Add Panels on Steel Tech Shed

jasgrif11 · 14-04-2023 09:36AM #1

Hi all,

I have a Steel Tech Shed arriving at the end of the month and was thinking of extending my ground mount by installing a few panels on the south-facing roof of the SteelTech.

Have any of you installed panels on a SteelTech? If so, are there special fixings? Anything to watch out for?

Thanks

graememk · 14-04-2023 11:12AM

Quick Google, it looks like it's the standard trapezoid steel roof?

Rensol do a rail that directly attaches to the roof with self threading screws, metasol I think it's called.

There's a k2 micro rail too, with the same idea.

bunderoon · 14-04-2023 01:04PM

Don't think the steeltech shed roofs are designed to be load bearing. Could also void your warranty with them.

Each panel is ~20Kg or more

Gerry · 14-04-2023 01:35PM

ah, wouldnt worry.

jasgrif11 · 14-04-2023 08:59PM

The K2 micro rail looks to be the job. I'll wait until the shed is in and then see if I can get 2 or 3 panels on. Will update here

unkel · 15-04-2023 03:23PM

K2 micro rails are the easiest install ever. The self tapping screws have a built in rubber washer that ensures water proofing. This is also the cheapest possible way to mount panels. So not only DIY friendly, but also giving the shortest possible pay back time.

Gerry · 15-04-2023 11:38PM

made a start on this today. van der valk fixings.

10-10-20 · 16-04-2023 12:13AM

A well timed thread. I was planning similar but didn't get as far as looking at rails, except I spotted this on watuneed.

https://www.wattuneed.com/en/mounting-systems/1579-steel-bin-roof-mounting-kit-0712971129481.html#/clamps-40_mm/panels_quantity_per_row-2_panels_in_portrait

I presume that these shed based systems will be on microinverters?

jasgrif11 · 16-04-2023 07:37AM

I’m planning to extend my existing South facing string, so all going back to my grid tied inverter

Plebian · 16-04-2023 07:49AM

For sound proofing and some extra insulation against moisture, I put tecsound heavy insulation on the ceiling of my steeltech basic spec office shed and it's 7kg/m2. No issues with it since. ( https://www.soundinsulation.ie/product/tecsound-sy70-for-stud-walls/ )

I was thinking about this too... and the skeletal structure looks fairly strong so I doubt it'd cause issue with the 20kg of the panel attached to that?What about the panels causing a racket and noise with the rain, or possible leaks?

16-04-2023 12:00PM

I just used the Van der valk standard rail and fixed it to the main frame of the shed with self tappers, fitted two 90 degree brackets to the gable ends of each panel for extra wind protection.

Install done last August and no issues so far.

Fitted four on a four port microinverter.

Jonathan · 16-04-2023 12:19PM

https://www.boards.ie/discussion/comment/120483683#Comment_120483683

Tell us more about that interesting looking structure to the left of that photo. Possibly interested in doing something similar.

16-04-2023 01:27PM

https://www.boards.ie/discussion/comment/120483727#Comment_120483727

Just built a frame for another 6 panels with some metal sheeting underneath for shelter from sun/rain. Another 2 four port microinverters under those panels.

bullit_dodger · 16-04-2023 04:29PM

https://www.boards.ie/discussion/comment/120483918#Comment_120483918

I like that - respect.

Gerry · 16-04-2023 09:32PM

Bit of finagling around with fixings and I've got a mounting system that I'm happy with. mixture of the wood screws and m10 threaded bar.

new technology here.

Need to do same on the ridge and sorted.

bullit_dodger · 16-04-2023 09:50PM

Good stuff. Make sure that there's no water ingress onto that wood. Last thing you want is over a few years for the wood to rot and then it becomes brittle and a good wind takes the lot away. Bolts are better (if that's an option)

Gerry · 16-04-2023 10:02PM

nah theres no water getting in there. The fixings include a rubber seal. Also Ive drilled the lower part of the box section such that the screw is engaged in the steel. so its like an m9 self tapper. belt and braces. And finally that "nut" is hardwood.

bullit_dodger · 16-04-2023 10:49PM

https://www.boards.ie/discussion/comment/120485760#Comment_120485760

Sounds like you got it covered. I was also paranoid with my own DIY installation for water egress. Like you my shed roof is very accessible and I don't mind popping up to check it, but at the same time want to get decades out of it.

graememk · 16-04-2023 11:02PM

https://www.boards.ie/discussion/comment/120485929#Comment_120485929

And my agri sheds an odd leak doesn't matter at all, there's an open ridge and the steel is "space sheeted" (no overlap and a screw thick space between the sheets)

Gerry · 17-04-2023 07:22AM

I am as happens wondering if I should open more ventilation along with adding the panels. it seems the only current ventilation is at the eaves, some at the ridge would be better as its an oven in the summer. but probably best putting a vent in each gable end.

bullit_dodger · 17-04-2023 09:16AM

https://www.boards.ie/discussion/comment/120486297#Comment_120486297

If anything the panels will cool the shed as there'll be a few centimeters between the panel and the steel roof where previously the sun would have been beating down on the roof directly.

