Does test equipment in Australia need to comply with EMC emissions standards? - Page 1
Forum section: electronics / general

author: DeanA
author_rank: Regular Contributor
timestamp: March 21, 2021, 04:58:19 am
content: I recently purchased an AC power source for development of LED power supplies.I also need to use the AC power source to do pre compliance EMC emissions testing of the products.Problem is, the radiated emissions of the AC power source is terrible ( [ Specified attachment is not available ]) Blue trace is Ambient, yellow trace is with AC power source on. It will be impossible to do any pre-compliance radiated emissions testing with this supply.Do the mandatory emissions standards in Australia also apply to test equipment such as the AC power source?An earlier version AC power source I have is fine, but new version is switched mode which I guess is the source of the emissions.

author: Mr_Computer
author_rank: Newbie
timestamp: March 22, 2021, 01:30:23 am
content: Just my 2 cent on emissions testing in Aus.I presumed this is in house pre-compliance testing and thus the results will not serve for formal compliance. Such testing is to serve your own purpose of validating that your producthas a chance of passing formal compliance testing and that there is no nasty issues to fix. As long as you can determine that the problematic EMI generated is not from your productitself then that would be good.Question comes down to whether said AC supply will be used for the final product/installation which dictates whether the AC supply is within scope of the testing. I think best to getanother AC supply that is compliant if pushing for formal compliance testing. As long as the tester can see that your setup does not produce emissions over the limit in their test chamberthen you're good. Otherwise you will need to convince them that the noise is generated by out of scope equipment and need to provide them an alternative way to see only your product'semissions.

author: DeanA
author_rank: Regular Contributor
timestamp: March 22, 2021, 04:29:28 am
content: Yes, thanks, I understand that.Most electronic equipment sold into Australia needs to comply with mandatory EMC standards to get the RCM mark (same as electronic equipment sold into Europe needs to comply with EMC standards for the CE mark). My question is, if the mandatory EMC standards also apply to commercial laboratory test equipment (I'm guessing it does) such as the AC power source I just purchased?With no load connected this latest model Itech AC power source clearly has radiated emissions well above the AS61000.6.3 limits. An earlier model by BK precision (actually manufactured by Itech) is fine (probably because it's not switch mode like the new model).I'm questioning if it's even legal to sell the newer model here if it clearly fails radiated emissions standards?

author: station240
author_rank: Unknown
timestamp: March 22, 2021, 05:22:35 am
content: Given you're showing 30MHz to 230MHz, that isn't PSU switching noise.It's what 75Mhz or something ?Put a marker at the peak if you want (us) to know the actual frequency.Your new PSU is microcontroller driven, right ? And that is it's internal clock frequency, or part of it's AC signal generator.

author: TimNJ
author_rank: Super Contributor
timestamp: March 22, 2021, 04:20:32 pm
content: Quote from: station240 on March 22, 2021, 05:22:35 amIt is certainly possible to see semiconductor ringing over the tens to hundreds of MHz range. (Maybe 10 - 300MHz as a typical range.) I'm not saying that it definitivelyisthe AC source, but I wouldn't write it off so quickly.We have a Chroma 61503 source, switch-mode arbitrary waveform AC source. Once or twice tried to use it for conducted emissions testing for 400Hz application. Even with LISN and lots of filtering, the noise floor was still much too high. Not sure about radiated emissions.I think most lab equipment is designed to comply with something like IEC 61326-1, which appears to reference CISPR11 (EN55011) with Class A emissions limits. Class A is less stringent than Class B. My point is: Yes, the emissions profile may not be great.

author: DeanA
author_rank: Regular Contributor
timestamp: March 22, 2021, 09:13:59 pm
content: Yes, the emissions peak is at about 67Mhz and it's quite broad band.That doesn't really matter to me where the noise is generated, it's not my product to fix. All I know is the new Itech AC power source has horrible radiated emissions, more than 17db above the AS61000.6.3 limits for commercial, residential and light industrial environments, so I can't use it for pre-compliance testing of the products I'm trying to develop. The earlier model BK9801 (Itech M7321) is fine for that purpose, no appreciable radiated (or conducted) emissions at all. So the new Itech product is not fit for purpose, if it doesn't comply with mandatory EMC requirements it shouldn't be sold here. I'm just trying to determine what the mandatory requirements for test equipment such as this are for Australia ?

author: Mr_Computer
author_rank: Newbie
timestamp: March 23, 2021, 02:03:40 am
content: Here is a useful link to a guide from ACMA on how to determine applicable EMC standards for different products. Found this very useful when trying to figure what standards are applicable.According to it compliance to IEC 61326-1 and CISPR11 sounds right.https://www.acma.gov.au/sites/default/files/2019-08/ACMA-mandated%20EMC%20standards.pdfCheers

author: DeanA
author_rank: Regular Contributor
timestamp: March 23, 2021, 02:48:37 am
content: Quote from: Mr_Computer on March 23, 2021, 02:03:40 amGreat, thanks very much for that, always had some difficulty trying to work out exactly which standard for which product so that ACMA document should help.Looks like limit for CISPR11 is 50dB(uV/m) for Class A 30-230MHz.