DIY Solar Battery Retro fit

moorman

I have a Solar Edge 16 panel system with optimisers and I am thinking of adding a Sunsynk 5kw AC coupled system
As a retired Electrical Engineer install is not a problem but I am unsure about the setting up of the additional AC Inverter that would be required
As anyone have any knowledge of how easy they are to set up and commission 

Netexporter

There's loads of installation videos on Youtube, some from Sunsynk themselves. A new thing to bear in mind is that that a PAS has recently been published, pertinent to the siting of home batteries, which if ignored could lead to insurance problems down the line. Again, there have been several videos put up in the past week or so explaining the implications.

If you choose a battery that uses the Pylontech protocol (many do) then it should talk nicely to the Sunsynk.

Slinky

What is a PAS please?

Ectophile

Slinky said:

What is a PAS please?

Power Assisted Steering.

Or more likely, PAS 63100:2024, Electrical installations. Protection against fire of battery energy storage systems for use in dwellings. https://knowledge.bsigroup.com/products/electrical-installations-protection-against-fire-of-battery-energy-storage-systems-for-use-in-dwellings-specification?version=standard&tab=overview

Spies

Fairly sure you're not permitted to install in the loft space any longer

Netexporter

Nor bedrooms or escape routes. Outside or in a fire separated garage are encouraged.

theboylard

moorman said:

I have a Solar Edge 16 panel system with optimisers and I am thinking of adding a Sunsynk 5kw AC coupled system
As a retired Electrical Engineer install is not a problem but I am unsure about the setting up of the additional AC Inverter that would be required
As anyone have any knowledge of how easy they are to set up and commission 

Have the same system, just added 5kw Sunsynk ecco inverter on the ac side with 15kWh of batteries.

I can't speak for the electrical side, but the inverter mostly worked out of the box, except the wifi dongle that my installer had to add via a different route as it just wasn't being picked up by the usual install routine.

You might have to split the meter tails and run a dedicated feed for the inverter, via a separate mini consumer unit, makes it all rather neat and self contained.

The ct clamp supplied with the inverter, needs to be as close to the meter as possible, so depending on Sunsynk mounting location, you may need to run a cat 5 cable and just patch it onto the clamp tails.

Heedtheadvice

I do not have Sunsynk but Lux ( with Pylons ) . Set up is a doddle and from above post expect similar.

A few electrical points you might find useful.You no doubt are familiar with wiring regs ( building regs if in England/Wales)  plus new or extended DNO G99 approval need:

High current breaker in consumer  unit and similar cable required between consumer unit and inverter to cope with high short term currents/ voltage drop  plus isolator for inverter. Size no doubt in installation instructions for typical short runs.

DC side should have a high current breaking capacity isolator between inverter and batteries. Not necessarily essential where batts have individual switches but recommended. Likely capacity given in battery install instructions.

I would not install within a domestic property living space- many are - ( but in garage or other outbuilding ) even prior to PAS.

Significant weight in a set of batteries so capable mounting or rack is best.

moorman

Heedtheadvice said:

I do not have Sunsynk but Lux ( with Pylons ) . Set up is a doddle and from above post expect similar.

A few electrical points you might find useful.You no doubt are familiar with wiring regs ( building regs if in England/Wales)  plus new or extended DNO G99 approval need:

High current breaker in consumer  unit and similar cable required between consumer unit and inverter to cope with high short term currents/ voltage drop  plus isolator for inverter. Size no doubt in installation instructions for typical short runs.

DC side should have a high current breaking capacity isolator between inverter and batteries. Not necessarily essential where batts have individual switches but recommended. Likely capacity given in battery install instructions.

I would not install within a domestic property living space- many are - ( but in garage or other outbuilding ) even prior to PAS.

Significant weight in a set of batteries so capable mounting or rack is best.

At present I have system that was installed by an approved installer eight years ago and I receive FIT payments 
The existing inverter is fed in 2.5mm from a 20A MCB through an AC isolater then to my generation meter then through another AC isolater to the inverter 
I have been led to believe that in order to keep my FIT payments an AC coupled inverter and batteries are needed and should be connected AFTER the generation meter.
I therefore assumed that the battery set up could be all stand alone and just connected to the cable that joins the generation meter to the consumer unit MCB

Heedtheadvice

"I have been led to believe that in order to keep my FIT payments an AC coupled inverter and batteries are needed and should be connected AFTER the generation meter.

I therefore assumed that the battery set up could be all stand alone and just connected to the cable that joins the generation meter to the consumer unit MCB "

The system for the FIT generation should not be altered as that is part of the certification and requires to not be amended to continue to be compliant with the scheme. There can be exceptions to fix faults but not otherwise as far as I know.

The battery storage system thus needs to be on the grid side of the FIT system. If not it woukd obviously affect generation meter readings irrespective of any electrical issues. Is that what you mean by 'after'?

Yes the battery system not only can be but needs to be stand alone.

Do not connect into the generation system wiring as the battery storage inverter has it's own requirements for a separate breaker for technical reasons ( capacity and trip/inbalance currents) as does cabling for capacity. That is in addition to reducing trip nuiscance and one of the two systems (generation and storage systems) having a fault causing loss of both of them.

AC side mcb and cable ought to be suprisingly big. My Lux inverter (only 3.6kW nominal) spec is for 40A rcbo and 3-4mm sq cable.

 Your Sunsynk is bigger so it certainly will not work safely using a common mcb and cable with the FIT system. Have a look at the installation requirement from Sunsynk? I do no have access but to see what I mean the lux manual is easily available at https://luxpowertek.com/wp-content/uploads/2023/07/LXP-ACS-3600-user-manual.pdf page 11 shows their AC side.