation is about 1c worth

ps: If you compared against Battleborn or similar for your lithiums, you might have viewed FLA as cheaper. Since it is incredibly simple to build your own battery bank, there is no reason to go with already built battery packs and the huge profit built in to their prices.

I agree that lifepo is cheaper and its probably very easy for the confident\knowledgable to do so. But its taken me a year to finally understand the minimum about solar to be confident that I can install it myself. Maybe next year I will do lifepo, who knows. I am not ready yet as there are more issues to deal with on my coach due to alternator, BIRD, ME2012 inverter, etc.

[rfg9585]

Originally Posted by cruizerEd

Magnum states that without the Magnum BMS installed so that you can use the remote voltage sensing inverter voltage measurements are not very accurate.

The problem is the putting a magnum BMS in for just remote voltage sensing is kind of a waste considering you have other better battery monitoring. Perhaps with some digging you can figure out how to just wire up the remote voltage sensing.

One 1500 watt load will probably pull about 150A from your batteries. That isn't crazy high but if you cable run is long or you your cables are on the small size it will not only drop the voltage but waste a lot of energy warming up the cables. When calculating cable length you have to measure the positive and negative length.

Sounds like cable length is contributing to the over-drain. See response to MTNBRIT.

[rfg9585]

Need advice on covering\protecting circuit connections. See post#50. In it I will have a cover for only the + busbar and the incoming PV wire. The other connections are exposed. What can I do to protect\insulate the other connections?

[StepandWolf]

Originally Posted by rfg9585

I agree that lifepo is cheaper and its probably very easy for the confident\knowledgable to do so. But its taken me a year to finally understand the minimum about solar to be confident that I can install it myself. Maybe next year I will do lifepo, who knows. I am not ready yet as there are more issues to deal with on my coach due to alternator, BIRD, ME2012 inverter, etc.

I found the Will Prowse videos excellent but I found another source of even better information regarding how to set a system up:

https://www.explorist.life/50a-campe...iring-diagram/

He has the best drawn, most complete diagrams. He shows a variety of configurations with every single wire, connector, etc. defined. He even provides a shopping list of parts. He is also available for paid consults. His diagrams can be printed in hi-res with a freely provided PDF.

He also developed a wire gauge and fuse size calculator. If you have the cajones to do what it sounds like you are doing, you should definitely be able to follow this guy's instructions.

There is very little difference between a FLB install vs. lithium install, just a big savings, longer life, and far less hassles and weight.

[StepandWolf]

Originally Posted by rfg9585

Need advice on covering\protecting circuit connections. See post#50. In it I will have a cover for only the + busbar and the incoming PV wire. The other connections are exposed. What can I do to protect\insulate the other connections?

It doesn't look like there is any danger from shorting between the components assuming none of the connections become disconnected. If you want to protect the whole board, maybe a piece of fiberglass cut to cover the whole thing with standoffs to connect it to. The first thing that came to mind is those green roofing panels, the corrugated ones. One piece could be cut to protect the whole thing. I first thought of plex, but it is brittle and could be broken whereas fiberglass can take more punishment, You could even double it up. The corrugation will help for airflow.

Nice wiring job!

[rfg9585]

Originally Posted by StepandWolf

It doesn't look like there is any danger from shorting between the components assuming none of the connections become disconnected. If you want to protect the whole board, maybe a piece of fiberglass cut to cover the whole thing with standoffs to connect it to. The first thing that came to mind is those green roofing panels, the corrugated ones. One piece could be cut to protect the whole thing. I first thought of plex, but it is brittle and could be broken whereas fiberglass can take more punishment, You could even double it up. The corrugation will help for airflow.

Nice wiring job!

Good idea! I have some lexan which is clear and could make a sheet the same size and stand it off from the critical pieces.