Neighbor's solar equipment causing slow internet speed (Sandi SDS3KW inverter) - Page 1
Forum section: electronics / general

author: BoomBrush
author_rank: Contributor
timestamp: September 13, 2018, 07:15:41 pm
content: I live in Australia. A close neighbour of ours cheaped out and got a dodgy solar system which is emitting all sorts of RF, causing our internet speed to be slowed way down. The difference in speed with neighbor's inverter switched on/off is about 16 times (not joking). We asked that neighbour to turn her solar system off, slow speed issue immediately goes away. We also notice a difference in speed during day/night, since the solar equipment doesn't work during the night it's much faster. As soon as 5am hits when the sun rises, we get heaps of dropouts in the early morning.Standing outside neighbour's house with an AM radio makes all stations unhearable and just filled with bzzzz sounds. This can be heard in this recording where I walk up to her homehttps://instaud.io/2nrf.The government body responsible for dealing with this sort of thing (the ACMA) sent a technician out who identified AM noise from the solar inverter but doesn't think its significant enough to cause AM interference or internet dropouts (despite my tests). They are also a diagnostic service only, it's up to the neighbour to fix the issue. I've contacted my ISP who sent a Telstra technician out. He's known about thisspecific solar company installing this dodgy inverter for years to heaps of other customersand he basically said he or our service provider can't do anything until NBN comes, then it's NBN's problem. This isn't an isolated situation as other people with these same model inverters from the same company are having identical issues. I have tried turning off the power at my powerbox and battery powering (DC) the modem with a laptop. With literally every single circuit breaker switched off at my circuit board, the issue remains, so I don't think it would be conducted through the mains cables if battery powering the modem gives identical symptoms.More detailed pictures of the install:https://imgur.com/a/1M5qS- The SDS3KW belongs to my neighbor, and the SDS4KW issomebody a few streets away with the identical problem.Photo I found on facebook of a failed install, posted in January 2018. Seems like DC isolator was incorrect and melted. The solar installers are identical for all of these pictures.Awesome guy sent me these pictures of his install of identical model, look slightly different. Pretty sure he was a sparkie but he said the capacitors on the inside had failed and there was oil inside the inverter. Solar company refused to warrant his product and ignored communication until he got the electrical safety officer involved.Inverter model is a Sandi SDS3KW (company also gave out SDS4KW, the chinese manufacturer is now out of business). The neighbour is a lovely older lady, which she has been extremely cooperative. Her system is still under warranty so when she got it replaced again as a result of me bugging her earlier this year, it died less than 2 weeks later and had to be replaced AGAIN (actually she's up to her 5th replacement within about 2 years). Solar company seems to have heaps of these cheap inverters lying waiting around for warranty repairs, which have6+ year old production dateson the label.The solar company responsible for installing knows about the issue and claims the inverters have nothing to do with RF and said instead that it's the mains cables being too close to the telecommunications cables, meaning a fault in the home's wiring. We had the neighbor's home checked out by the electrical safety officer for our area, he said there's nothing wrong with the mains wiring but can't say for the telecommunications (out of his area). The solar inverter was installed prior to Australian laws requiring an RCM approval mark on electrical equipment (pre-2015), meaning they are not required to comply with EMI standards, at least according to the Clean Energy Council.My guess on the problem is that the inverter, being cheap chinese junk, is missing the required DC filtering to reduce the EMI. As a result, huge currents of the solar panels at frequencies identical to those used by AM radio (500k - 1600k) and by ADSL (25k - 2MHz) are being switched on and off, which is then producing huge electromagnetic fields. These electromagnetic fields are then being induced into the neighbours telecommunication cables, down the underground piping, down about 100 metres of cable between our modem and the neighbours property. The PWM generation of the inverter is probably the part being induced onto the line, which under normal conditions should be filtered but here it's not.This graph is a plot of my ADSL connection's noise margin recorded over a period of the day. As the solar equipment starts working, you can see the connection quality (noise margin) takes a plummet. Then during sunset, it returns back to normal.In this test in the morning, the router is trying to get a connection. As a result, you can see there are hours of dropouts during 5am - 8am where the router is constantly restarting and unusable.My router will allow me to dump SNR and QLN values for each ADSL channel/bin. The colours represent different times the SNR values were recorded. When the solar equipment is on/off, the SNR of the channels/bins will significantly decrease, some will become too noisy to use (thus means less bandwidth/speed for the ADSL). In this graph I compare the SNR from 7am, 8am, 9am, 10am, 11am and 12pm as the solar equipment operates during the day.Around bin 115, the SNR goes from about 37dB at 7am down to 0db!!!!!!These were captured at night time.I tried to use my Rigol DS1102E scope to check out the telecommunications line using the math FFT, but for some reason it only shows the upload portion of the ADSL signal. No idea what that jumpy signal is towards the end, maybe part of the ADSL?This is when I disconnected the ADSL router, showing this signal correlates with ADSL (well it is between 26khz and 130khz)I've tried putting ferrite core rings wrapped on our telecommunications line with hope to get rid of some of the noise, but no luck. We currently use ADSL2+, but later this year are going to be upgraded to NBN which uses VDSL2. VDSL2 uses frequencies up to 25MHZ, I wonder if it will continue to be an issue. I also considered putting a faraday cage around the neighbours inverter, but I don't know how she'd feel about that. I've had suggestions of putting a filter on the DC side of the inverter but that would come at my expensive to hire an electrician to do that.Any ideas?Feb 2019 - Edit: My neighbour got this in the mail:We are getting NBN in likely 2 weeks. Will post update then.Please read my update