I'd leave it and see how you get on.

10-10-20 · 17-04-2023 11:37AM

I hate to bring it up, but how are people dealing with earthing, or more precisely equipotential bonding, on sheds with micro-inverters? I'm not an electrician, but I'd be of the opinion that the shed needs to be bonded to the CPC/earth on the AC feed cable, but that there may be instances where the shed requires a local earth.

The risks of getting this wrong and having a cable fault and short to the shed or to the mounting hardware far outweigh the gains, hence I'm asking.

bullit_dodger · 17-04-2023 11:59AM

I used the AC earth. Not 100% it's right/wrong. I did look and was not able to find a definitive answer. I even asked one of the sparks who was back working on my main installation and he was unsure if it needed a seperate earth.

I mean earth is earth, in theory it shouldn't matter if you sink a DC earthing rod into the ground or go back via the CU to the house's AC earth. What I was a little unsure about is if there was potentially (for example) some earth leakage detection going on, would this cause an issue....but it's beyond my knowledge. I'm relatively comfortable with using the house's AC, but if anyone knows better I'd very much like to know too.

slave1 · 17-04-2023 01:38PM

https://www.boards.ie/discussion/comment/120483918#Comment_120483918

FYI there are slips available that you can attach to the "gaps" between the panels which eliminate the need for a sub structure as the panels themselves are now a full shelter. I have not used them myself but seen on YT

17-04-2023 06:40PM

https://www.boards.ie/discussion/comment/120487416#Comment_120487416

Thanks, didn't know that, Mrs wanted all the cables and bits hidden, so might not have gone that way had I known.

17-04-2023 06:50PM

https://www.boards.ie/discussion/comment/120487004#Comment_120487004

I ran 6 sq swa cable out to the microinverters, used that to earth the frame of the shed. Between the swa and the 6 sq earth it should be more than adequate. Having a low enough earth loop impedance is the critical factor here so your overcurrent device will trip in the required time in the event of a fault. Each panel is bonded, as is the metal sheeting under the timber frame. The mounting rails should also be connected.

Gerry · 17-04-2023 09:05PM

https://www.boards.ie/discussion/comment/120488715#Comment_120488715

sorry but I've not quite made sense of this. so the shed frame is earthed to what then.. to a separate grounding rod, or to the house?

10-10-20 · 17-04-2023 09:43PM

https://www.boards.ie/discussion/comment/120489269#Comment_120489269

Well, this is part of my question, specifically for microinverters.

I think that the metal of the shed is considered to be an extraneous-conductive-part and needs to be earthed (ie, parts of it connected with 10mm2 earthing cable), but that the metal support frame for the solar panels, where the microinverters are installed to and the AC cable clipped to, would need to be bonded back to the SWA and CPC.

Gerry · 17-04-2023 10:05PM

So then the metal frame for the panels by being mounted to the shed is bonded to a separate shed earth AND to the SWA. I guess this is back to your point about equipotential bonding.

Gerry · 17-04-2023 10:25PM

I had a look at the specific microinverters I am using (enphase m215). They don't have a dedicated ground attachment, and their product sheet says they have integrated ground.. so do not need separate grounding. They've ground fault protection also. They do say that by code, the panels and rails should still be grounded, I think the same applies whether microinverters are used or not. So, I'll stick with the earth in the ac cable for the inverters , and add a separate ground for the shed frame.

bullit_dodger · 17-04-2023 10:51PM

The one thing that did occur to me when installing my own panels with micro-inverters was if one of the panels got hit by lightening (unlikely, but you have to think of these things I guess) is that I could then be feeding that lighting energy into my consumer unit as I used the regular AC earth, with all the goodness that entails. But this isn't any different from the grounding that was done on the main installation's panels on the main roof if that was hit by lightening that would go the same route.

I read a lot on it, and was more confused by some of the explanations given. For me each micro-inverter has an earth going into it from the AC side, and at least on the Hoymiles microinverters there's an earth screw in externally on the micro-inverter case which I used to connect to the panels frame. (are others the same?)

I wasn't using rails as they were connected to wood, but I guess the frame itself could get energised hence why I earthed it.

Add Panels on Steel Tech Shed

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