Solis S5-EH1P6K-L no grid detected

[Ranging6880]

Hi,

First time poster, but been lurking/reading for quite some time.

I've installed a battery system (PV to follow), but cannot get the inverter to detect the grid. Installation is as in the attached sketch.

If transfer is set to (2), and Rotary Isolator to "Off" then CU and loads all receive power as expected. If the transfer switch is set to (1) and Rotary Isolator to "On", then the inverter will supply the CU and loads from the battery. However, on this setting, the inverter also reports "Grid not detected".

Inverter recognises the Arcel meter installed (on Live between DNO cutout and meter) and reports RS485 communication with the meter OK.

Transfer switch supplies Inverter into AC-Grid; AC-Backup goes to rotary isolator and then on to the CU.

Can anyone help me troubleshoot this?
Thank you

 

[SeaGal]

Welcome!

Can you explain what you are trying to achieve exactly? If powering the CU when there is a grid outage, then it would be expected for the Solis to have no AC-Grid input.

I'm not a sparky but IME, the important points for using the Solis's AC-Backup port are:-
- you must never connect the AC-Backup to the AC-grid connection
- the Solis will only provide max of 5kW from its AC-Backup port, so only suitable for critical loads and no high power inductive loads
- you will need to consider separate earthing arrangements for the critical loads circuit if your existing setup uses TN-C-S earthing

 

[Ranging6880]

Thanks @SeaGal

Goal here is to have a simple energy storage system for timeshifting consumption - buy off-peak cheaply, fill up the battery and EV, and use the battery power throughout the day. So for 20 hours a day, supply is from battery to CU via inverter; for 4 hours a day, supply is from grid to battery via CU, and from grid to EV (via separate CU).

The transfer switch and rotary isolator are there so that the inverter and battery can be completely isolated from the CU while allowing the loads to remain live, supplied from grid directly.

you must never connect the AC-Backup to the AC-grid connection

i.e. AC-Backup must never receive incoming AC, yes? In this scheme, rotary isolator to be "off" before Transfer Switch takes inter out of the supply path?

Re earthing, I have a TT setup for the AC-Backup loads PE.

 

[SeaGal]

OK, that makes sense. But, as the Solis is grid-tied, you don't need to do any switching or even use the AC-backup port to achieve what you describe.

In 'self use' mode, the Solis will supply as much power as it can from the battery via the AC-grid port to power the house load. For the EH1P 6kW, that is 5kW of battery power (the 6kW value only applies when you have PV input too).

Your Acrel meter will monitor grid usage and prevent battery power going to grid.

If you draw more than 5kW (e.g. kettle on when dishwasher is heating) the battery will provide 5kW and the rest will come from the grid.

Once the battery is discharged down to the overdischarge SOC % value, the Solis will stop using it to power the house and your house loads will be powered exclusively from the grid.

Although I have PV input too, that's pretty much how our system works over the winter dark months - i.e. charge up at cheap night rate and use battery in day and evening to avoid using any peak rate electricity.

 

[Ranging6880]

Thanks, that's reassuring.

I wasn't aware this inverter was grid tied - in fact I was actively trying to avoid that so we can use our battery if there is a power cut (very low risk where we are, but with young children and electric ASHP for heating and hot water...). Another problem for another day, never mind!

If I understand you correctly though, I just need to connect "Grid" via the rotary isolator to the CU, and nothing on "Backup"?

 

[SeaGal]

If I understand you correctly though, I just need to connect "Grid" via the rotary isolator to the CU, and nothing on "Backup"?

Yep. Give a shout if you have any further questions - there are quite a few of us on here from the UK/Europe with Solis S5 RHI or EH1P inverters.

 

[SeaGal]

P.S. here's a good guide for setting up the night charging correctly...

Solis Hybrid Inverter: charging from the grid

How to configure your Solis Hybrid Inverter to charge from the grid on schedule.

blog.jonsdocs.org.uk

 

[Ranging6880]

Yep. Give a shout if you have any further questions - there are quite a few of us on here from the UK/Europe with Solis S5 RHI or EH1P inverters.