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 13, 2018, 07:28:43 pm
content: Clip-on ferrite cores on all cables coming out of the inverter may be worth a try, if only as it's easy to do and wouldn't need an electrician.

author: drussell
author_rank: Super Contributor
timestamp: September 13, 2018, 07:29:26 pm
content: There must be something wrong with your telephone wiring if you are picking up that much interference.Have you at least checked to be sure that you have proper twisted pair wiring from the telco's demarc point / NIT to your ADSL modem? With twisted pair all the way, the vast majority of induced noise should be cancelled out since it will be common to both conductors. Even very short runs with standard "handset cord" type patch cables will be able to pick up significant noise.As for trying to filter with ferrites, you don't want to try to filter your ADSL signal lines, but you might want to try filtering your power better if the noise is somehow being induced from the power line to the ADSL modem.

author: BoomBrush
author_rank: Contributor
timestamp: September 13, 2018, 07:36:11 pm
content: Quote from: drussell on September 13, 2018, 07:29:26 pmWe have Cat5e cable in the ceiling, so it shouldn't be an issue on our end. We were thinking about replacing it with Cat6 when NBN comes around however.I have tried turning off the power at my powerbox and battery powering (DC) the modem with a laptop. With literally every single circuit breaker switched off at my circuit board, the issue remains, so I don't think it would be conducted through the mains cables if battery powering the modem gives identical symptoms.

author: edpalmer42
author_rank: Super Contributor
timestamp: September 13, 2018, 08:03:26 pm
content: I agree with mikeselectricstuff that clip on ferrite cores are worth a try, but I'd put them on every single wire or cable that is connected to the inverter - input, output, and control cables. The frequencies involved are a bit low for ferrite cores, but it's so easy that you have to try it.Ed

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 13, 2018, 08:19:48 pm
content: It's a tricky situation as you don't know if it's that the inverter doesn't meet EMC standards, or it's the way it's been installed.Either wait it's probably the installer's liability but proving noncompliance is the hard part. The manufacturer being out of business also doesn't help.One approach may be to the ISP on the basis of failure to supply service, but they may not be able to do anything unless they can do fibre to your home.

author: Halcyon
author_rank: Unknown
timestamp: September 13, 2018, 10:44:52 pm
content: How close does your ADSL line run to your neighbours inverter? Does it connect to your house above or below ground?I know it's a bit of expense on your part but is it possible to re-route your incoming line to be as far from that inverter as possible? Perhaps even using shielded Ethernet cabling?I would also consider connecting your ADSL modem as close as you can to the network boundary and get rid of any excess cabling (including other sockets within the house). Run Ethernet from your modem back to where your equipment is.I do exactly this as I'm on the shitty NBN. My modem is in the garage at the point where the line comes in from the street, then using an Ethernet to Fibre converter, I run it back to my server rack.

author: VK5RC
author_rank: Unknown
timestamp: September 14, 2018, 12:53:46 am
content: As a ham, we got blamed for everything, now our training includes how to handle interference accusations, standard steps areFirst talk to your neighbourSecond try some simple measures, rf chokes, grounding issues, check cables for loose shields/bad connectionsThirdly talk to ACMA, interference with AM broadcast is an 'offence' the ACMA site is quite a good resource eghttps://www.acma.gov.au/Citizen/TV-Radio/Television/TV-reception/is-interference-causing-my-reception-problems

author: TERRA Operative
author_rank: Super Contributor
timestamp: September 14, 2018, 04:34:34 am
content: Is replacing the Cat5e with something like shielded and properly terminated Cat6A a possibility?

