A Forum run by Enthusiasts of MidNite Solar

General Category => General FAQ'S => Topic started by: trumps2000 on October 31, 2014, 04:37:45 PM

Title: MND3RACCPLME AC Coupling and Grid Tie
Post by: trumps2000 on October 31, 2014, 04:37:45 PM
Hi, I'm doing my research and can't seem to find an answer to a question.  Magnum's MS4024PAE inverter looks like the swiss army knife of home power and Midnite's MND3RACCPLME looks awesome.  Now I know the MS4024PAE can send power back to the grid when its up and can charge the batteries through AC coupling(I plan to Enphase microinverters).  I know the MND3RACCPLME uses the ME-RTR and a relay to connect the PV array when the battery voltage drops and disconnect it above a certain voltage.  I don't see how it can sell power back with the grid up and batteries charged though.  The ME-RTR doesn't have an option to activate the relay with power up.  Am I missing something?

Ken
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: Halfcrazy on November 01, 2014, 06:25:25 AM
When the grid is present an internal relay connects the AC out to the AC in on the magnum. The Enphase are connected on the AC out side and the grid is connected on the AC in side so as you see the Enphase are connected directly to the grid when it is present thus "They" sell to the grid not the magnum.
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: trumps2000 on November 01, 2014, 09:39:34 AM
Hi halfcrazy, sorry for posting in the faqs section, I didn't realize it.  :/ feel free to move it.

Going through the ME RTR manual it only turns on the AUX output which turns on the Midnite installed triac to connect the microinverters when battery is low.  There is no option to also turn it on  when grid is present.
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: Halfcrazy on November 01, 2014, 02:24:29 PM
I dont understand? Are you trying to re-purpose one of our prewireds?

We use the Magnum Router to turn off a solid state relay when the battery is to full as an AC coupled Magnum does not regulate the charge voltage when running in AC coupled mode
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: trumps2000 on November 01, 2014, 07:55:15 PM
Quote from: Halfcrazy on November 01, 2014, 02:24:29 PM
I dont understand? Are you trying to re-purpose one of our prewireds?

No just trying to understand how it works.  Its says I can sell power back and charge the batteries off of solar w/o grid.

Quote from: Halfcrazy on November 01, 2014, 02:24:29 PM
We use the Magnum Router to turn off a solid state relay when the battery is to full as an AC coupled Magnum does not regulate the charge voltage when running in AC coupled mode

I understand how this works, but the ME-RTR doesn't switch the AUX relay based on whether or not the grid is present.  So it looks like even if the grid is present if the batteries are charged the triac will disconnect and I won't be able to sell back to the power company.

I'm just wondering what I'm missing.
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: Halfcrazy on November 01, 2014, 08:37:14 PM
The Triac will not disconnect under normal battery charging. it will only disconnect if the battery is slightly over charged.
Title: Re: MND3RACCPLME AC Coupling and Grid Tie
Post by: trumps2000 on November 02, 2014, 06:55:15 PM
Okay I can see that.
Thanks for clearing that up for me!