Need advice please

[SolarCity]

Tell her to come on the forum and face the trade. I think they're an utter waste of money.

REAL is there to protect the customer, but the PV trade is like the Wild West. I've never known an industry like it.

 

[dansk]

You know what i will!!

 

[Gavin A]

G83/1 limit is 264V. Various European jurisdictions use 253V. That inverter model does have G83/1 certification (from cert on Omnik site). Whether it is in reality on G83 settings is another matter. Often during boot up the inverter will say what it is on, but I do not know the Omnik range. Limits are below:
G83/1
View attachment 17295
G83/2
View attachment 17296

it is, but then the main supply regs require the DNO to supply at below 253V 10 minute average, and part of G83 is that we must ensure the supply remains within these requirements as well... so even though it's not mentioned in G83 specifically, there really is a 253V 10 minute average limit as well, although not that many inverters comply with this... meaning that there are many installations out there that the DNO could legally end up cutting off in future if they're only protected at the 264 level.

but that's a bit of a digression.

 

[BruceB]

I do not think I agree Gavin. The Electricity Supply Regs are defunct now. ESQC Regs apply. The 253V issue is for the DNO to sort out not us. G83 specifies certain tests for inverters. That's it, full stop. DNOs would be pressed to impose other requirements pulled out of thin air. I do appreciate DNOs might try to argue otherwise on the ground. There is under ESQC a formal procedure they have to go through if they want to cut you off.

 

[Gavin A]

G83/1 engineering recommendations

5.4 - Quality of supply
The connectoin of the SSSEG in parallel with a DNO's network must not impair the quality of supply provided by the DNO to the user or any other customer.

Now, this sections does then go on to discuss harmonics and flicker regulations (btw this is where anyone installing Immersun devices in high impedance areas hits problems as they don't comply on a high impedance grid connection), but the quality of supply would also cover the voltage, which means the voltage not being over 253V as a 10 minute average.

This may well not be being used much at the moment, but IMO the DNO's would have the power to enforce this regardless of the specific G83 setting requirements, which can be seen as being a minimum requirement.

I know there are people who've had overvoltage issues resulting from the inverter, and after the DNO has taken the readings they've shown that it's the PV system that's regularly causing their local grid voltage to go above the 253V 10 minute average, leading to the DNO threatening to cut them off, and forcing them to pay the costs of the DNO reducing the tapping... well, I say I know, but this is second hand from DNO engineers. There was definitely a circular went round Northern Powergrid engineers to this affect a while back, saying that reducing the tappings was chargable unless the grid was already outside the limits prior to the PV being fitted.

If I remember right, SMA already have this 10 minute average 253V setting as standard on their inverters even at G83 settings, for this reason, Power-One for example doesn't, which can be good in some situations eg at the end of a longish run where you know the voltage at the inverter needs to be higher than 253V but by the time it gets to the local grid it ought to be lower, but it's playing with fire a bit in standard domestic settings with high grid voltage, particularly if there are multiple solar installs on the street.

ps does anyone know if the final G83/2 engineering recommendations have been released anywhere?

 

[BruceB]

Paragraph 5.4 is the same in G83/2, which to my reading is specific about 'quality' being to do with harmonics etc not voltage as the second sentence of the paragraph is:
"In this respect the SSEG shall comply with the requirements of the EMC Directive and in particular the product family emission standards listed in Table 2."

If the DNO has time to threaten to cut people off then it is clearly not an emergency and therefore they would have to give notice under ESQC s.26(1). If the consumer then referred the matter to the SofS under s.26(5), the DNO is not allowed to cut them off under s26(2) until the SofS has appointed a suitably qualified person to determine the dispute and it has been so determined.

Whilst I might be wrong, I would be surprised if the Goverment would let consumers using approved equipment in accordance with the regulations be stuffed by the DNO when public policy has been to encourage the connection of small scale generation. On the other hand......


My copy of G83/2 is dated August 2012.

 

[Gavin A]

the august copy is a draft then, as it was still in consultation at that point.

You may be right about the outcome if anyone actually did take it that far, but at least some of the DNOs are definitely making these sorts of noises and pointing to that section of the regulations as their justification in situations where monitoring is showing that the local grid voltage is regularly being pushed above the 253V 10 minute average limit by solar PV systems.

Northern powergrid have resolved this for the time being by applying a 6V reduction across the entire network, so it's not likely to be an issue again for a bit, but I don't think they have further leeway to repeat this across the board reduction, and this basically is the issue that they were trying to resolve via the changes around local geographic area, but as we all know, these changes won't really have any impact on the issue, so I expect this to be revisited, and probably to start becoming an issue in certain areas with high levels of G83 systems on local transformers this summer - I wouldn't be surprised if one of the DNO's decides to find a test case on it to clarify this point tbh.

IMO though the wording re 'quality of supply' would cover the 253V levels as these are clearly specified in the ESQC regulations, so forms part of the legal form of the 'quality of supply'

Regulation 27 imposes requirements to give information relating to a supply and to maintain the quality of supply within certain tolerance limits.

Regulation 27 <snip>
(2) Unless otherwise agreed in writing between the distributor, the supplier and the consumer (and if necessary between the distributor and any other distributor likely to be affected) the frequency declared pursuant to paragraph (1) shall be 50 hertz and the voltage declared in respect of a low voltage supply shall be 230 volts between the phase and neutral conductors at the supply terminals.
(3) For the purposes of this regulation, unless otherwise agreed in writing by those persons specified in paragraph (2), the permitted variations are—
(a) a variation not exceeding 1 per cent above or below the declared frequency;
(b) in the case of a low voltage supply, a variation not exceeding 10 per cent above or 6 per cent below the declared voltage at the declared frequency;

http://www.legislation.gov.uk/uksi/2002/2665/pdfs/uksi_20022665_en.pdf

put simply, IMO any DNO would be on fairly firm legal grounds to object if they could show that one or more solar systems installed under g83 were causing the local voltage to regularly exceed 253V, and for instance insist that the invert settings were updated to prevent the systems exceeding 253V in these situations.