author: BoomBrush
author_rank: Contributor
timestamp: September 14, 2018, 09:14:11 am
content: Quote from: mikeselectricstuff on September 13, 2018, 08:19:48 pmThey suggested that since they can't supply their service as advertised, we can use a different provider as they can't fix the issue. This was from the TIO section of the company.Quote from: VK5RC on September 14, 2018, 12:53:46 amI talked to my neighbor, she knew about it because other neighbors have approached her in the past about the issue. ACMA saw AM interference but deemed it not significant enough to do anything about.Quote from: Halcyon on September 13, 2018, 10:44:52 pmUnderground, about 100 meters of wire between my property's entry point to my neighbor's entry point following the footpath and up the side of the house. I don't think the router's placement in my house would make a difference because I tried in a few locations with no change.Will definitely look into getting Cat6A cable in the ceiling but I don't think it will make much difference. Worth a shot though.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 14, 2018, 01:38:09 pm
content: If your neighbor is not using the phone lines, ask if you can disconnect the line at the service box.

author: nctnico
author_rank: Super Contributor
timestamp: September 14, 2018, 01:58:42 pm
content: Quote from: BoomBrush on September 13, 2018, 07:36:11 pmCat5e is the wrong cable. Telephone cable is 600 Ohm and Cat5e is 100 Ohm. The best thing to do is to move the DSL modem to the point where the phone company brings the cable into your home. If the problems persists then make it the phone company's problem. After all it could be their wiring as well.

author: Ziya
author_rank: Newbie
timestamp: September 15, 2018, 10:12:52 pm
content: Not an engineering solution but a social one. I dealt with a bad invisible fence company installing lines over telecom lines and causing all kinds of hell years ago.Local news people love stories like this. If you can find four our five people for them to interview send them a tip. If the stuff isn't up to the current codes they'll be all over it. Especially if you can claim you've got stuff breaking. Just make sure the guy you contact isn't owned by the telecom company that you're having trouble with. If you can point out a government official that isn't doing their job it'll be airing within the month.

author: Beamin
author_rank: Super Contributor
timestamp: September 15, 2018, 10:37:46 pm
content: How did you make those pictures both the line graph and ones under it. You said your scope can't make those?More then likely you are going to have to spend money to replace it. I know here in the US we have a small claims court for under 5000$. If a company is out of state its easier to pay the law suit then it is to send a lawyer and fight. I have even sued an ebay company in 2005 for selling a fake Bluetooth for 125$. I threatened and they just sent a check. I only paid 35$ and told them I wanted replacement cost because Motorola wanted all the companies info and for me to send the product to investigate counterfeit products. It as BS but still counterfeiting is a problem when you say new in box and genuine.

author: Circlotron
author_rank: Super Contributor
timestamp: September 16, 2018, 12:07:13 am
content: Put an earth stake right underneath the inverter and run a short direct wire from the stake to the inverter box. Short and direct is important. Earth the metal box. LC line filters both common mode and differential mode on both mains and panel side. Maybe even put the filters down at ground level so that the earth path is very short.

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 16, 2018, 11:05:20 am
content: Hmm in my Country its simple. I would call the Authorities for an unlicensed Transmission on the HF Band.

author: BoomBrush
author_rank: Contributor
timestamp: October 21, 2018, 07:45:41 pm
content: Update:It's still an issue, but we did order a second 4G antenna (in the mail still, arrives Tuesday). Hoping to get over 120mbps using carrier aggregation and MIMO. We are currently on 55mbps using a single 1800MHz 4G antenna, where the base station tower has 15MHz of bandwidth. I ordered a multiband 700MHz - 2600Mhz antenna, so I will be using the 700MHz and 1800Mhz bands in aggregation in combination with my current original antenna to get MIMO with 1800Mhz. I'm currently using 6m of RG58 which I recently discovered has huge amounts of loss, but the antenna came with some LL240 wire and a patch cable included which is good. Maybe I can post speed result?Quote from: nctnico on September 14, 2018, 01:58:42 pmThe problem really is that the phone lines are being used in 2018, it should have been abolished years ago. The plan of the NBN originally was to fix that, at least until 2013's election election happened and it became political. And yes the modem has been tested at the first plug in the home.Quote from: NiHaoMike on September 14, 2018, 01:38:09 pmShe has a home phone, but I do wonder if her disconnecting the phone line [thus her line would be open circuit] would temporarily fix the issue. Not sure.Quote from: Ziya on September 15, 2018, 10:12:52 pmAm actually considering this one, although my uni finishes in a week so maybe after that. Tracy Grimshaw is not impressed!Nah, current affair doesn't do stories unless somebody is cryingQuote from: Beamin on September 15, 2018, 10:37:46 pmI have a netgear router which has a broadcom chip inside. There is a way you can login into your router over telnet by sending it some magic packet and it unlocks a hidden command line mode. You can type commands into the linux terminal that runs on the chip and get some of the diagnostic info such as SNR for individual ADSL bins/channels. I have a raspberry pi setup so that at regular intervals, it will login and dump the channel data to a log file. I also monitor the SNR and speed using the raspberry pi over the router settings homepage, which is how I got the "noise margin" and speed graphs. It's all setup to be automatic and just save the data into a file so I can make graphs for any day and time I like.

