RFI From Inverter

[Pwablo]

Hi

I am hoping this is the right place to seek some knowledgeable advice. I am an amateur radio operator and have recently had a new build property developed next door to mine in a very rural setting. Unfortunately the developers have installed a very noisy Sunsynk ECCO Hybrid 3.6Kw inverter and the amount of interference it is generating has rendered my radio equipment inoperable for some 2 months now. Ofcom identified the source of the noise initially, but seem unable to act, but fortunately the installer seems willing to help install some mitigation if I determine the solution and bare the costs. So far we have identified that the RFI drops significantly but not completely when the DC side to the panels are isolated, and also I noticed a drop in noise levels when cheap clip on ferrites were installed on the cables to the strings, however some RFI is still escaping when the inverter is in production mode, so we believe that the AC cable is also being used as an antenna. We dont believe that ferrites are sufficient to address any differential mode currents, so it is clear that a more robust and professional solution will be called for.

I am after some advice if anyone can help? I have limited experience with solar systems, but have found that there a few manufacturers who produce EMC filters for both AC and DC applications specifically for solar inverters, to help systems meet the mandatory EMC requirements as per the Essential Requirements directive. To name a few, TE Connectivity, Shaffner and TDK Lambda. Have any of the installers here fitted such filters before? What type could be recommended in this instance? The panels are 335W Clearline Fusions PV 16's 14 off in 2 arrays of 7 panels each. The string voltage is 252V and the current 10.3 Amps. The max AC current for the Inverter is 17W @ 250VAC.

I have data sheets for the Inverter and the Panel, which I can provide if anyone is up to the challenge?

My initial thoughts are 2 off Shaffner FN2200B-25-33 DC EMC filters for the Solar panels and 1 off Shaffner FN2090LL-30-08 AC EMC Filter on the AC cable to the consumer unit. Am i on the right track here?

Any help would be greatly appreciated with this issue, as I have not asked for any of this hassle, it has pretty much been dumped on me and I really dont want to have to give up my hobby and enjoyment of my home as a result.

Thanks in advance.

Paul

 

[binky]

Not an issue I've ever come across. However, some initial.thoughts :-
1/Check DC cable runs, the +ve and -ve cabling should be run together as much as possible. That's actually a recommendation to prevent damage from lightning emf waves, and recognises the simple fact the dc cables form an aerial.
2/ If the AC cables are an issue, perhaps change them for armoured or fire alarm cable to provide shielding that can be earthed.

 

[Geoff1946]

Have you tried contacting the engineering support department of companies such as Shaffner ? You just might find someone both knowledgeable and helpful. Perhaps worth a few e-mails.
Thinking about the DC side, it strikes me that whatever you do with the feeder cables, screening, keeping together, etc the whole solar array is going to be a large loop antenna, so stopping the RF getting up there would be my priority.

 

[Pwablo]

Hi Many thanks for your comments. It is something I had not thought about, however I dont know how practical making these modifications would be now as the house has just been completed and signed over to the new owners. I am not surprised that there is little awareness of this issue, as very few solar installs are sited next to people with the equipment to detect the interference. The manufacturers know this and once accredited with the necessary standards they have been accused of removing the critical EMC components to reduce their production costs. I recently read an article from Sweden where 3 well known manufacturers had been banned for selling products that failed to meet the EMC standards...Growatt, Solar edge and one other.

Thanks again for your comments.

 

[Pwablo]

Have you tried contacting the engineering support department of companies such as Shaffner ? You just might find someone both knowledgeable and helpful. Perhaps worth a few e-mails.
Thinking about the DC side, it strikes me that whatever you do with the feeder cables, screening, keeping together, etc the whole solar array is going to be a large loop antenna, so stopping the RF getting up there would be my priority.

Hi

Thanks for the reply. You make a good point. I tried to call Shaffner yesterday but got hung up on twice. I will try again though. Its increasing difficult to find any help for this issue, as it seems to be outwith most peoples experience and/or scope of knowledge unless within radio circles, where EMC issues in general are widly appreciated and discussed.

 

[binky]

Hi

Thanks for the reply. You make a good point. I tried to call Shaffner yesterday but got hung up on twice. I will try again though. Its increasing difficult to find any help for this issue, as it seems to be outwith most peoples experience and/or scope of knowledge unless within radio circles, where EMC issues in general are widly appreciated and discussed.

not many radio hams around these days. But I'm not surprised by Chinese products not really meeting regulations - who would have thought it!

 

[newfutile]

I would check the emc compliance from the manufacturer ,it's also part of BS7671 to check compliance of all installed devices

 

[ProDave]

I have 2 inverters and a ham radio licence.

