Querobin Posted January 26, 2019 Share Posted January 26, 2019 We installed a solar system in a residential address. The client wanted a net metering but to install a net metering, harmonics should be up to 5% in the electric provider and we are getting higher than 5%.. What should we do. Quote Link to comment Share on other sites More sharing options...
___ Posted January 26, 2019 Share Posted January 26, 2019 I assume you are talking about THD, Total harmonic distortion? NRS097-2-1 does specify that this has to be less than 5%, but I would have expected that any inverter that was certified as NRS compliant would not have this problem... which leads to the next question: What inverter did you use? I'm not an expert in this (wish I was), but as I understand it non-linear loads (that is just about every cheap SMPS-based-appliance in the home) will also affect this, and I'm pretty sure you're not supposed to measure the inverter with the loads. So is this just the inverter on its own? Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 We used a Goodwe Inverter and the resident has a computer business as loads and other appliances.. Also, they has two old UPS. Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 What is the best solution to lower the harmonics? Quote Link to comment Share on other sites More sharing options...
phil.g00 Posted January 28, 2019 Share Posted January 28, 2019 @Querobin What solutions have you already tried? Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 @phil.g00 we are trying to buy our own harmonics tester but we cannot find one even in Hongkong and China.. Is there any that you can offer while we are looking for a tester? Because somehow we don't trust the tester from the electric provider. Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 1 hour ago, Querobin said: We used a Goodwe Inverter and the resident has a computer business as loads and other appliances.. Also, they has two old UPS. What should be the possible way to reduce the harmonics with this loads? Quote Link to comment Share on other sites More sharing options...
phil.g00 Posted January 28, 2019 Share Posted January 28, 2019 (edited) On 2019/01/26 at 8:35 AM, Querobin said: and we are getting higher than 5%. 6 minutes ago, Querobin said: we are trying to buy our own harmonics tester but we cannot find one even in Hongkong and China. How do you know you are exceeding 5% without a test device? Oh I see the electric provider's one, ask to see current calibration cert, otherwise neither of you has one. Edited January 28, 2019 by phil.g00 Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 7 minutes ago, phil.g00 said: Oh I see the electric provider's one, ask to see current calibration cert, otherwise neither of you has one. I'm sorry, what do you mean? current calibration certificate? what's that to do with harmonics? can you please explain further? Thank you.. Quote Link to comment Share on other sites More sharing options...
phil.g00 Posted January 28, 2019 Share Posted January 28, 2019 You said you doubt the accuracy of the electricity provider's harmonic test device. Which is a reasonable statement about any test device if it's out of calibration. 18 minutes ago, Querobin said: Because somehow we don't trust the tester from the electric provider. If his calibration is current what basis have you got for the doubt? Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 Oh okay... Seems clear to me now.. Thank you But what if the tester is calibrated somehow? how can we reduce the harmonics? Quote Link to comment Share on other sites More sharing options...
phil.g00 Posted January 28, 2019 Share Posted January 28, 2019 @Querobin Which brings me back to my question, what have you already tried? Quote Link to comment Share on other sites More sharing options...
Jaws Posted January 28, 2019 Share Posted January 28, 2019 Where are you located ? As the company I work for we have two Elspec G4500 Power Quality analyzers, https://www.elspec-ltd.com/elspec-shop/power-quality-analyzer/portable-power-quality-analyzer/g4500-portable-power-quality-analyzer/ you can rent one from http://www.impactpower.co.za/eform/submit/contact-us but you needs some know how to operate them and interpret the results. They will also come out and do the analyses and specify the correct Harmonic filters. For a residence this might be cost prohibitive ___ 1 Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 28, 2019 Author Share Posted January 28, 2019 @phil.g00 We didn't try anything yet.. Quote Link to comment Share on other sites More sharing options...
phil.g00 Posted January 28, 2019 Share Posted January 28, 2019 (edited) There's a tester: Amprobe ACD-41PQ, I have never used one like this, it looks like it could do the job, $500, you could probably do better shopping around. Look for "power quality analyser" or tester. Let us know how you get on. Edited January 28, 2019 by phil.g00 Quote Link to comment Share on other sites More sharing options...
Querobin Posted January 29, 2019 Author Share Posted January 29, 2019 Alright then. Thank you Quote Link to comment Share on other sites More sharing options...
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