Radian 4048a Ac coupled to Enphase. How difficult?

Discussion about adding energy storage to grid-dependent inverters using OutBack Power technology
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Shadow_Storm56
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Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

So if I wanted to ac couple enphase Iq7 inverters to a radian 4048a.... I know how to hook it up and I understand how it works for the most part but how do they communicate? Are you able to see the output stats in optics from the enphase inverters somehow? Or is it essentially they work together but don't directly communicate. Radian can trigger the enphase inverters to turn off by frequency shift and the micros just match the inverters voltage and waveform but they don't really talk.

But then again the radian can use power from the micros to charge so it must somehow know when theres more power available from the micros than what the loads are using..... unless the radian automatically pulls power from the output side of itself when the voltage rises past what it's supposed to until it's at the correct voltage.... that would probably work.

Any experts here on how this works? Raysun? Lol
raysun
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by raysun »

Shadow_Storm56 wrote: Thu Oct 28, 2021 7:36 pm So if I wanted to ac couple enphase Iq7 inverters to a radian 4048a.... I know how to hook it up and I understand how it works for the most part but how do they communicate? Are you able to see the output stats in optics from the enphase inverters somehow? Or is it essentially they work together but don't directly communicate. Radian can trigger the enphase inverters to turn off by frequency shift and the micros just match the inverters voltage and waveform but they don't really talk.

But then again the radian can use power from the micros to charge so it must somehow know when theres more power available from the micros than what the loads are using..... unless the radian automatically pulls power from the output side of itself when the voltage rises past what it's supposed to until it's at the correct voltage.... that would probably work.

Any experts here on how this works? Raysun? Lol
I have remained chaste and purely off-grid so as not to sully my vital bodily fluids with
such aberrations as AC Coupling. 😅😅

There's lots of forum members who are tied to the grid, and can tell you how to safely navigate past the Sirens.
Shadow_Storm56
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

I have remained chaste and purely off-grid so as not to sully my vital bodily fluids with
such aberrations as AC Coupling. 😅😅

There's lots of forum members who are tied to the grid, and can tell you how to safely navigate past the Sirens.


I'd lovee to be off grid... just need a 100-150kw array to put the farm off grid and like.... 30 radian inverters
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Mike Curran
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My RE system: Outback - Garage roof:
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- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, battery backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Mike Curran »

Shadow_Storm56 wrote: Thu Oct 28, 2021 7:36 pm So if I wanted to ac couple enphase Iq7 inverters to a radian 4048a.... I know how to hook it up and I understand how it works for the most part but how do they communicate?
They don't.
Shadow_Storm56 wrote: Thu Oct 28, 2021 7:36 pmAre you able to see the output stats in optics from the enphase inverters somehow?
No.
Shadow_Storm56 wrote: Thu Oct 28, 2021 7:36 pm is it essentially they work together but don't directly communicate. Radian can trigger the enphase inverters to turn off by frequency shift and the micros just match the inverters voltage and waveform but they don't really talk.
Yup.
Shadow_Storm56 wrote: Thu Oct 28, 2021 7:36 pmBut then again the radian can use power from the micros to charge so it must somehow know when theres more power available from the micros than what the loads are using..... unless the radian automatically pulls power from the output side of itself when the voltage rises past what it's supposed to until it's at the correct voltage.... that would probably work.
Any of Outback's inverters (and maybe others' too) will "invert and pass through" any AC applied to their output (load) side, with nary a care about your battery voltage or anything else. That's why AC coupling requires careful control to prevent overcharging your battery.

Edit: If your loads are great enough the AC output from your Enphase inverters will go to them first - path of least resistance.

Edit2: See correction post below.
Last edited by Mike Curran on Fri Oct 29, 2021 3:04 pm, edited 1 time in total.
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-11-10
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
Shadow_Storm56
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

It makes sense atleast, I would probably add an extra relay in addition to the phase shift thing
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by raysun »

Any of Outback's inverters (and maybe others' too) will "invert and pass through" any AC applied to their output (load) side, with nary a care about your battery voltage or anything else.
I've not worked with grid-tied stuff so forgive my ignorance, but its it true any of Outback's inverters can have AC coupled to their AC output?

