Hi Kirk, There is little to no need to megger test Enphase cabling, and we would not recommend it as part of the normal installation process. Since the microinverters are connected to the cabling in parallel, a microinverter or module failure will not impact the other microinverters/modules on the branch circuit, so it is pretty easy to find where a problem has occurred. If a fault occurs on the DC wiring of the microinverter/module pair, then only that one microinverter will be affected.
If you want to perform an insulation resistance test on an Enphase array, you must ensure that the microinverters are unplugged from the Engage cabling. The surge suppression hardware within the Enphase microinverters will provide a false positive reading if you try to megger test the cabling with the microinverters attached to the cabling. On Mon, Jul 20, 2015 at 2:13 PM, Kirk Herander <[email protected]> wrote: > I recently had to megger (IRT) a Solaredge array to debug an inverter > failure. I didn’t think it possible, but a SE tech told me how to do it > without frying the optimizers. I had to float, then short both pos/neg > string leads and then megger this connection to ground. I’m not sure if it > meggered all the way through to the panels or just through the optimizer > series output. I assume the module input is isolated under this condition. > Anyone have experience IRT’ing Solaredge or other (Enphase, Tigo, etc.) > mod-level electronics? Thanks. > > > > *Kirk Herander* > > *VT Solar, LLC * > > *Proven PV provider since 1991* > > *www.vermontsolarnow.com <http://www.vermontsolarnow.com>* > > dba Vermont Solar Engineering > > NABCEPTM Inaugural Certificant > > VT RE Incentive Program Partner > > 802.863.1202 > > > > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > > -- Cordially, Nick Soleil *Enphase Energy* | Field Applications Engineer office 707-763-4784 <%28707%29%20763.%204784> x7267 cell 07-321-2937 <http://enphase.com/> *Powering What’s Next*™* | *The Enphase Energy Management System <http://ow.ly/HbVS3> <http://community.enphaseenergy.com/> <http://facebook.com/EnphaseEnergy> <http://twitter.com/Enphase> <http://linkedin.com/company/enphase-energy> NABCEP Certified Solar PV Installer #03262011-300 California C10 Licensed Electrician #986315 Texas Master Electrician #284451 <[email protected]> “Don’t get me wrong: I love nuclear energy! It’s just that I prefer fusion to fission. And it just so happens that there’s an enormous fusion reactor safely banked a few million miles from us. It delivers more than we could ever use in just about 8 minutes. And it’s wireless!” - William McDonough
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