roof rack for solar

[pianotuna]

Since I'm committed to 12 volt because of a pure sine wave inverter, if I upgrade I will go MPPT with the Magnum PT-100. That would allow me to install 1200 watts of solar. To do that would require a roof rack that goes above the air conditioner.

How much clearance would I need above the air conditioner shroud? I will have a way to remove the panel(s) that cover the conditioner.

How would you secure the rack to the roof?

The RV in question is a 28'5" class C.

[pianotuna]

Hi Cee,

If you are planing to replace the inverter then I'd strongly urge you to consider a 48 volt battery bank. If I were starting from scratch, I would certainly not do 12 volt.

I'd also consider a Victron hybrid. They don't seem to have the issue with GFCI outlets that my Magnum has. I.E. it appears to not be loved by some gfci--but others it works just fine with. It is not a fault in the RV, for if I wire around the Magnum, the gfci does not trip.

BoonHauler wrote:

Cee

PS: I'm looking (in the not too distant future) to change out my MS inverter for an MSH. You and I have a lot in common although I'll stay away from the resistance heating.

[pianotuna]

Hi Mr Wizard,

The mirrors apparently do not count. Nor do awnings. I've thought about hanging panels from the sides. If someone would finally make a truly flexible panel, I would replace the awning in a flash.

MrWizard wrote:

This does not compute
A rolled up awning sticks out further than a folded flat solar panel flat against the side of the RV
Your mirrors stick out further than the awnings
Legal width limits apply to the solid body
Attachments that are under the width of the mirrors are legal

[BoonHauler]

pianotuna wrote:
Hi,

I think it is rear--there is no venting on the top of the shroud.

BoonHauler wrote:
Don:

Does your A/C have rear or top discharge?

My A/C has a top discharge, that's why I'm asking.

If it's not top discharge I'd say go for it. As for the structure to hold the panels, I'd say aluminum channel would work well. I didn't get a chance to look at that light weight super strut mentioned above but that might be a good option as well.

To me the bigger deal is making a good connection to the structural support members in your RV's roof.

Good Luck and post few pics when you get it built. I'm sure there's more than myself that would like to see it.

Cee

PS: I'm looking (in the not too distant future) to change out my MS inverter for an MSH. You and I have a lot in common although I'll stay away from the resistance heating.

[lc0338]

I don't think as long as the panels are parallel with the roof there will be a lot of wind issue. Yes, there will be some gusts upward but my solar generator panels entend above the roof of my truck cab. Of course if Don mounts above the AC unit there will be more distance between panels and roof than my unit. But... I would not put that much weight and wind gust load with attachment to the roof. I would only mount from side of trailer (like the hay rak system). Here is a picture of my solar generator on my truck. There are 2ea 270 watt panels and on my regular cab they completely covered my cab and front edge was out over my hood. On my new truck (crew cab) the leading edge of the panels reach about the front of the cab clicky

[lc0338]

Here is a visual

[MrWizard]

Unfortunate the width prevents me from hanging panels off the sides--I'd be over the legal limit.

This does not compute
A rolled up awning sticks out further than a folded flat solar panel flat against the side of the RV
Your mirrors stick out further than the awnings
Legal width limits apply to the solid body
Attachments that are under the width of the mirrors are legal

[pianotuna]

Hi,

The hay rack looks interesting but is too narrow for my RV.

[pianotuna]

I'm aware of the energy needs of resistance heating and have 3 years of data to draw conclusions from. I want to extend the time before I have to connect to shore power.

I can heat 100% electrically on a single 15 amp circuit in mid October. Adding solar to the mix may extend that a couple of weeks and probably would mean I don't need to use shore power at all in September. Of course, no one can predict the weather.

[pianotuna]

Hi,

I think it is rear--there is no venting on the top of the shroud.

BoonHauler wrote:
Don:

Does your A/C have rear or top discharge?

My A/C has a top discharge, that's why I'm asking.

[Dranoel]

The current necessary for electric heat or A/C would quickly deplete your batteries. You'll need a generator for those.

[BoonHauler]

Don:

Does your A/C have rear or top discharge?

My A/C has a top discharge, that's why I'm asking.

[lc0338]

RoyB wrote:
IC0338 - I was just reading about your hay rack. pretty neat idea... I was thinking about driving down the road and seeing hay straw flying around the roadways wondering where in the heck is all of this coming from haha...

I imagine alot of straw will be blown away from the bales stowed up on top...

Roy Ken

A little may be lost but not too much. If going very far most will cover or put bales of hay in bags to keep them from getting wet. They make zip up bags like you stow your lawn chains in that work well to keep hay in good condition.
In my part of the country 10-20 years ago a lot of chickens were raised. when they were old enough for slaughter trucks with wooden coops stacked up would haul the chickens from farm to processing plant. The old wooden chicken coops were notorious for having broken slats. The chicken catchers didn't care and would load chickens into a broken coop. When the truck left the farm you could find chickens along side the highway all the way from the farm to process plant. Sometimes they would still be alive sitting along side the road but most got splattered by the car following the truck. O'the good ole day's.

[Almot]

A/C is what - 1ft above the roof? If you raise the entire 1200W one foot above the roof, this is scary.

I would put a single small panel directly over the A/C, approximately the footprint of the shroud (2x3ft?) with very little clearance 0.5-0.75" from frame to shroud. And cover the rest of the roof with whatever fits in there, with some shading. Small A/C panel would likely be 12V, so you'll have to include another 12V with similar parameters, in series, - and the rest of array can be 24V.

I realize that the only way to avoid the shading completely is to raise the entire 1200W array above the A/C, but - man, this is scary.

[pianotuna]

Currently 556 amp-hours of surplus acid AGM. In the possible future is switching to LI.

The intent is to be able to run the roof air while drawing some energy from the battery bank. In the fall I'll want to use the power to run resistance heating.

Dimensions:

Length 28' 5", 8.7 m

Height 9' 8", 2.9 m (doesn't include roof air ???)

Width 8' 4", 2.5 m

Wheel base 176”, 14.6', 447 cm 4.47 m

Unfortunate the width prevents me from hanging panels off the sides--I'd be over the legal limit.

corvettekent wrote:
That is a lot of solar, what are you using for a battery bank?

I don't know how tall your RV is but I would keep the panels less than 13' off the ground or 3" - 4" above the AC.