The big Sunny boy inverter is fine. It's the little 600W cheap Chinese one that is noisy. I tried an RFI filter on the mains, that just tripped the RCD, obviously not right for the job, so if I want to use my radios I switch off the little Chinese inverter. Obviously you can't do that if it is not in your house.

Nobody but a radio ham would notice, it does not interfere with anything else. not even normal broadcast radio.

 

[Geoff1946]

I would check the emc compliance from the manufacturer ,it's also part of BS7671 to check compliance of all installed devices

Unfortunately I think that's easier said than done. The equipment will undoubtably have a CE mark, and in principle there should be supporting technical reports from laboratory tests, demonstrating compliance with standards.
If however the design has been subsequently modified, such as omitting components, that would be extremely difficult to detect, and practically impossible to prove.
After all, the manufacturer/supplier is hardly going to be co-operative.
Actually taking measurements in the field would also present serious difficulties, requiring sophisticated test equipment and the knowledge to use it. Then, who would accept evidence gathered in non-laboratory conditions?

It is my personal opinion that where EMC is concerned the CE legislation is probably widely abused.

 

[Pwablo]

I would check the emc compliance from the manufacturer ,it's also part of BS7671 to check compliance of all installed devices

Hi

Thanks for the reply. I emailed Sunsynk in early December and got a reply from their Technical Support last week stating to "Enable Low Noise Mode" in the battery settings page.....Needless to say this made no difference at all to the RFI. I wish I could actually speak to someone who had some technical knowledge at Sunsynk, but this thus far has proved to be very difficult to manage. AFAIK they are under no obligation to issue the product CoC which would be the legal document stating the compliance, to the public, but they do have to give it to the likes of Ofcom if requested. I have emailed Ofcom asking if this was done, but go no reply (No surprise's there then). The Sunsynk support is based in Hong Kong, and the installer has said that seeking help is challenging due to the language barrier etc.). I'm also not sure how willing they would be to help a non customer, and more so one who is tactically encouraging them to admit their product is **** and potentially non compliant (which IMO it probably is, cause if it was'nt it would'nt be spewing out such high levels of spurious RF all over the HF spectrum). I will however keep trying, I have emailed them again today but, im already 2 months in with no radio use, and i dont want to have to wait another month for another red herring dead end response from their 1st line Tech Support.
I will have a look at BS7671 thanks for that. If however it binds the installer in any way, Id rather not go down the route of quoting standards and obligations....I have them on side at the moment, and if I annoy them in any way I could be out of options very quickly to get this sorted.

 

[Pwablo]

Unfortunately I think that's easier said than done. The equipment will undoubtably have a CE mark, and in principle there should be supporting technical reports from laboratory tests, demonstrating compliance with standards.
If however the design has been subsequently modified, such as omitting components, that would be extremely difficult to detect, and practically impossible to prove.
After all, the manufacturer/supplier is hardly going to be co-operative.
Actually taking measurements in the field would also present serious difficulties, requiring sophisticated test equipment and the knowledge to use it. Then, who would accept evidence gathered in non-laboratory conditions?

It is my personal opinion that where EMC is concerned the CE legislation is probably widely abused.

Nail on head....this is my conclusion also. I have however heard of a radio guy who got an inverter installed and found it to be noisy as hell. He sent the device to a testing lab, found it failed and went back to the manufacturer who changed the design. It cost him loads to do but now the product is much better. I dont know if he was reimbursed in any way financially or not.
The CE marking is widely abused, there was a case not so long ago of Chinese products going to the EU market with CE marking with a slightly different font. with tiny writing below saying Chinese Export....ofc at fist glance this looks like an authentic CE mark. This coupled with some fraudulent CoCs and Importers needs are met. The bigger issue is that EU wide trading standards are incapable of policing products effectively....what resources they do have to enforce compliance is more orientated towards safety, like glass eyes on Teddy Bears and dangerous electronic construction. EMC is far down their list.

 

[Pwablo]

I have 2 inverters and a ham radio licence.

The big Sunny boy inverter is fine. It's the little 600W cheap Chinese one that is noisy. I tried an RFI filter on the mains, that just tripped the RCD, obviously not right for the job, so if I want to use my radios I switch off the little Chinese inverter. Obviously you can't do that if it is not in your house.

Nobody but a radio ham would notice, it does not interfere with anything else. not even normal broadcast radio.

