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how to correctly position 2 CT Clamps


tfk

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I've had an immersun for years...all good. it uses a ct clamp

I've had solar PV systems for years...all good. one on an inverter and the other on microinverter

I recently installed my first household sunsynk battery and sunsynk inverter. this uses a second CT clamp to sense flow (export)

In total, i have about 8kw of PV and a 3.6kw battery inverter. that is relevant as the PV can exceed the battery inverter's ability to direct charge to the battery

The PV is not wired into the battery inverter and has its own inverter. the PV is on totally separate systems from this sunsync battery and inverter (although in the same house on the same fuse board)

sometimes, like now when it is sunny, the immersun is taking current. However, it's pulling it from the battery which is only at 40% charge.

https://i.redd.it/2u5gocssn99d1.png

I would expect, and am aiming for, the immersun to only take the excess generation that the battery can't handle NOT to deplete the battery

the two ct coils are about 1m apart with the immersun CT coil as close to the grid as possible

it's not possible to wire my existing PV into the new sunsynk inverter.

 

Q: are the coils positioned correctly? (I think so)

Q: Is there any other setting I can make to stop this happening

eg this morning it's weird that the battery started at sunrise on a minimum level of 20%, charged correctly up to 40 ish percent but then started to discharge for the Immersun

THANK YOU AGAIN !!!!

 

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1 hour ago, tfk said:

 
 

I've had an immersun for years...all good. it uses a ct clamp

I've had solar PV systems for years...all good. one on an inverter and the other on microinverter

I recently installed my first household sunsynk battery and sunsynk inverter. this uses a second CT clamp to sense flow (export)

In total, i have about 8kw of PV and a 3.6kw battery inverter. that is relevant as the PV can exceed the battery inverter's ability to direct charge to the battery

The PV is not wired into the battery inverter and has its own inverter. the PV is on totally separate systems from this sunsync battery and inverter (although in the same house on the same fuse board)

sometimes, like now when it is sunny, the immersun is taking current. However, it's pulling it from the battery which is only at 40% charge.

https://i.redd.it/2u5gocssn99d1.png

I would expect, and am aiming for, the immersun to only take the excess generation that the battery can't handle NOT to deplete the battery

the two ct coils are about 1m apart with the immersun CT coil as close to the grid as possible

it's not possible to wire my existing PV into the new sunsynk inverter.

 

Q: are the coils positioned correctly? (I think so)

Q: Is there any other setting I can make to stop this happening

eg this morning it's weird that the battery started at sunrise on a minimum level of 20%, charged correctly up to 40 ish percent but then started to discharge for the Immersun

THANK YOU AGAIN !!!!

 

I think the problem is that the Sunsynk is intelligent enough to control solar power export and battery power export to the grid and non-essential loads, whilst I think your immersun is always considering exported power as solar power. I can't think of anything that's not a makeshift solution, but here are some thoughts, to be cross-checked.

Firstly, if you upgrade to a Sunsynk inverter, my experience is that it makes a lot of your other equipment redundant, ie. just using this all-in-one hybrid can be the simplest solution. Subject to full understanding your total list of equipment.

Which model is it? If it's a 8kW or bigger Sunsynk Hybrid, maybe just to route all your 8kW of panels into the MPPT inputs of the Sunsynk inverter, and you'll have the micro-inverter and the battery inverter spare to adorn your garage shelves.

If you have something smaller like a 5kW Sunsynk or 3.6kW, then transfer as much as possible of the PV panels to the Sunsynk's MPPT inputs, and keep the balance on the microinverter on the AUX/Smart input. That's more efficient when storing DC power to the battery, than to convert AC from the micro-inverter to DC and then back again.

Make sure the immersun is not on the load port, but on the grid port, and put household loads onto the Load port. And if you really want to use "Zero Export to CT" mode with solar sell, then do also set up the Time of Use screen to set the battery power to zero during the daytime when you'd be exporting solar power. I'd move the CT coil of the Immersun to the house-side, and the CT coil of the Sunsynk to the grid side to align the usage meter readings of the Sunsynk with the utility meter.

Another option is to put all the household loads onto the load port of the Sunsynk, then run in "Zero Export to Load" mode with Solar Sell (using Deye terminology). If the pass-through current of the inverter is sufficient for your house. That will eliminate the risk of using the battery to supply the heater on the export-side. However it will create a discrepancy between your utility meter's export readings versus the Sunsynk's measurements.

 

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Wow! sounds like I found someone who knows what they are talking about !!! thank you

*** i'll run your excellent-sounding points by the guy who did the installation ***

I have since communicated with Immersun, who helpfully told me my Immersun is ancient and no longer supported. they included the attached wiring suggestion for a new Immersun model should I upgrade. My guess is that their suggestion might work for my older model as well. It's unusual to me as it suggests using one clamp that spans the inbound and outbound tails (wires) for the Sunsync

https://the5krunner.com/wp-content/uploads/2024/06/Untitled.jpg

 

You say, " I'd move the CT coil of the Immersun to the house-side, and the CT coil of the Sunsynk to the grid side" - this was how the guy did it but i changed it. Surely this would always mean that the Immersun heats up the hot water first and I defnitely don't want to do that in Winter when there wont be much solar.

thank you !!!

--------

I have the 3.6kw inverter under the stairs on the ground floor, it's on a separate fuse/circuit to the Immersun

I'm not currently on any export tariff, I have the old PV tariff and am not interested in selling my surplus to the grid as of today. I don't have a  smart meter as of today. (I know, I know!!!)

I have an old sunnyboy inverter in the loft with 4kw of PV on my house roof.  I guess its feasible I can run these panels to the Sunsync and have planned to do that if the sunnboy ever failed.

my other 4kw are on an outhouse roof that is 10m from the main house. that has a micro inverter for each panel i believe. It's on the same circuit as other electrics in the outhouse. I probably can't change how this is wired.

 

 

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