[RE-wrenches] AC Coupled Enphase

bob at midnitesolar.com bob at midnitesolar.com
Tue Aug 29 15:27:06 PDT 2017


SSRs, especially AC SSRs made from thyrisotrs (scrs and/or triacs)  are 
"leaky" in general

so when turned OFF, can cause a shock....  Maybe not enough to kill you 
but maybe enough

to make you fall off the roof !

I'm not sure why the disconnects aren't good enough which should already 
be in place ?

boB


On 8/29/2017 4:53 AM, Jason Szumlanski wrote:
> My vote would still be to use two single pole relays as suggested 
> previously to kill each leg. That way you build in redundancy and 
> dropping either leg will do the trick. In fact, it sounds like this 
> would be even better than a two pole relay for the redundancy reason.
>
> The other factor is whether you are using NO or NC relays. My engineer 
> requires NO relays in these cases so they would fail in the open 
> position only. I'm not sure how this would work, or if it would work 
> with solid state relays. I have never dug into this. My understanding 
> is that solid state relays fail in the closed condition (shorted). 
> This would preclude their use in a situation where opening the circuit 
> is the preferred failure mode. Maybe someone with some more knowledge 
> in this area can chime in on whether SSRs are a good idea in this 
> scenario.
>
> Jason Szumlanski
>
>
> On Mon, Aug 28, 2017 at 10:19 PM, Nick Soleil 
> <nsoleil at enphaseenergy.com <mailto:nsoleil at enphaseenergy.com>> wrote:
>
>     The one-pole relay will work for de-energizing any of the Enphase
>     microinverters.
>
>     Nick Soleil
>     Field Application Engineer
>     Enphase Energy
>     Cell: 707-321-2937 <tel:%28707%29%20321-2937>
>
>     On Aug 28, 2017, at 6:03 PM, Drake
>     <drake.chamberlin at redwoodalliance.org
>     <mailto:drake.chamberlin at redwoodalliance.org>> wrote:
>
>>     Hi Nick,
>>
>>     I should mention that the inverters being AC coupled are M-250s,
>>     not the new IQ series. Would that make any difference?
>>
>>     Thanks,
>>
>>
>>     Drake
>>
>>
>>     At 03:12 PM 8/28/2017, Drake wrote:
>>>     Hi Nick,
>>>
>>>
>>>     At 11:20 AM 8/28/2017, you wrote:
>>>>     Content-Language: en-US
>>>>     Content-Type: multipart/alternative;
>>>>             
>>>>     boundary="_000_56449940CA694DDAABB811FCC45A2070enphaseenergycom_"
>>>>
>>>>     You can use a one-pole relay.  We show one-pole switching in
>>>>     our zero-export, self-consumption doc for PEL applications.
>>>>
>>>>     Nick Soleil
>>>>     Field Application Engineer
>>>>     Enphase Energy
>>>>     Cell: 707-321-2937 <tel:%28707%29%20321-2937>
>>>>
>>>>     On Aug 28, 2017, at 6:44 AM, Drake
>>>>     <drake.chamberlin at redwoodalliance.org
>>>>     <mailto:drake.chamberlin at redwoodalliance.org>> wrote:
>>>>
>>>>>     Hello Wrenches,
>>>>>
>>>>>     I am going to AC couple some Enphase inverters and found some
>>>>>     really nice solid state, single pole relays to control them
>>>>>     with. Enphase says I must use 2 pole relays for the control
>>>>>     current even though the disconnects will turn off all power
>>>>>     for maintenance.
>>>>>
>>>>>     Enphase claims that the inverters will not shut down reliably
>>>>>     with only one line opened. This does not make sense to me in
>>>>>     view of UL 1741. Is Enphase correct in their claim, or are
>>>>>     there other reasons that both poles need to be opened
>>>>>
>>>>>     I want to use the solid state relays because the coil voltage
>>>>>     is between 3 and 32 volts. This would avoid the need to add
>>>>>     voltage dropping series resistors to protect the coil for
>>>>>     higher battery voltages.
>>>>>
>>>>>     Alternatively, does anyone know of reasonably priced, 2 pole
>>>>>     solid state relays?
>>>>>
>>>>>     Thanks,
>>>>>
>>>>>     Drake
>>>>>
>>>>>
>>>>>     Drake Chamberlin
>>>>>     /Athens Electric LLC
>>>>>     OH License 44810
>>>>>     CO License 3773
>>>>>     NABCEP Certified Solar PV
>>>>>     740-448-7328 <tel:%28740%29%20448-7328>
>>>>>
>>>>>     /_______________________________________________
>>>>>     List sponsored by Redwood Alliance
>>>>>
>>>>>     List Address: RE-wrenches at lists.re-wrenches.org
>>>>>     <mailto:RE-wrenches at lists.re-wrenches.org>
>>>>>
>>>>>     Change listserver email address & settings:
>>>>>     http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>>>     <https://mailtrack.io/trace/link/3edab27b5ab293b8ed7e9b72f6b21719374c3d42?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=4d8b59c3f4041e3e>
>>>>>
>>>>>
>>>>>     List-Archive:
>>>>>     http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>>>     <https://mailtrack.io/trace/link/46525d1ae98ac2c9b206af627e181a5e7abef1f9?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=f1379328237c52bb>
>>>>>
>>>>>
>>>>>     List rules & etiquette:
>>>>>     www.re-wrenches.org/etiquette.htm
>>>>>     <https://mailtrack.io/trace/link/37c2fa3cce2cec32c9af29b35805b1166887102d?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=f5a9d67705ba6495>
>>>>>
>>>>>     Check out or update participant bios:
>>>>>     www.members.re-wrenches.org
>>>>>     <https://mailtrack.io/trace/link/42b8962882456a240060cea7f870a550cf549bc6?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=8682c7a34db623bd>
