Has anyone used EMT for the rails to mount solar panels either on a roof, or ground mount ? It is cheap in 10 foot sections here ($6.50 for 1/2"). For less than $200, I can mount 16 or more panels on my roof, including clips, clamps etc. Can somebody tell me why I should NOT use it ? Thanks !
EMT as solar panel rack ?
- Thread starter Area 51
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cs1234
Solar Wizard
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What country are you in? It wouldn't meet any codes in the US.
US. Can you point me to codes that need to be followed ?
Thanks
Depends if you need permits and inspections. Those typically require UL listed equipment.
If not, you can do anything you want. But I’d imagine Area 51 has certain restrictions…
cs1234
Solar Wizard
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The codes would be construction, fire and solar related codes. They are going to vary by state/county/city.
Designing your own mount out of EMC would likely require you to get it approved engineering wise for wind load strength, whether on the roof or the ground. That's the justification the currently commercially available racking has for it's high cost.. they "engineered" it and got it approved.
I don't like the rules one bit, but it's best you be aware there are likely many rules.. especially for roof mounting and grid-tied systems.
If you live in the country, own your home without mortgage and don't care about payout from home owners insurance, then you are free to do what you want until some overzealous county inspector notices it.
zanydroid
Solar Wizard
Hot take: light duty roof racking is not that expensive for the trouble it saves you compared to the other costs of solar and of home ownership overall. The cost is also amortized over a 20-30 year system lifespan...
Especially since you get the engineering, easy AHJ and insurance approval, and a cookie cutter, paint by the numbers instructions on how to install it. It's probably $60-80 per panel, with a long enough portrait mounting run, based on the small order I just placed for it last night.
Especially since you get the engineering, easy AHJ and insurance approval, and a cookie cutter, paint by the numbers instructions on how to install it. It's probably $60-80 per panel, with a long enough portrait mounting run, based on the small order I just placed for it last night.
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Plain and simple: You need to use galvanized strut available everywhere as racking rails. Comes in different depths. If mounting on the roof, use proper roof penetration footers. Then attach your struts to them and the panels to the struts. If ground mounting, use schedule 40 2 inch galvanized pipe wrapped in 10 ml pvc tape where concrete comes in contact with the pipe. Use Hollaender connectors to attach to the posts for the cross rails and galvanized strut for the panel rails. Will meet wind loads.
Thanks -- what company did you use ?
Mike 134
Solar Enthusiast
Look at Iron Ridge racking. UL approved and really easy to install even for me my first time.
Looks like this
EMT product is UL compliant. I am still confused about UL approved, UL compliant, UL certified and UL Listed. So I don't know if it will pass inspection.
Edit: corrected link
EMT product is UL compliant. I am still confused about UL approved, UL compliant, UL certified and UL Listed. So I don't know if it will pass inspection.
Edit: corrected link
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cs1234
Solar Wizard
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It's UL approved / compliant for putting electrical cables into. Not for providing mounting structure for solar panels.
42OhmsPA
What's in a title?
No way would I trust EMT to mount panels, it's not strong enough! You can easily bend 1/2 emt with your bare hands and likely crush it with a good boot stomp... Try that with strut or rail...
Having used UL listed Tamarack on my roof mounts and Strut in the recently finished ground mount I'd recommend either of them...
Pics of both attached. Roof pic has some 1/2 emt in it as well...
Having used UL listed Tamarack on my roof mounts and Strut in the recently finished ground mount I'd recommend either of them...
Pics of both attached. Roof pic has some 1/2 emt in it as well...
Attachments
zanydroid
Solar Wizard
I used Unirac SM light
zanydroid
Solar Wizard
Yup UL listed (or more specifically listed by some NRTL for compliance) is always relative to one or more specific standards.
Another problem with EMT is that it will be a huge labor PITA. All racking systems have evolved labor saving components that are engineered to work properly (electrically and structurally). For EMT those would have to be sorted out manually from a hodgepodge of custom hardware, to a dubious level of effectiveness
zanydroid
Solar Wizard
Oh yeah I know this is a bit overbeating, but I wanted to add that support/secure force required by NEC for EMT is not actually that high.
For instance you can see this on unirac’s product line, which includes both racking and Electrical Balance of System. If you look at how the hardware for EMT clamp flashing compares to rack flashing. The EMT clamp I would call more of a suggestion to stay on the roof.
I believe in the community of people that build structural things out of EMT (like tents and chairs) they use their own joint hardware.
For instance you can see this on unirac’s product line, which includes both racking and Electrical Balance of System. If you look at how the hardware for EMT clamp flashing compares to rack flashing. The EMT clamp I would call more of a suggestion to stay on the roof.
I believe in the community of people that build structural things out of EMT (like tents and chairs) they use their own joint hardware.
Mike 134
Solar Enthusiast
When EMT is used as it's designed (mechanical protection of conductors) it doesn't require a stout mounting clip. Now expect that clip to retain a 3'X 6' solar panel in a 40 MPH wind and you've guaranteed failure.
zanydroid
Solar Wizard
40MPH is peanuts…
Exactly. So if you use EMT for a mechanical use case, you are on the hook to find the appropriate hardware for it… you can’t just grab whatever is called an EMT clip and call it done
Exactly. So if you use EMT for a mechanical use case, you are on the hook to find the appropriate hardware for it… you can’t just grab whatever is called an EMT clip and call it done
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T-486 Ashepoo
New Member
I use 3/4 inch EMT with flexible panels for a portable system. Even with light weight flexible panels, it needs lots of bracing.
flammafeuer
New Member
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I'm looking to use EMT on the ground to support some panels. I tried to find this product, but just found nail straps, which didn't seem like the right thing. Do you have a link?