I know the newer "Grid Interactive" units can support this, but I've never seen it mentioned with the older FX class, except the GVFX/GFX.
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

raysun wrote: Fri Oct 29, 2021 10:35 am
Any of Outback's inverters (and maybe others' too) will "invert and pass through" any AC applied to their output (load) side, with nary a care about your battery voltage or anything else.
I've not worked with grid-tied stuff so forgive my ignorance, but its it true any of Outback's inverters can have AC coupled to their AC output?

I know the newer "Grid Interactive" units can support this, but I've never seen it mentioned with the older FX class, except the GVFX/GFX.
Honestly I feel like it's mostly a firmware thing, even older inverters could probably do it as long as they are able to change the frequency to drop the inverters out if needed
raysun
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Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by raysun »

Firmware has a role, no doubt, but the inverter output circuitry has to be constituted to accept AC input. Not all of them are.
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Mike Curran
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Posts: 2566
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, battery backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Mike Curran »

A correction: If you're off grid, your AC coupled array will try to feed your battery regardless, but as long as your loads are trying to drag the battery voltage down and the array output doesn't exceed your load requirements, your battery should be okay. Regardless, you need the frequency dithering function to protect your battery, and an isolating relay as backup isn't a bad idea.
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-11-10
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
User avatar
Mike Curran
Forum Emperor
Posts: 2566
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied VFXR3524A-01's series stacked, replaced GVFX's (2020)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS. Tigo ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input from 14 Talesun 275W, Enphase M215 microinverters

Battery systems operate in grid-tied, battery backup mode
All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Mike Curran »

raysun wrote: Fri Oct 29, 2021 12:44 pm Firmware has a role, no doubt, but the inverter output circuitry has to be constituted to accept AC input. Not all of them are.
Not that I'm aware of. Believe it or not inverter circuitry does the AC coupling without any special firmware or added components.

Edit: This quote from the Alte store website:
It is important to note that the grid-tie inverter manufacturers have different views and methods regarding AC Coupling. Some grid-tie inverter manufacturers do not support AC Coupling at all, and may VOID the warranty on their inverter/chargers if you do it
But I've never seen an inverter listed as not suitable for AC-coupling applications. AltE lists 4 manufacturers with inverters that work.

https://www.altestore.com/store/info/ac-coupling/
https://smart.tigoenergy.com/p/pZXn7SZQyO45?date=2021-11-10
https://enlighten.enphaseenergy.com/public/systems/Hctc107221
Shadow_Storm56
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

Cool things to know 😀. I think it's a great feature!

Also I'm jelous that you can be off grid there raysun, I'm a farmer with loads that I'm not sure any inverter could run.... unless you can stack like 30 radians together lol.
Make a couple 200 amp services....
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Re: Radian 4048a Ac coupled to Enphase. How difficult?

Post by Shadow_Storm56 »

Mike Curran wrote: Fri Oct 29, 2021 3:06 pm
raysun wrote: Fri Oct 29, 2021 12:44 pm Firmware has a role, no doubt, but the inverter output circuitry has to be constituted to accept AC input. Not all of them are.
Not that I'm aware of. Believe it or not inverter circuitry does the AC coupling without any special firmware or added components.

Edit: This quote from the Alte store website:
It is important to note that the grid-tie inverter manufacturers have different views and methods regarding AC Coupling. Some grid-tie inverter manufacturers do not support AC Coupling at all, and may VOID the warranty on their inverter/chargers if you do it
But I've never seen an inverter listed as not suitable for AC-coupling applications. AltE lists 4 manufacturers with inverters that work.

https://www.altestore.com/store/info/ac-coupling/


I just realized I wouldn't technically need the mate to set the ac coupling mode. You can't use optics to enable the frequency shifting but you can to enable an external relay at a certain battery voltage. So I still can still have the inverter shut off the inverters that way.... or barrow a mate from someone
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