Kitz Forum

Broadband Related => Broadband Technology => Topic started by: simoncraddock on June 13, 2015, 02:42:32 PM

Title: Solar Panels & FTTC
Post by: simoncraddock on June 13, 2015, 02:42:32 PM
Wasn't sure which section to put this in...

Has anyone had issues with Solar Panel systems possibly causing interference to VDSL?

I had some installed on Wednesday morning but noticed Friday morning I had notched up over 400 ES/35 SES on my Fritzbox over the past 24hrs . Around 10am that morning I lost synch twice in quick succession and Interleaving depth of 1325/220 was applied with Delay 8/8 INP 3/2.5.

Today errors are minimal with 5 ES since popping the HG612 on-line 4hrs ago to try see what's happening, it's a dull wet day so fairly low output from the PV array compared to Wed/Thu/Fri.

I've looked on Google and there's very little evidence to support my theory but I've contacted the Solar Panel company who will probably respond Monday.


Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 13, 2015, 02:53:58 PM
So how does the technology work?  :-\  The PV array generates a DC voltage. At some point it is transformed into an AC voltage. That process of DC to AC conversion probably results in harmonics right up into the RF spectrum.

xDSL works by using very low power RF transceivers attached to either end of a metallic pathway. That metallic pathway does act as an aerial.

I'm not suggesting that one technology actually precludes the other technology operating correctly  :o  but it is certainly something to consider.  ???
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 13, 2015, 02:57:36 PM
My other issue is I still have scaffolding up outside which is resting directly against the incoming BT Line. I guess this could also be acting like a huge antenna  :'(

In the meantime I've ordered some copper RF shielding mesh to construct a Faraday Cage around my xDSL router to see what happens.
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 13, 2015, 03:10:33 PM
I don't want you to rush off and commit to spending more money.  :no:  I just posted what came to mind as a possible scenario which might account for your observations and as a starting point for a discussion amongst technically minded kitizens.
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 13, 2015, 03:14:48 PM
I ordered that last night off a well known auction site, A3 sheet for under 10.
Title: Re: Solar Panels & FTTC
Post by: Dray on June 13, 2015, 03:29:47 PM
I think if there is any RF interference, you should be able to hear it on a cheap radio.
Title: Re: Solar Panels & FTTC
Post by: 4candles on June 14, 2015, 08:41:29 AM
...but you get a better class of interference on a Roberts.   ;)
Title: Re: Solar Panels & FTTC
Post by: lloyd on June 14, 2015, 10:35:50 AM
I experience no correlation between solar panel generation and any errors or change in snrm. Don't know what your setup is, but I have a reasonable physical separation between the modem and inverter (one in loft, one on the ground floor). 

What I do see though is a good correlation between rain/high humidity and decrease in snrm.
Title: Re: Solar Panels & FTTC
Post by: JGO on June 14, 2015, 10:38:21 AM
FWIW my next door but one neighbor had had solar panels since before I went to ADSL. I've never seen the sort of interference I'd expect from that (a repetitive spectrum with an average  6dB/octave averagel falloff with frequency.) which suggests it is below the modem noise.  I do get a bit from BC stations. but not significant. This is with underground phone cables.

Of course if some cheap jack firm omits the filtering it could happen !
 


Title: Re: Solar Panels & FTTC
Post by: Black Sheep on June 15, 2015, 08:33:10 PM
Once had a REIN job, that the engineer who raised the case commented he could hear extreme 'Noise' coming from a house approximately 10 houses up from the complaining EU. The only one with solar panels on the roof.

Myself and another engineer visited a few days later, and at first thing in the morning (0800). It was perfectly quiet wherever we drove around the estate. Then about 1030, boom !!! The 'Noise' on the van radio was deafening, and right outside the house the previous engineer had mentioned in his notes.

By now the lady of the house was home and she put us in touch with her husband. turned out he was some electrical genius who fully understood what I was trying to convey. But, he was adamant it would not be broadband service affecting 'Noise'. He told us that the cells (Solar Panels) have to gather up x amount of energy, before the inverter kicks in (The boom we heard at about 1030) and starts to supply the National Grid.

How much of that is true about the cells/inverter/supply ..... I don't know ..... but the Spectrum Analyser showed us that it was indeed non-service affecting 'Noise' with regard to ADSL. Turned out the complaining EU needed a new D-side ....  ::).

JGO is the man, the myth, the legend on this subject ...... and his comments above would concur with what we found. I've only ever had that one occasion to suspect solar panels as a source of REIN, based on another engineers viewpoint.   
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 15, 2015, 08:42:15 PM
Thank's guys for the input.

I'm waiting to see if the Interleaving is removed in the next few days, so far errors are minimal. If interleaving is removed and the errors go through the roof again then I'm not sure how to proceed other than turning off the inverter temporarily to see if they cease.

Could scaffolding which is resting directly against the line be a possible cause by acting like a huge antenna?
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 15, 2015, 09:59:07 PM
Could scaffolding which is resting directly against the line be a possible cause by acting like a huge antenna?