The fact they might not have done this much yet shouldn't be taken as an indicator that they aren't planning to do so in future if the number of G83 installations starts forcing the local grid voltages above their set limits in significant numbers, particularly in areas where they don't actually have the ability to reduce the tapping further or any other simple mechanism to solve the problem... at this point I'd expect them to start knocking on doors putting the problem back into the court of the sseg owners who's systems are causing the problems.

It's actually something that's easily solvable via the inverter settings to introduce a gradual reduction in output from eg 251, 252, 253V - certainly far simpler than the DNO having to dig up and replace their cable with a lower impedance cable... something that could easily be undone with a couple more systems installed anyway.

 

[BruceB]

Regulation 27 is putting obligations on the distributor and supplier rather than the consumer, so I cannot see any legal grounds the DNO could cite under that reg to get a consumer to disconnect a properly connected G83 system.

Your point about the inverter reducing the voltage is interesting and as you say easily achievable in principle in software nowadays. But it is a level of sophistication beyond most standard inverters today. In order to reduce the voltage they would have to reduce the output current (depending on your view of the chicken and egg argument) which means the inverter would have to deliberately operate away from the mppt optimum. None of the current standard ones appear to be able to do that to control the voltage I think.

My G83-2 does not appear to be a draft, at least it does not say draft anywhere.
PDF file in ENA livery
Title is: Engineering Recommendation G83 Issue 2 (August 2012)
Filename is: ER G83-2_v5-The master 09-07-12 inc Ofgem comments - clean version.pdf
Amdt level: Issue 2 August, 2012
Did something actually change after then?

For info the ENA's view of the legal aspects from the doc is below:

 

[Gavin A]

Regulation 27 is putting obligations on the distributor and supplier rather than the consumer, so I cannot see any legal grounds the DNO could cite under that reg to get a consumer to disconnect a properly connected G83 system.

The legal grounds are section 5.4 of the G83 engineering recommendations I quoted before. If the SSEG is itself responsible for pushing the grid voltage over the 253V limit then it would be impairing the quality of supply provided by the DNO to the user and other customers.

IMO it's pretty clear cut, it's just that the DNO's haven't been pushing this too much, but if it becomes seriously problematic then there's no reason to think they won't start enforcing this - when all other options are used up, they still have an obligation to maintain the supply within that voltage range, and if that means enforcement action against SSEG owners, then that's what they'll inevitably end up doing IMO.

 

[Gavin A]

It's even written into the quote you just gave

However, under the terms of ESQCR regulation 26 the DNO may require an SSEG to be disconnected if it is a source of danger, or inteferes with the quality of supply to other customers

they clearly do have this power if they chose to apply it, and if no other options remain to keep the supply withiin the parameters allowed, then I see no reason to think that they won't use this power.

This is clearly becoming a serious issue for DNO's, as was made clear by Ofgem in discussions re the close geographic region aspect of the G83/2 regulations, and as the revisions to those regulations will have minimal if any impact on this issue, I'd expect to see DNO's starting to make use of their powers outlined above, as they actually do have a legal obligation to maintain the supply within those parameters.

 

[BruceB]

You are being too generous to them.

ESQCR 26 does not use the word quality anywhere. G83 is not the Electricity Act, nor the regulations (ESQCR) made under the act so it is becoming a bit remote to be considered direct 'legal grounds'. The reference to 'quality of supply' in G83 has a specific meaning from the second sentence of para 5.4 and it is to do with harmonics and voltage fluctuations and flicker, NOT [average] voltage. So if all you are doing is raising the voltage, that is not a quality issue within the meaning ascribed to the word in G83, so they have no grounds to disconnect unless you were taking the voltage so high it became dangerous, which a G83 installation is unlikely to do.

In my opinion, for G83 systems, the voltage problem is theirs under the legislation not yours. I suspect that the grown ups within the DNO know that and that is why they have not thrown their weight around too much to date.

 

[dansk]

Had a fast reply from Omnik - posting here for anyone in the future.

[FONT=&quot]Hello Russel[/FONT]
[FONT=&quot]May I know the total energy generated shown on the inverter display? If it is lower than 1KWh, please try this way.[/FONT]
[FONT=&quot]1. [/FONT][FONT=&quot]Disconnect AC side[/FONT]
[FONT=&quot]2. [/FONT][FONT=&quot]Press the white function button until showing “1.5K-TL”[/FONT]
[FONT=&quot]3. [/FONT][FONT=&quot]Press about 10 seconds until it occurs different countries standard [/FONT]
[FONT=&quot]4. [/FONT][FONT=&quot]Press step by step, choose “GB-83” or “Australia”( wider Vac range)[/FONT]
[FONT=&quot]5. [/FONT][FONT=&quot]Long pressing for about 10 seconds to make it effective[/FONT]
[FONT=&quot]If the total energy generated exceeded 1kwh, I think you need to choose another way, which you need is a laptop and USB-RS232 cable, you can download and refer this document below.[/FONT]
Downloads - Omnik New Energy[FONT=&quot][/FONT]
[FONT=&quot]Omnik_Safety_regulation_Model_type_Data_clearance_Reset_tool_20121217[/FONT]
[FONT=&quot]The decode password is “168168”[/FONT]
[FONT=&quot]Best Regards[/FONT] [FONT=&quot]Walter[/FONT][FONT=&quot][/FONT] [FONT=&quot]Skype ID: walter.yang_omnik[/FONT]