Hi Dave thanks for commenting. I think it is being generally noted that the majority of EU manufactured Inverters comply with the EU legislation and produce very little RFI as all products should to meet the requirements of the Essential Requirements. The problems seems to be the cheap stuff coming in from else where. Its not just Inverters either, there are some very eye opening videos on YT showing switched mode power supplies with blocks of concrete inside in place of torroid cores, to give them the weight to pass off as quality devices. EMC suppression circuits is the first thing to get ripped out when cost cutting is required. Its the Health and Safety of the electronic world

Have sunny boy 3600TL directly below my yagi in the garage, and have zero RFI from it also.

 

[runningpiglet]

Hi

I am hoping this is the right place to seek some knowledgeable advice. I am an amateur radio operator and have recently had a new build property developed next door to mine in a very rural setting. Unfortunately the developers have installed a very noisy Sunsynk ECCO Hybrid 3.6Kw inverter and the amount of interference it is generating has rendered my radio equipment inoperable for some 2 months now. Ofcom identified the source of the noise initially, but seem unable to act, but fortunately the installer seems willing to help install some mitigation if I determine the solution and bare the costs. So far we have identified that the RFI drops significantly but not completely when the DC side to the panels are isolated, and also I noticed a drop in noise levels when cheap clip on ferrites were installed on the cables to the strings, however some RFI is still escaping when the inverter is in production mode, so we believe that the AC cable is also being used as an antenna. We dont believe that ferrites are sufficient to address any differential mode currents, so it is clear that a more robust and professional solution will be called for.

I am after some advice if anyone can help? I have limited experience with solar systems, but have found that there a few manufacturers who produce EMC filters for both AC and DC applications specifically for solar inverters, to help systems meet the mandatory EMC requirements as per the Essential Requirements directive. To name a few, TE Connectivity, Shaffner and TDK Lambda. Have any of the installers here fitted such filters before? What type could be recommended in this instance? The panels are 335W Clearline Fusions PV 16's 14 off in 2 arrays of 7 panels each. The string voltage is 252V and the current 10.3 Amps. The max AC current for the Inverter is 17W @ 250VAC.

I have data sheets for the Inverter and the Panel, which I can provide if anyone is up to the challenge?

My initial thoughts are 2 off Shaffner FN2200B-25-33 DC EMC filters for the Solar panels and 1 off Shaffner FN2090LL-30-08 AC EMC Filter on the AC cable to the consumer unit. Am i on the right track here?

Any help would be greatly appreciated with this issue, as I have not asked for any of this hassle, it has pretty much been dumped on me and I really dont want to have to give up my hobby and enjoyment of my home as a result.

Thanks in advance.

Paul

Are you a member of the RSGB ? They have an experienced team on the QRM helpdesk and solar inverters are a big issue - they have sometimes helped. If you aren’t in the UK perhaps your national amateur radio society has a similar resource?

 

[Pwablo]

Are you a member of the RSGB ? They have an experienced team on the QRM helpdesk and solar inverters are a big issue - they have sometimes helped. If you aren’t in the UK perhaps your national amateur radio society has a similar resource?

Hi thanks for commenting. Yes I have been in regular contact with RSGB EMC Helpdesk and also Dr D Lauder the Author of Radcom EMC Matters (RSGB magazine). As helpful as they have been there is little they can do, as the society does not have any enforcement powers unfortunately.

Cheers

 

[apprentice87]

Years ago teh GPO would have forced the neighbours to stop emiting the interference. Who is in charge of such stuff now??

john

 

[Pwablo]

Years ago teh GPO would have forced the neighbours to stop emiting the interference. Who is in charge of such stuff now??

john

Hello John. Should be Ofcom, but they dont seem to be very efficient in doing their job. I really dont think they have the resources to pursue costly investigations, and continuously seem to be draggged in front of the Ombudsman.

 

[fourtytwo]

In my last house I had severe interference knocking out my internet (ADSL), I searched for and found the culprit (a nearby commercial garage using Chinese electronic ballasts on workshop lighting). However the owner refused to do anything, BT/Openreach would do nothing, the ISP would do nothing and even though I was able to show blotting out of various AM radio stations neither Ofcom or the BBC wanted to know. So in answer to another comment nobody now enforces the legislation.
I have also encountered various other Chinese products over the years that caused problems, one a laptop power supply I opened up and found all the filtering components had been removed!

The problem with clip-on ferrites is they don't produce enough inductance to effect the relatively low fundamentals and the powerful harmonics of typical switching frequencies of only 10's of Khz, you need pretty big wound common mode chokes. You could try chatting to Wurth UK, they might be interested in providing some samples if they can use your case.

