| Electronics > Projects, Designs, and Technical Stuff |
| Lots of recalls of solar panel DC disconnect switches |
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| Siwastaja:
Well, to be fair, it's hard to judge from such photos. I don't see any issue in using polycarbonate plastic, if it's of proper quality. I'd like to see a teardown of the actual contacts, and/or a test report before making any judgement. Of course, for expensive not-from-Aliexpress safety switches, I'd expect at least one or two independent test lab markings, but not having them doesn't prove them dangerous, and they haven't been required by law for... two decades now? Yes, we do have wind here, but we also have a new emerging trend of having more and more massive power outages whenever there is some wind, due to a political decision of maximizing the number of trees near the power lines. I can see that distributed power production, such as solar, poses a threat for this wind-interrupted power distribution system, so it's completely logical to make sure the wind affects solar production directly, as well! :clap: |
| soldar:
--- Quote from: Circlotron on May 31, 2019, 01:52:07 pm ---I think the statement is nationalist, not racist. Condemning Asian people rather than the Chinese nation would be racist. --- End quote --- It is still unacceptable. |
| SparkyFX:
I am pretty sure physics work the same in China as it does everywhere else and that you can find properly built equipment in China, in use, time-tested and proofed. No one likes to live with these dangers. Btw. Benedict GmbH is located in Austria, the switch from Daves video was made in Austria, click. In Dave´s video it was quite obvious that weather and exposure to the elements made the enclosure fail, which then led to a failing electrical contact. Electricians are usually not mechanical engineers, roofers or plumbers, but you kind of need these skills to get longevity. If you´d told someone 30 years ago to install a switch in an enclosure on top of the roof... it´d better be a good one. Even if it is rated for the UV and IP65 as stated, there are still temperature swings, expansion, humidity changes and vibration from wind that chew on the plastics and create mechanical stresses, depending on how tight the (metal) screws are torqued down. IMHO the thing either needs a different place or some better mounting, like a piece of sheetmetal above it or be made out of stainless metal in itself with some thought given for the conductors going in and out. But different materials mean different problems. I´ve seen some articles on fires caused in solar installations over the years, which usually creates the pressure on regulators to raise/set minimum requirements. Maybe the switch is required at that place for firefighters to be able to disconnect it and not get additional dangers due to the energy generated by the panels, it would be bad when the safety device itself turns into the source of the hazard. |
| wraper:
--- Quote from: floobydust on May 31, 2019, 06:37:19 pm ---This looks like a cowboy installation, from the Katko website. 390 panels 100kW. The panels and PVM disconnects with just loose wires in a homemade sheet metal box :o Rain is sure to get in. At least there is a ground wire. I hope the panels aren't just sitting on the wood. Unless there is no wind in Finland? --- End quote --- They are obviously weatherproof. I don't say it's necessarily a good design but they should be fine staying outside. |
| soldar:
--- Quote from: SparkyFX on May 31, 2019, 11:00:04 pm --- If you´d told someone 30 years ago to install a switch in an enclosure on top of the roof... it´d better be a good one. --- End quote --- I find it amazing how overbuilt things were in, say, 1950 when Europe had just come out of the war and there was shortages of everything. Now we mount a mains transformer on a pole outside, exposed to the weather, but I see plenty of brick buildings which were made to house transformers. They are tall, narrow buildings so the high voltage wires would go directly in at the top. There must be thousands of those buildings now abandoned. Probably transformers were made more weatherproof and the buildings are no longer necessary. |
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