Page 1 of 1

New Isolated PV- on FLEXpowers for FM100 AFCI

Posted: Fri May 15, 2020 11:33 am
by IanMcCluskey
Happy Friday, forum community!

Sharing this post to spread knowledge about a key update to the PV negative wiring on new FLEXpower Radians with FM100 AFCI charge controllers. We have shipped hundreds of these since they were released earlier this year and installers have contacted us with questions about this change on two occasions so far.

The new FLEXmax 100 AFCI has built in arc fault detection, which works best when both positive and negative PV conductors are isolated. This prevents common mode noise from causing false arc fault trip events. Many OutBack users and installers are accustomed to the PV negative conductors landing on the common negative buss in Radian load centers. However, the new FLEXpower Radians land the PV conductors on separate bussbars within the load center to improve performance and prevent false trips.

We achieved this by using the box lugs on the PV breakers to land the PV positive input. This frees up the aforementioned PV input bussbars to be a separated negative connection for the negative PV input.

Please see the new quickstart guide for reference here: ... 0_qsg.pdf
And in Spanish: ... qsg_es.pdf

Thank you!

Re: New Isolated PV- on FLEXpowers for FM100 AFCI

Posted: Sat May 16, 2020 8:38 am
by Mike Curran
Hey Ian - I'm curious, does the FM100's new built-in AFCI play nice with MLPE's? I only ask because the AFCI circuitry in my Skybox will not, and I'm wondering if Outback has found a way around that... - Mike

Re: New Isolated PV- on FLEXpowers for FM100 AFCI

Posted: Mon May 18, 2020 8:24 am
by IanMcCluskey
Hey Mike! Yes, the FM100 AFCI has an updated arc fault detection system. It is PVRSE listed with IMO FireRaptors, which OutBack sells, and with Tigo's TS4-S and TS4-F devices. We have ongoing tests with Tigo on their other devices, as well.