Thanks. I just did this, but still no dice. The inverter doesn't turn on with grid power alone, only when battery is also powered on does the inverter start. AC-BACKUP is disconnected, AC-GRID connects to rotary isolator then onwards to a Henley block. That block has two additional pairs in it, one to the 100A isolator (after the meter), and one to the CU.

At this link you can see the whole startup sequence with grid power to inverter, and battery turned on at 00:00. At 00:10 you can see that the inverter does display incoming power from the grid, but at 00:17 it has gone. This seems to be the same instant at which the "Operating" green light starts, and the "Alarm" for NO GRID begins.

Any clues to deciphering this behaviour?

 

[SeaGal]

The inverter doesn't turn on with grid power alone, only when battery is also powered on does the inverter start.

TADTS The Solis S5's internal electronics are powered by DC, not AC. If there is no DC (i.e. no PV input or no battery power) nothing will run. Which makes sense as if there is no DC there is nothing the inverter can invert!

Scared the life out of me when I first tried to fire it up - thought I had a duff - but confirmed by Solis tech docs; see my post here and the link I posted immediately below it..

Solis RHI 5kw + Pylontech US500 not stopping discharge at defined SOC

OK, not sure I understand what the standby mode is or how it is triggered. We don't use the Solis app, so don;t have those coloured icons to look at, sorry.

diysolarforum.com

As for the start up (or lack of it), I'll mull that over. The screen is reporting CAN-OK, and battery shows 35%, but for some reason it shuts down soon after status says 'no-GRID'.

The only time mine does that is if there is a battery comms failure - e.g. by unplugging the CAN bus cable.

It would be interesting to see what alarm it has logged, but I doubt you'll have time to navigate to the alarm screen in time to see that, before it shuts down. (edited to add, I guess it's just no-grid, so probably not that useful)

 

[SeaGal]

OK, I have some ideas...

What happens if you fire it up and grid is connected? Does it stay up?

Assuming it does, then check that Backup supply is enabled - I'm wondering if the only reason it shuts down if there is battery but no grid is if backup supply is disabled. That would make sense as there is nothing it can usefully do if the backup port is disabled and there is not grid to grid-tie to?

 

[Solar Guppy]

Solis inverters and Hybrids ( and most all other brands ), other than the new USA S6 Hybrid, require DC power to operate, with Solar or Battery. If neither are present, the unit has no power source.

I have a pair of 5G's that one is has a battery the other not and the grid-tie unit powers off each night

I now have a new S6 US version and it will power up on just grid power, but that won't help the OP but in my view is an improvement.

The reason the older units were designed to not use AC was to have no power consumption at night ( tare loss ) and improve the effective net energy harvest from solar. If one get a Hybrid, without the battery, its just a GT inverter effectively

 

[SeaGal]

@Solar Guppy yes, I agree, but any idea why his powers up and then turns off, despite the screen showing CAN OK and battery at 35% - do you think my wild guess (re backup not being enabled) is a possibility?

 

[Ranging6880]

@SeaGal @Solar Guppy Thanks both. Requiring DC power to operate makes a lot of sense, now I apply a brain to it

Just to clarify, the unit powers up fine with DC and stays on - but doesn't push any battery power into the CU. I know it can (i.e. isn't defective), as I got it to do so quite contentedly.

I can't work out though why it detects grid in startup, but then once "operational", decides it can't detect the grid and spits out a NO-Grid alarm. I checked the logs, and there are no other alarms showing

 

[Solar Guppy]

The unit is showing an alarm ( blinking yellow light ) which would indicate fault condition which the text on the top indicates no grid. One can have comms OK shown, just means data is being sent / received not that there is voltage at the battery connections to the inverter. Yes when the green light comes on, it would enabling the relay for selling to the grid if your selected grid profile connects in 10 seconds.

In re-reading and some google to understand your terminology, I want to make sure you understand 2 important items.

First is the backup port will need a seperate power distribution panel, you can't backfeed into the main "CU" if I get the terminology you are using. This second panel and breakers is called a critical loads panel in the USA

Second is the unit MUST HAVE circuit breaker with the correct current rating ( look in the manual for the value ) for the grid port connection, never connect anything to the "Henley" block as that is a direct, unprotected connect to the external to the home power source ( Grid )

Below is an image I found in Google and modified it to highlight in yellow the breaker you have not described in your installation and added the critical load panel so you understand you can't backfeed to the "Fuse board" from the backup port but are required to have a second one if you want to power in the event of a grid failure.

