My understanding of UL3741 PV hazard control is that it is another way
to meet 690 rapid shut down requirements without MLPE. As long as you
can locate the inverter within the array boundary. A nice solution for
commercial where locating the inverter on the roof is fairly easy.
I'm interested in knowing if anyone thinks this could be a solution
(with some tweaking) in residential where locating the inverter on the
roof is typically not an option. Is anyone pushing to either strip the
code of requiring rapid shut down or offering a viable alternative such
as UL3741 has done for commercial?
Personally, I've used Tigo and AP Smart mostly without issues. They seem
to pair well with most all in one inverters. However, I think they are
a huge pain with off grid systems and charge controllers. Best to do
ground mounts and avoid MLPE but that isn't always an option. The only
issue I've had so far is trying to add Tigo TS4-2F to a MidNite Hawks
Bay where I killed the Tigos. My take away was that it not worth the
trouble.
Here are some links for more info on UL3741.
Mayfield Renewables has a course on it.
https://courses.mayfield.energy/offers/ZBxkwokv/checkout?_gl=1*nusd4u*_ga*OTQzNzYwNTU0LjE3MjYxMTI2MTY.*_ga_QYYWLFVGDP*MTczOTgxMzY5Ny4yLjEuMTczOTgxMzg4OC4wLjAuMA..
SMA has a lot of info on it. See SMA link.
https://www.sma-america.com/ul3741
Derek the solarboi YouTube channel "A Bonkers Summer for Solar/UL3741
News and Forcasting" Gives a nice summary of the mess we are now in
with rapid shut down MLPE.
https://www.youtube.com/watch?v=UWUoZg53o80&t=879s
---
Brett Stigile
Owner/Renewable Energy Electrician
503-317-7950
br...@oregonsunwrangler.com
Oregon Sun Wrangler LLC
CCB: 240661
License No: 66LRT
NABCEP PV Installation Professional
certification # PV 100414-008123
On 2025-02-14 18:27, Brett Stigile wrote:
I'm enjoying the discussion on MLPE failures and wondering how do we
move forward away from them. I've seen some info on UL3741 that might
offer the industry a way around or out of using these devices. I've
heard UL3741 has good traction in the commercial space but what about
residential?
There is a YouTube channel by "derek the solarboi" @dereksolarboi who
talks about the problem and potential solution/exit strategy with a UL
listing. Curious if people are following this and think we might be
able to get away from adding MLPE soon.
thanks
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
