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Grid Zero question

Posted: Thu Jan 06, 2022 12:36 pm
by jmktexas
I have 6-7 year old GVFX 3648 and I've never had any problems with it. I usually just sell excess to grid but I was wondering if the GVFX supports grid zero. It is not an option on this mate3 but I haven't updated any of the firmware in 6 years so I don't know if that's the problem. I hate to fix something that's been working so I haven't messed with any of the updates.
It has occurred to me the GVFX doesn't support grid zero. I asked Outback a couple of weeks ago but they haven't responded yet. So I thought I'd ask the forum.

Re: Grid Zero question

Posted: Thu Jan 06, 2022 1:34 pm
by raysun
The GVFX is OB's original grid interactive inverter. It has limited modes, and Grid Zero is a much later introduction.

If its been in operation for 6-7 years, that's great, and par for the course of OB kit. The model was discontinued a lot of years ago. Thats a vintage inverter. The firmware cannot be field-upgraded.

The basic guts of the inverter architecture are essentially the same. Hats off to the original designers. The brains evolve however, also as designed. The latest VFXR-A models have a lot of smarts, like 7 Inverter Modes and Lithium battery support.

Re: Grid Zero question

Posted: Thu Jan 06, 2022 2:27 pm
by jmktexas
That’s sort of what I guessed. Just wanted to make sure. I’m in the process of upgrading to FPR 8048 radian and I was going to try grid zero with it.

Will the radian and gvfx play nice together with one grid tie and the other grid zero or will they fight? I’m probably going to end up with two separate essential load panels.

Thanks for your reply

Re: Grid Zero question

Posted: Thu Jan 06, 2022 2:50 pm
by raysun
I'd imagine the system will throw a lot of errors if both are active on the same Hub.

Is that much output really needed? Will the battery / charging systems handle that much load?

Re: Grid Zero question

Posted: Thu Jan 06, 2022 3:33 pm
by jmktexas
Well….I’ve use the gvfx all this time for backup for all my 110 loads. My plan is to use the radian for as much as is reasonably possible for 220 loads. It will operate totally separately from gvfx. Only thing they will share is grid input. I will have separate load centers, panels, charge controller, inverter, mate, batteries. . . . . .
As I understand it, fpr8048A-300 comes with all that factory wired.
I was hoping to be able to continue using the gvfx somehow.

Here in Texas, little has been built for energy efficiency - but that’s a whole different discussion.

Re: Grid Zero question

Posted: Thu Jan 06, 2022 4:10 pm
by raysun
Separate systems is perfectly fine, of course.

Also, I'm sure you know the Radian (two 4kW modules in the chassis = 8kW) is standard North American 240V split phase, so they output L1<-120V->NEUTRAL<-120V->L2.
240V is L1<->L2. 120V on each L1<->NEUTRAL and NEUTRAL<->L2. In case both 240V and 120V are required from the Radian.

Re: Grid Zero question

Posted: Thu Jan 06, 2022 4:27 pm
by jmktexas
Ah yes I may have had typo there.
I assumed as separate systems they would work but you what assume means. Still I’m going to be interested in how/if the gvfx sees radian as grid when I lose the real grid(happens more often than you might think).

Re: Grid Zero question

Posted: Thu Jan 06, 2022 4:34 pm
by raysun
Still I’m going to be interested in how/if the gvfx sees radian as grid when I lose the real grid(
Way above my pay grade. (I'm strictly off-grid.)

Re: Grid Zero question

Posted: Thu Jan 06, 2022 5:36 pm
by Mike Curran
Still I’m going to be interested in how/if the gvfx sees radian as grid when I lose the real grid
It sounds like you're connecting the GVFX grid input terminals to the Radian's output, so that during a grid outage your GVFX will think it's still connected to "grid". If that's what you're doing, it's called AC coupling. Your Radian is perfectly capable of handling this connection. Note that your GVFX will be charging your Radian's battery in this setup, as well as its own, but the GVFX battery will have priority as long as its own charge parameters have not been met. (Normally in a grid-tied system with an FNDC you cannot "sell" to [your Radian's] grid until charge parameters are met.) If your Radian's battery gets fully charged in this setup, the Radian will try to get your GVFX to disconnect by raising its output frequency, which the GVFX will see as a bad AC input and disconnect itself.

Unusual setup, overly complex IMO. Good luck.

Edit: If it were me and I needed two battery-based systems I would keep them totally separate.

Re: Grid Zero question

Posted: Thu Jan 06, 2022 7:43 pm
by jmktexas
I haven’t set anything up yet so I could do it like that. I just need to wrap my head around the wiring.

Thanks for your help

Re: Grid Zero question

Posted: Fri Jan 07, 2022 8:23 am
by ralphday224
I couldn't wrap my head around Grid zero and mini grid. I've been running HBX since commissioning my system (Mate3, VFXR3648). I tried GZ and MG and low battery grid transfer and couldn't get the GZ and MG to work, the LBX would still have grid through to the loads (as I think it's supposed to). Does LBX just synch to grid (voltages same on grid outlet and "inverted" outlets) or does it actually use grid to power the loads.

Went back to HBX since it's tried and proven for me.