Welcome back to another #SolarTechTalk!
In this episode, Aaron and Kate dive into rapid shutdown, demystifying some of the who, what, and why’s of these important PV system safety requirements. For context and overview, they first meet up with Jason Fisher, Founder of Solar Technical Consulting, Inc. but also, Vice Chair of SEIA’s Codes & Standards Working Group, and a NEC Code Making Panel 4 member. Then A&K chat with Blair Reynolds, Utility Scale Energy Storage Product Manager at SMA America.
As usual, A&K share some recommended readings and links, like BayWa r.e. Global’s Decade That Matters report and a newly posted webinar from InterSolar North America on the recent Texas energy crisis. And finally, we have another Tales from the Roof listener submission segment.
Remember, if you’ve got a memorable, fun, or even scary “Tale from the Roof” to share from your days in the field, call it in! Dial our Solar Tech Talk Storyline at 541-635-2747 and leave us your story on voicemail. We’ll pick the best ones to play on a future show.
— Tom Miller, Marketing Director
In This Episode:
- RAPID ROUNDUP (00:49): Kate gives a shout-out to our parent company BayWa r.e. Global’s climate crisis awareness campaign and Aaron gives two thumbs up to a webinar moderated by Peter Kelly-Detwiler and featuring Amy Heart of Sunrun.
- DEEP DIVE 1 (4:58): A&K visit with solar codes consultant Jason Fisher for a rapid shutdown overview, starting with the safety alphabet soup of PV RS, RSS, RSD, RSE — and a new term, PV HCE (Hazard Control Equipment), with regards to NEC 2017 690.12 and UL 1741. Jason reminds us that these standards are there to protect firefighters during emergency response situations, so they can do their job while having fair expectations of the solar and electrical systems they’ll come across. We get a short history of the conversations between manufacturers and code setters; the philosophy and intent of the codes and how that translates into system design per UL 3741; and the burden on the installer versus the equipment manufacturer.
- DEEP DIVE 2 (35:20): A&K check in with Blair Reynolds of SMA America next to talk all about UL 3741. Blair begins with the NEC 2017 and 2020 code cycles and the two broad categories in terms of rapid shutdown — basically, controlling conductors — with 690.12(B)(1) covering conductors outside of the array boundary, and 690.12(B)(2) covering conductors inside the array boundary. Then Blair explains why systems designers should pay attention to the UL 3741 provisions for PV hazard control arrays and the implications for Module-Level Power Electronics (MLPE). We also get a glimpse at how product lines like SMA’s go through UL 3741 testing, and discuss how “MLPE is not a thing.” Finally, the gang looks at the history of the SunSpec Alliance, and why it’s so important for our solar installation industry, plus the intriguing emergence of midstream circuit interrupters for residential and commercial solar systems designs. Check out the slides Blair shared during our on-screen chat.
- TALES FROM THE ROOF (56:50): Our first-ever Solar Tech Talk caller is Kelly Paduchowski from Flagstaff, AZ. Thanks, Kelly for sharing your story!