 

[Radiotowers]

Hi

I am hoping this is the right place to seek some knowledgeable advice. I am an amateur radio operator and have recently had a new build property developed next door to mine in a very rural setting. Unfortunately the developers have installed a very noisy Sunsynk ECCO Hybrid 3.6Kw inverter and the amount of interference it is generating has rendered my radio equipment inoperable for some 2 months now. Ofcom identified the source of the noise initially, but seem unable to act, but fortunately the installer seems willing to help install some mitigation if I determine the solution and bare the costs. So far we have identified that the RFI drops significantly but not completely when the DC side to the panels are isolated, and also I noticed a drop in noise levels when cheap clip on ferrites were installed on the cables to the strings, however some RFI is still escaping when the inverter is in production mode, so we believe that the AC cable is also being used as an antenna. We dont believe that ferrites are sufficient to address any differential mode currents, so it is clear that a more robust and professional solution will be called for.

I am after some advice if anyone can help? I have limited experience with solar systems, but have found that there a few manufacturers who produce EMC filters for both AC and DC applications specifically for solar inverters, to help systems meet the mandatory EMC requirements as per the Essential Requirements directive. To name a few, TE Connectivity, Shaffner and TDK Lambda. Have any of the installers here fitted such filters before? What type could be recommended in this instance? The panels are 335W Clearline Fusions PV 16's 14 off in 2 arrays of 7 panels each. The string voltage is 252V and the current 10.3 Amps. The max AC current for the Inverter is 17W @ 250VAC.

I have data sheets for the Inverter and the Panel, which I can provide if anyone is up to the challenge?

My initial thoughts are 2 off Shaffner FN2200B-25-33 DC EMC filters for the Solar panels and 1 off Shaffner FN2090LL-30-08 AC EMC Filter on the AC cable to the consumer unit. Am i on the right track here?

Any help would be greatly appreciated with this issue, as I have not asked for any of this hassle, it has pretty much been dumped on me and I really dont want to have to give up my hobby and enjoyment of my home as a result.

Thanks in advance.

Paul

Hi Paul,
Have you access to the April 2016 Arrl QST magazine ?
There is an article in there from Tony Brock Fisher K1KP using a solar edge system an how he reduced RFI .
I installed a growatt system last june, I get RFI but I can easily work around any the sprogs , my local noise is generally louder.

 

[Pwablo]

Hi Paul,
Have you access to the April 2016 Arrl QST magazine ?
There is an article in there from Tony Brock Fisher K1KP using a solar edge system an how he reduced RFI .
I installed a growatt system last june, I get RFI but I can easily work around any the sprogs , my local noise is generally louder.

Hi there...Thanks for making a post. I dont have access to that article in ARRL unfortunately, but I will have a look for it and see if I can find it outwith ARRL. I was looking for David Lauders article in Oct 2023 Radcom also, but RSGB have website issues and Im having difficulty getting that also. I generally dont have any local RFI issues to worry about as Im very rural....I have had zero noise floor and very little unmanageable RFI for 13 years. Thats what makes this situation so gutting.... from zero to 80% of HF wiped out over night. My spectrum scope on the IC7600 now has 4khz wide blank carrier spikes that are S9+15dB, every 30khz from 8Mhz to somewhere over 30 Mhz (although I suspect it goes a bit higher, I just dont have resonant antennas between 30Mhz and 2m band to see how far up it goes)

Growatt where pulled up in Sweden for non compliance regarding EMC. I dont know what model it was but it was published online....PV Magazine
The Dutch seem to be a bit more proactive in addressing Solar PV EMC Issues also, stating that MOST Inverters do not meet the EMC standards... HERE

If you are getting RFI on your own system then tracking down the leak path and sticking in a few dedicated EMC filters shouldnt be too difficult. You dont have to live with your solar RFI.

EDIT - Found a pdf online. Interesting read, however his sytem was using optimizers. In my case the system has none, and is simply a very dirty inverter.

 

[Stevie G]

Hi ,i know this may not have any bearing on the above ,but we fitted loads inverters forAHU fan motors, pumps etc .Replacing star/delta starters . Mostly in hospitals ,so didn't want spurious RF in a hospital environment.
Where possible we kept the inverter as close to the motors as possible, as 3 phase mains supply was alway unscreened, but from the inverter to motor, was wired in screen cable ,and the screen cable was specifically required to be SY cable and glands to prevent radio interference .
These were Danfoss Vlt FC 301Inverters, ABB ACS550 and LS 100 series . Google the installation instructions and they explain in detail how cable screen is to be terminated .
Cheers Steven

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