author: fourtytwo42
author_rank: Super Contributor
timestamp: October 21, 2018, 08:43:37 pm
content: I live in a small rural village in Norfolk(UK) and get an almost identical problem except the source is industrial inverters on a farm. The problem is induction coupling from the power lines into the telephone cables, in our village both are overhead but generally on opposite sides of the street. A lot of my problem was caused by both the power and telephone wires running down the roof and along under the gutter in actual contact for a total length of some 20 meters, this combined with the use of old figure 8 telephone drop cable instead of the modern twisted stuff. This was the last problem AFTER I had eliminated many problems in the house including unused extensions still connected and connections made using 1 wire each from different pairs! Anyway it took me a very long time to persuade the ISP to persuade the TELCO to change the drop wire and re-route it, I think the evidence from DSLSTATS (again using a TP-LINK (the later ones don't work) with a Broadcom chipset ) helped twist there arms. So to recap your most likely problem is induction caused by telephone and power cables being in immediate proximity over some distance (of course you also need to debug any internal wiring faults as well).BTW I have had no success against the source despite it knocking out a national radio station from the so called regulatory authorities!

author: TomS_
author_rank: Frequent Contributor
timestamp: October 22, 2018, 09:37:41 am
content: Quote from: mikeselectricstuff on September 13, 2018, 08:19:48 pmIt would be very rare to purchase a residential broadband service in Australia and have it come with any kind of SLA or guarantee, so this probably would not work.Your best bet is to try and find an issue with the telephone service, like hissing or crackling noises. Ideally if these are present then your telephone provider should be able to detect this and send a tech out to resolvethatissue, which also likely fixes what ever ails the broadband service.I used this very "technique" to get a problem that affected the sync speed of my parents ADSL service fixed up. You could hear crackling when you picked up the phone, so I reported the issue to Telstra (their telephone provider). They did indeed detect an issue, and sent a tech out (who came the next day, despite them saying it would be a couple of weeks), replaced some gel caps/splices in a box on the side of the house, and hey presto, fixed up the crackling noises and also restored several mbit of sync speed.I used to work on a level 2 ISP helpdesk and had to deal with this kind of stuff all the time. Its a pain in the arse and you have to deal with some right pillocks who want 20mbit on a 5km line. Probably why I dont do it any more.

author: BoomBrush
author_rank: Contributor
timestamp: October 22, 2018, 09:51:49 am
content: Quote from: TomS_ on October 22, 2018, 09:37:41 amWe did. The technician happen to be a guy who lived on the same street as us, and so he was super familiar with the issue because he was also affected and tried fixing it himself. He actually once helped me push my car home once when it stalled in front of his house. Apparently based on his callouts, anybody with this model solar equipment has the identical issue and it was extremely common (apparently 7 people in my neighborhood alone have the identical problem). He said Telstra had spent so much time with level 2 techs doing tests between the properties and the exchange for each house who reported this problem with this model solar equipment that they decided to just ignore any problems related to it. Something about costing too much and NBN coming soon.Apparently he got so up the solar company trying to fix the issue, they allegedly threatened to sue him for deformation because he was "misinforming" people, even though he works at Telstra, had evidence and had done tests to prove the claims. Seems more like the solar company didn't want people to know about its dodgy business practices.Edit: I should point out in 2016, another neighbor on my street reported slow internet, that is when the issue was discovered. The solar company was initially cooperative with replacing the solar equipment after the Telstra tech informed them of the situation (so they actually fixed it for that guy), but I suspect they didn't realizedit was not a once off, instead the problem existed for every single model of that equipment. So I think the Telstra tech kept expecting the solar company to replace the inverters and so when it started costing solar company more than just a once off he realized he is going to lose heaps of money so told the Telstra tech to bugger off and is now refusing to acknowledge the problem.Solar company told us the Telstra tech didn't know what he was talking about, and that the issue is from the wiring of the house with the mains cabled being too close to the telecommunication cables (um, what?). We had electrical safety officer check it out and he didn't see any issue. It's even worse that with this whole thing, her system is still under 10 year warranty.

