Using that logic, wouldn’t the inverters and batteries also be exposed to 300Vdc? And the MX60 would also be at risk for exposing the inverters and batteries to 150Vdc under similar failures?
If that’s the only limiting factor, I’d like to take back a couple AC Coupling arrangements I have made for past Radian expansions. ;-) Maverick Brown Off-Grid Solar Commander since 2006 Maverick Solar Enterprises, Inc. • Solar Commander Remote Power • SunFlow Systems Cathodic Protection [email protected] 512-460-9825 > On Jan 21, 2022, at 11:15 AM, Tuss, Lones <[email protected]> wrote: > > > Hi William > Thank you for taking my call. > I believe the reason we do not recommend mixing the FM100 and the fM60/80 is. > If the FM100 were to short out pv input to output you could expose the 150 > volt rated dc breakers on the > FM60/80 to 300 vdc. > > > > From: RE-wrenches <[email protected]> On Behalf Of > William Miller > Sent: Thursday, January 20, 2022 10:54 PM > To: RE-wrenches <[email protected]> > Subject: [RE-wrenches] Mixing Outback FM100 CC with Fm80 or 60. > > CAUTION: This email originated from outside of the Company. Do not click > links or open attachments unless you recognize the sender and know the > content is safe. > > > Friends: > > I am sure many of you are familiar with the somewhat new Outback FM100 charge > controller. It allows PV input at up to 300 volts and battery feed at up to > 100 amps. It has a built in GFDI fuse, much like the old XW--now branded I > think Conextant-- charge controller. > > Outback recommends against installing an FM 100 in an installation with FM60s > or FM 80s. Here is the tech note that gives that recommendation. Below is > one paragraph from that tech note. > > There is little benefit to mixing an FM100 with an FM60/80. If circumstances > require it, this application > note will explore an option. > > Note the language is pretty dang squirrely. Let’s parse the above paragraph: > > Sentence 1: I submit there may be many scenarios where there is significant > benefit: Like if you already have an FM60/80 and you want to add more PV and > you want to enjoy the benefits of an FM100, such as higher input voltage or > higher output amperage, and not have to fork out an extra $1000 to replace a > working FM60/80. Or you installing more than one PV array, one array nearby > and/or smaller and one further away or larger, and you don’t want to spend > close to $1,000 to charge control the nearer array. > > Sentence 2: They are offering “an option,” not the only option. I believe > there are multiple options. In a mixed installation, the FM100 can rely on > its internal GFDI fuse and the FM60 or 80 can rely on the old familiar GFDI > breaker with the 1 or 0.5 amp pole connected between the negative and > equipment grounding system. Alternatively, Midnite sells a 300 volt rated, > multi-pole GFDI breaker that could be shared by an FM100 and an F60/80. It > says right in the FM100 manual that you can use external GFDI devices (page > 14). > > I am not at all clear as to what problem there is to mixing the two > generations of charge controllers. I reviewed the NEC. There is no > indication that thou shall not mix GFDI styles. > > If anyone has a definitive reason why or why not to mix these models of > Outback charge controllers, I would be most interested. > > Most Sincerely, > > William Miller > > Miller Solar > 17395 Oak Road, Atascadero, CA 93422 > 805-438-5600 > www.millersolar.com > CA Lic. 773985 > > > > > This email and any attachments may contain confidential information that is > intended only for the recipient(s). If you have received this email in error, > please notify the sender and delete it from your system. Any views or > opinions presented in this email are solely those of the author and do not > necessarily represent those of the company or its affiliates. This email does > not constitute an agreement to conduct transactions by electronic means and > does not create any legally binding contract or enforceable obligation in the > absence of a fully signed written contract. The recipient should check this > email and any attachments for viruses. The company accepts no liability for > any loss or damage caused by software viruses. If you are the intended > recipient and you do not wish to receive similar email(s) from us in the > future then please notify the sender. Please consider the environment before > printing. _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > 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/[email protected]/ > 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 >
_______________________________________________ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: [email protected] 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/[email protected]/ 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