>>>>     _______________________________________________
>>>>     List sponsored by Redwood Alliance
>>>>
>>>>     List Address: RE-wrenches at lists.re-wrenches.org
>>>>     <mailto:RE-wrenches at lists.re-wrenches.org>
>>>>
>>>>     Change listserver email address & settings:
>>>>     http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>>     <https://mailtrack.io/trace/link/3edab27b5ab293b8ed7e9b72f6b21719374c3d42?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=4d8b59c3f4041e3e>
>>>>
>>>>
>>>>     List-Archive:
>>>>     http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>>     <https://mailtrack.io/trace/link/46525d1ae98ac2c9b206af627e181a5e7abef1f9?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=f1379328237c52bb>
>>>>
>>>>
>>>>     List rules & etiquette:
>>>>     www.re-wrenches.org/etiquette.htm
>>>>     <https://mailtrack.io/trace/link/37c2fa3cce2cec32c9af29b35805b1166887102d?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=f5a9d67705ba6495>
>>>>
>>>>     Check out or update participant bios:
>>>>     www.members.re-wrenches.org
>>>>     <https://mailtrack.io/trace/link/9b840d0d9b3573fe10be9ca23650f9910436d5fb?url=http%3A%2F%2Fwww.members.re-wrenches.org%2F&userId=1613865&signature=125e41a41f5138ad>
>>>     _______________________________________________
>>>     List sponsored by Redwood Alliance
>>>
>>>     List Address: RE-wrenches at lists.re-wrenches.org
>>>     <mailto:RE-wrenches at lists.re-wrenches.org>
>>>
>>>     Change listserver email address & settings:
>>>     http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>     <https://mailtrack.io/trace/link/3edab27b5ab293b8ed7e9b72f6b21719374c3d42?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=4d8b59c3f4041e3e>
>>>
>>>
>>>     List-Archive:
>>>     http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>>     <https://mailtrack.io/trace/link/46525d1ae98ac2c9b206af627e181a5e7abef1f9?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=f1379328237c52bb>
>>>
>>>
>>>     List rules & etiquette:
>>>     www.re-wrenches.org/etiquette.htm
>>>     <https://mailtrack.io/trace/link/37c2fa3cce2cec32c9af29b35805b1166887102d?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=f5a9d67705ba6495>
>>>
>>>     Check out or update participant bios:
>>>     www.members.re-wrenches.org
>>>     <https://mailtrack.io/trace/link/9b840d0d9b3573fe10be9ca23650f9910436d5fb?url=http%3A%2F%2Fwww.members.re-wrenches.org%2F&userId=1613865&signature=125e41a41f5138ad>
>>     _______________________________________________
>>     List sponsored by Redwood Alliance
>>
>>     List Address: RE-wrenches at lists.re-wrenches.org
>>     <mailto:RE-wrenches at lists.re-wrenches.org>
>>
>>     Change listserver email address & settings:
>>     http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>     <https://mailtrack.io/trace/link/3edab27b5ab293b8ed7e9b72f6b21719374c3d42?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=4d8b59c3f4041e3e>
>>
>>     List-Archive:
>>     http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>>     <https://mailtrack.io/trace/link/46525d1ae98ac2c9b206af627e181a5e7abef1f9?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=f1379328237c52bb>
>>
>>     List rules & etiquette:
>>     www.re-wrenches.org/etiquette.htm
>>     <https://mailtrack.io/trace/link/e5dd443e106ab9262a64531e245e33cacc6439c3?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=1ff02acb7afaa5ce>
>>
>>     Check out or update participant bios:
>>     www.members.re-wrenches.org
>>     <https://mailtrack.io/trace/link/df1a46cc62f80e77abb320b6b58d2daa1df33313?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=5658938ab50f2b2d>
>>
>
>     _______________________________________________
>     List sponsored by Redwood Alliance
>
>     List Address: RE-wrenches at lists.re-wrenches.org
>     <mailto:RE-wrenches at lists.re-wrenches.org>
>
>     Change listserver email address & settings:
>     http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>     <https://mailtrack.io/trace/link/d637b44281f438904170f585d45de0c029d858d0?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&userId=1613865&signature=4e891bb2cdab5fbc>
>
>     List-Archive:
>     http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>     <https://mailtrack.io/trace/link/e6c3b50ab784871396cf8aa61952a354fd078c8c?url=http%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2Fmaillist.html&userId=1613865&signature=5c6459243bdea642>
>
>     List rules & etiquette:
>     www.re-wrenches.org/etiquette.htm
>     <https://mailtrack.io/trace/link/e5dd443e106ab9262a64531e245e33cacc6439c3?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&userId=1613865&signature=1ff02acb7afaa5ce>
>
>     Check out or update participant bios:
>     www.members.re-wrenches.org
>     <https://mailtrack.io/trace/link/df1a46cc62f80e77abb320b6b58d2daa1df33313?url=http%3A%2F%2Fwww.members.re-wrenches.org&userId=1613865&signature=5658938ab50f2b2d>
>
>
>
>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> www.members.re-wrenches.org
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20170829/a6f98d38/attachment-0002.html>


More information about the RE-wrenches mailing list