author: Zucca
author_rank: Unknown
timestamp: October 22, 2018, 10:08:42 am
content: Now I will hook up my cheap ass rigol SA to the phone lines and check what I get....Doing the test late at night... Hoping that nobody calls me during the test otherwise boom..Thanks for posting this.

author: fourtytwo42
author_rank: Super Contributor
timestamp: October 22, 2018, 07:12:05 pm
content: Quote from: BoomBrush on October 22, 2018, 09:51:49 amUnfortunately you don't seem to have read my post, that's exactly what I told you too!! And induction has nothing to do with electrical safety so no surprises there. It is very unlikely the inverter will have been approved for use if it had a serious and non-compliant noise issue so the more likely problem is with your particular broadband connections that may well have not had a problem prior to the inverter installation but that does not mean they are fault free. Most Telco Techs don't understand induction beyond it being so bad they can hear supply frequency hum on the phone so you have to check it yourself. As I said every piece of wire in the building and the route and style of it outside. Many ADSL splitters also cause problems with poor design and imbalance. There are many ADSL forumshttp://forum.kitz.co.uk/http://forums.thinkbroadband.com/threads.phpwith experienced people who can help you with this, attacking the inverter is a waste of energy and will get you nowhere.

author: BoomBrush
author_rank: Contributor
timestamp: October 22, 2018, 11:07:21 pm
content: Quote from: fourtytwo42 on October 22, 2018, 07:12:05 pmThe electrical safety officer was called out due to the dodgy wiring, the fact there are no DC and AC isolators and the connections were at weird angles half hanging out. I was genuinely concerned one of the DC cables was gonna conduct itself onto the metal case. Workmanship quality was really terrible. Also it was a free service so there is a limit to what he provides. Because it's an older system, the electrical certificate requirements were different. According to the Clean Energy Council, as it has no RCM approval this model would be illegal to install after 2015 laws. I've tried without ADSL splitters by plugging the modem directly into the phone line without a home phone with no difference. No we don't have a central splitter outside.All wires are underground. My understanding is that the inverter is unfiltered and causing noise, using the mains wires as giant antennas to conduct emissions into the telecom line (maybe? Let me know if something is up). Since telecom wires run right next to the mains wires, I asked the safety officer if he knew of any clearance requirements between mains and telecom. The phone line patch panel in the garage is directly behind the solar equipment outside so clearances would be tight. Figured it was worth a shot. I suspect moving the wires way out of the way would fix the issue, maybe."so you have to check it yourself"Kinda hard to do when the neighbor in question has a life threatening illness, the last thing she needs to think about is that pesky neighbor bugging her again. I mentioned to a friend that from the houses who've owned this model inverter, some of the occupants have developed brain cancers within the past year or two. My friend mentioned whether the solar equipment could have something to do with the cancers. Now that's a very small sample size and hardly scientific but certainly interesting if the trend continued. Not a fan of the whole "this causes cancer" stuff though.Quote from: fourtytwo42 on October 22, 2018, 07:12:05 pmToo many rick and morty episodes.Thanks for the forum links, will check them out.

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 23, 2018, 04:22:03 am
content: Telecom wiring needs to be 120mm from power cables to provide isolation for safety reasons IIRC.

author: fourtytwo42
author_rank: Super Contributor
timestamp: October 23, 2018, 11:06:01 am
content: Quote from: BoomBrush on October 22, 2018, 11:07:21 pmWhilst not wishing to prolong the agony that is pure rubbish assuming the inverter has passed your countries regulatory requirements I can assure you it will have substantial filters on both the AC & DC sides.In my opinion parallel runs of telephone and power cables need at least 500mm+ of separation to avoid induction impairing ADSL within your house, externally where the runs are liable to be measured in 10's of metres this separation should be at least doubled. All of the telecom wiring needs to be paired and balanced, there must be no open ended taps (unused extensions) bell wires or other paraphernalia upsetting the balance otherwise noise will enter the system. ADSL filters are crucial and should if possible split off the DSL line as close as practicable to the beginning of the internal wiring and if possible be so arranged to also isolate the extension wiring. This may sound excessively pedantic but it is what I had to do to solve my problem similar to yours. Standard ADSL wiring works for standard cases where the attenuation to the exchange is not great and there are no significant noise sources.In my case my attenuation to the exchange is around 55dB so I have to pay attention to detail to get reasonable speed without dropouts. I don't know if you can see your attenuation in your modem stats but if it is approaching this figure then care will be needed.