You can back feed energy when the grid is present ( selling energy from the battery or solar ), but this requires the grid is present as uses the grid ports NOT backup ports for this feature.

 

[SeaGal]

Just to clarify, the unit powers up fine with DC and stays on

That doesn't fit with your video though can you clarify, thanks.

- but doesn't push any battery power into the CU

via the AC-grid connection you mean? Assuming so, then check what the screen shows for house usage and grid import. If importing rather than using battery could be that your CT clamp is on the wrong way round.

. I know it can (i.e. isn't defective), as I got it to do so quite contentedly.

How / when?

I can't work out though why it detects grid in startup, but then once "operational", decides it can't detect the grid and spits out a NO-Grid alarm. I checked the logs, and there are no other alarms showing

That doesn't make sense. Are you sure you have power at the AC-Grid connection? Check it with a multi-meter.

 

[Ranging6880]

@Solar Guppy Thanks.

I'm not using the Backup port now so as to simplify this troubleshooting

I have no interest or need to export energy to grid; Zero Export ability was one component of selecting this inverter

Inverter does have a Type B RCD between it an the mains, apologies for the omission

Re "backfeed" in my original post; the transfer switch (100A DPDT On-Off-On) prevented this situation - it meant either the inverter was in the circuit, supplying CU from Backup port, OR Inverter + Battery were completely out of the circuit (with rotary isolator closed), and CU supplied directly from mains.

 

[SeaGal]

The unit is showing an alarm ( blinking yellow light ) which would indicate fault condition which the text on the top indicates no grid. One can have comms OK shown, just means data is being sent / received not that there is voltage at the battery connections to the inverter.

In re-reading and some google to understand your terminology, I want to make sure you understand 2 important items.

First is the backup port will need a seperate power distribution panel, you can't backfeed into the main "CU" if I get the terminology you are using.

yes, CU or "Consumer Unit" is UK terminal for the main house fuse / distribution box.

 

[Solar Guppy]

[Re "backfeed" in my original post; the transfer switch (100A DPDT On-Off-On) prevented this situation - it meant either the inverter was in the circuit, supplying CU from Backup port, OR Inverter + Battery were completely out of the circuit (with rotary isolator closed), and CU supplied directly from mains.

That would connect the backup port to the grid input port as the CU also has the gridport connected?

I would remove / bypass the isolator, and just follow the image I posted.

If I am still misunderstanding, please draw what you have.

I have no interest or need to export energy to grid; Zero Export ability was one component of selecting this inverter

Yes, it can be configure using the external meter to have a close to zero export with the correct settings, but will only do so if there is grid present ( connected using grid port on inverter, to the CU panel through a breaker. Connecting the Backup port to the distribution panel is not recommended as it would likely overload the unit and you have to open the gridport breaker first or you are shorting the backup port to the gridport on the inverter. this is why you should have a critical loads panel

 

[SeaGal]

Second is the unit MUST HAVE circuit breaker with the correct current rating ( look in the manual for the value ) for the grid port connection, never connect anything to the "Henley" block as that is a direct, unprotected connect to the external to the home power source ( Grid )

Inverter does have a Type B RCD between it an the mains, apologies for the omission

An RCD is not a circuit breaker as such, it only disconnects when there is an imbalance between live and neutral current due to something earthing where it shouldn't - hence will not protect the wiring as required by BS7671 / Building regs part P.

You will need to install an MCB (aka circuit breaker as @Solar Guppy advised) between the Solis and incoming supply. A 32A MCB will be ideal for the EH1P 6kW assuming you have at least 6mm2 connection from CU to the AC-grid port.

 

[SeaGal]

As it sounds as though the OP no longer wants to use the AC-backup facility, I'd agree he needs to simplify the wiring. The circuit diagram in the Solis installation manual is a good starting point with the addition of the MCB as discussed.

What still isn't clear to me though is answers to my points/questions in post #15.