Advice following a full solar system install

[RobO]

Hi All,

I recently had a full solar system installed and it's been a back and forth with the installer due to some minor issues and observations (with no definitive answers from them) and looking for some clarification and advice please.

Sunsynk 8kW/FreedomWon 10/8 with everything on the essentials side (supposedly).

 

1) Incoming voltage from Eskom usually hovers around 250V. 

Initially, output voltage on the inverter was set to 230V and I noticed when load-shedding kicked in some of my relays (Shelly 1 for example) would stop working.

I then decided to increase the output voltage on the inverter to 240V - this fixed the issue with the relays however it let me to investigate further.

I discovered that when there is no load-shedding, all outlets measure around 250V.

My questions are:

If I have everything on the essential side, should all the outlets see 240V or 250V? My logic would say 240V no?

And if 240V, does that mean there is some "loop" somewhere or the DB not wired correctly?
The DB is not split and from what I understand from the installer, they took the incoming feed back to the inverter, then feed the essentials back to the DB.

The inverter is around 10-12m from the DB.
It's quite a small DB and hard to make out the wiring, without taking everything out.

When load-shedding kicks in, all lights will flicker - probably due to the voltage drop - but should it given its all supposed to be on the essential side?

In case it's relevant I can confirm there is a permanent neutral-earth bonding, whether it's done correctly I could not say but after getting them to add the bonding, I don't have some dim lit LEDs anymore when there is load-shedding.

 

2) I have a booster pump (1.1kW) that supplies the house water from a JoJo tank.

From monitoring I did via a smart relay, it typically peaks to around 1.5kW for a short while, then drops down.

Whenever a tap is turned on or anything else that demands water - all the lights will flicker for a moment.

This does not happen with any other "heavy" loads.

Any pointers what this could be please or is this expected/normal?

 

Many thanks,

Rob

[Bernardf]

From my experience I can confirm the following:

 

1. When Eskom is on, the voltage and frequency output on the essentials side of the inverter will equal that of Eskom.  Only during load shedding will the inverter give out that voltage that you set in the settings.

 

2. Yes it is normal for the lights to dip for an instant when certain loads kick in, especially during load shedding.  I see it when my fridge compressor kicks in, when my washing machine is running, and when my gardener uses the lawnmower during load shedding.

 

3. You shouldn't have a permanent earth-neutral bond, you should have a relay installed that only does the bond when the inverter goes off-grid.  I'm not knowledgeable enough to know what exactly the dangers are though...

[RobO]

Thanks - appreciate the response.

[I84RiS]

On 2023/05/25 at 9:56 AM, RobO said:

Hi All,

I recently had a full solar system installed and it's been a back and forth with the installer due to some minor issues and observations (with no definitive answers from them) and looking for some clarification and advice please.

Sunsynk 8kW/FreedomWon 10/8 with everything on the essentials side (supposedly).

 

1) Incoming voltage from Eskom usually hovers around 250V. 

Initially, output voltage on the inverter was set to 230V and I noticed when load-shedding kicked in some of my relays (Shelly 1 for example) would stop working.

I then decided to increase the output voltage on the inverter to 240V - this fixed the issue with the relays however it let me to investigate further.

I discovered that when there is no load-shedding, all outlets measure around 250V.

My questions are:

If I have everything on the essential side, should all the outlets see 240V or 250V? My logic would say 240V no?

And if 240V, does that mean there is some "loop" somewhere or the DB not wired correctly?
The DB is not split and from what I understand from the installer, they took the incoming feed back to the inverter, then feed the essentials back to the DB.

The inverter is around 10-12m from the DB.
It's quite a small DB and hard to make out the wiring, without taking everything out.

When load-shedding kicks in, all lights will flicker - probably due to the voltage drop - but should it given its all supposed to be on the essential side?

In case it's relevant I can confirm there is a permanent neutral-earth bonding, whether it's done correctly I could not say but after getting them to add the bonding, I don't have some dim lit LEDs anymore when there is load-shedding.

 

2) I have a booster pump (1.1kW) that supplies the house water from a JoJo tank.

From monitoring I did via a smart relay, it typically peaks to around 1.5kW for a short while, then drops down.

Whenever a tap is turned on or anything else that demands water - all the lights will flicker for a moment.

This does not happen with any other "heavy" loads.

Any pointers what this could be please or is this expected/normal?

 

Many thanks,

Rob

Because your inverter is hybrid capable of pushing power back into the grid it has to synchronise with the grid frequency and voltage  (similar to how eskom has to first synchronise a power plant to the grid frequency and voltage before it can connect that plant to the grid). Therefore, while the grid is present the frequency and voltage that the inverter will output will be the same as Eskom.

When the grid is not available it will output whatever you set it to.

[RobO]

Thanks, understood. My thinking was since I have everything on essentials/load it should be outputting whats configured but not the case.