Unless the scaffolding is making intimate contact with the metallic core of one of the wires within the drop-cable then I would not expect it to be causing any problem. Assuming the scaffolding is not going to remain there for ever then just check again once it has been removed.
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 15, 2015, 10:44:55 PM
Similar story...

http://forums.overclockers.co.uk/showpost.php?p=28177598&postcount=2376

[edit] user just stated he had multiple power outages due to on-going work
Title: Re: Solar Panels & FTTC
Post by: JGO on June 16, 2015, 03:21:23 PM
This new link give some information on the regulation of solar panel emissions := 

http://www.southgatearc.org/news/2015/june/standard_for_photovoltaic_inverters_provides_relief.htm
Title: Re: Solar Panels & FTTC
Post by: npr on June 16, 2015, 04:25:52 PM
Could scaffolding which is resting directly against the line be a possible cause by acting like a huge antenna?

Unless the scaffolding is making intimate contact with the metallic core of one of the wires within the drop-cable then I would not expect it to be causing any problem. Assuming the scaffolding is not going to remain there for ever then just check again once it has been removed.

Would it not be possible that's it's making a capacitive coupling to ground or antenna?
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 16, 2015, 04:50:29 PM
Would it not be possible that's it's making a capacitive coupling to ground or antenna?

There would be a very, very, minute degree of capacitive coupling, yes. To both legs of the differential pair, equally. But I think it would be very difficult (tending towards impossible) to measure or quantify. Certainly nothing to worry about.  :)
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 16, 2015, 04:55:37 PM
This new link give some information on the regulation of solar panel emissions := 

http://www.southgatearc.org/news/2015/june/standard_for_photovoltaic_inverters_provides_relief.htm

Thank you for that link. I see it is relatively up-to-date and essentially provides some metrics to my caterwauling, above.  :angel:
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 17, 2015, 12:54:04 PM
I'm now running a HG612 inside a small home made Faraday Cage and in the past 15 hours no CRC/ES/SES errors have been recorded (yay) other than a handful that I've found were caused turning on/off my electric shower this morning. I'm tempted to try copper paint on the inside of the modem, the cage is rather a ugly thing.

Does anyone know if fitting a 'Delta Suppression Filter' to my shower will help matters?
Maplins list one but I'm not sure if this is ok with a 9kw shower, anyone?

http://www.maplin.co.uk/p/delta-suppression-filter-rg21x
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 17, 2015, 03:59:52 PM
Does anyone know if fitting a 'Delta Suppression Filter' to my shower will help matters?
Maplins list one but I'm not sure if this is ok with a 9kw shower, anyone?

http://www.maplin.co.uk/p/delta-suppression-filter-rg21x

I'm not sure. I wouldn't think the shower's power loading is relevant.  :-\

Perhaps ask the question via the page on the Maplin website (http://www.maplin.co.uk/p/delta-suppression-filter-rg21x)?

Perhaps NewtronStar will have an opinion? I know that he spent some time fitting surge suppression filters to various electrical devices in his home . . .
Title: Re: Solar Panels & FTTC
Post by: lloyd on June 18, 2015, 01:11:57 PM
Out of interest, what make and model of inverter are you using?
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 18, 2015, 03:56:51 PM
Out of interest, what make and model of inverter are you using?

It's a Trannergy PVI4000TL

http://www.trannergy.com/product/detail.aspx?id=35&classId=144397762564194304
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 26, 2015, 12:21:36 PM
Just a quick update...

The scaffolding in front of my home was removed a couple of days ago which was really tight up against my incoming line. Overnight DLM put the US back on fastpath, so just the DS to catch-up now.

Seems more than a coincidence that my line has improved since it was removed. Errors after 8 hrs are still at zero so hopefully it will act on the DS soon.
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 26, 2015, 04:32:57 PM
It is interesting you now have evidence that the scaffolding was having a detrimental effect on your circuit.

Knowing the effect and now knowing the cause, I wonder if anyone would like to propose a potential theory as to what was occurring?  :-\
Title: Re: Solar Panels & FTTC
Post by: simoncraddock on June 26, 2015, 05:36:12 PM
It is interesting you now have evidence that the scaffolding was having a detrimental effect on your circuit.

Knowing the effect and now knowing the cause, I wonder if anyone would like to propose a potential theory as to what was occurring?  :-\

More coincidence than hard evidence, but I've reached 13 hrs up time with zero CRC/ES errors on both US/DS which is better than when it was in place.
Title: Re: Solar Panels & FTTC
Post by: burakkucat on June 26, 2015, 06:28:46 PM
More coincidence than hard evidence, but I've reached 13 hrs up time with zero CRC/ES errors on both US/DS which is better than when it was in place.

 :thumbs:   :fingers:
Title: Re: Solar Panels & FTTC
Post by: WWWombat on July 02, 2015, 10:17:45 AM
I'd say it was managing to create some level of inductance or capacitance in the pair.

Perhaps the scaffolding was acting somewhat like the directors or reflectors in a Yagi aerial, with the pair as a dipole.
http://www.radio-electronics.com/info/antennas/yagi/yagi-antenna-theory.php