Dear Fellow EMC workers, I am trying to get a SMPS to pass this GOST standard and am having a devil of a time getting it done. After 3 days of mitigation testing at our local lab we are still out at the low frequency range 10-60kHz and at 15-50MHz. We pass the Class A limits for CISPR 22 but these GOST limits are far more stringent. The power supply is convection cooled in a IP66 box that is powering a repeater. We have been able to determine that the noise is being generated by the power supply and thus far we are not able to suppress all the low frequency and high frequency conducted noise. I have copied the limit requirements below for your review. Has anyone run into this standard before? Is there something we may be overlooking? We are not using a custom supply, this is an off the shelf supply that we are packaging into a IP66 box. The usual "fixes" didn't seem to work, X and/or Y caps, ferrite beads, inductor. These were applied liberally during the past 3 days. The requirements for EMC of radio equipment in Russia (as well as in several other CIS countries) are set by the standard GOST 30429-96 (Electromagnetic Compatibility of technical equipment. Man-made noise from equipment and apparatus used t6ogether with service receiver systems of civil application. Limits and test methods), according to this standard the following measurement must be done. 1. Conducted Emissions Frequency range Limits, dB(uV) 0.009 MHz - 0.15 MHz U = 90 - 28.9lg(f/0,01) (Quasi-peak) 0.15 MHz - 0.5 MHz U = 66 - 22.7lg(f/0,15) (Quasi-peak) 0.5 MHz - 6 MHz U = 54 - 12.97lg(f/0,5) (Quasi-peak) 6 MHz - 30 MHz U = 40 (Quasi-peak) 30 MHz - 100 MHz U = 48 (Quasi-peak) 40 (Average)
This test is done looking at the emissions from the 220 V power cables, using a LISN 2. Radiated Emissions Frequency range Limits, dB(uV/m) 0.01 MHz - 0.15 MHz E = 60 - 20.4lg(f/0.01) 0.15 MHz - 30 MHz E = 37 - 7.39lg(f/0.15) 30 MHz - 100 MHz E = 36 - 21.0lg(f/0.30) 100 MHz - 1000 MHz E = 25 + 20.0lg(f/100) According to GOST 30429-96 this test is done at 3 meters in frequency range 0.01MHz - 30 MHz and at 1 meter in frequency range 30 MHz - 1000 MHz in the screen room. Any help will be eagerly accepted. Best regards and happy holidays, Lou Guerin Agency Approvals Manager Littlefeet, Inc. [email protected] <mailto:[email protected]> ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
