[PSES] Flame retardancy GB/T 8624-2012

Greetings all, I am attempting to determine equivalency of a flame retardancy rating of B3 in GB/T 8624-2012 to the Flame Spread Indices of ASTM E84. In particular, I really don't know if "B3" is good bad or otherwise. Interestingly, the old idea of flammable vs inflammable has come up and is

Re: [PSES] Flame retardancy GB/T 8624-2012

Hi Doug, GB/T 8624-2012 Equals to; Classification for burning behavior of building materials and products Adopted International Standard No. EN 13501-1:2007 Hope that helps… Chuck McDowell Compliance Specialist Meyer Sound Laboratories Inc. Direct: 510-540-4670 From: Doug Powell

Re: [PSES] Inrush Current

Just curious to why delete the highest and lowest values before taking the average? Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Thursday, August 10, 2017 5:00 AM To: EMC-PSTC@LISTSERV.IEEE.ORG

Re: [PSES] Inrush Current

Because many tests showed that these values are often extreme outliers that affect the average disproportionately. It happens with toroidal transformers; if the previous switch-off left the core magnetized and at switch-on, the current is in the same direction, the core saturates hard and the

Re: [PSES] Inrush Current

Customers sometimes want both the highest peak current and an rms over a defined number of line cycles. If the request is exclusively standards based, John's suggestion works well. You'll need to perform five to ten tests randomly closing on the supply cycle and pick the highest values. If an

[PSES] Inrush Current

Hi We have several times been asked to test Inrush Current and have this function on our Harmonic tester, but it is not defined how it measure and we get very different measurements each time we switch ON the same EUT. I can't find an IEC definition on the measurement other than "peak

Re: [PSES] Inrush Current

Look at Annex B of IEC/EN 61000-3-3. I did a lot of work on this for that Annex and you will often get different results each time, because of differences in how the current is interrupted at the previous switch-off. You do not select a point on the voltage waveform for the switching instant; you

Re: [PSES] Inrush Current

I think it also depends on what your EUT is. Machinery will typically be full of all sorts of loads, motors, transformers, power supplies, computers, inductive, capacitive, etc. The inrush would still be the peak current when the mains is switched on or also when the machine is started as

[PSES] -60Vdc Telecom supply voltage

Dear valued members, can you guide me on nations that uses -60Vdc supply for telecom installations? Appreciate your valued inputs in advance. Best regards, Kannan - This message is from the IEEE Product Safety Engineering Society

Re: [PSES] -60Vdc Telecom supply voltage

Hello Kannan, As far as I know it was used in Russia, however they switch now to 48VDC. In deed there are many different systems and somewhere they might still use 60VDC. Maybe also in some other ex-Soviet Union countries. Best regards, Bostjan From: Kannan Dhamodaran

Re: [PSES] Inrush Current

Well, no-one has challenged Annex B since it was first included in the standard. Note that the standard applies up to 16 A/phase, so no big motors, etc. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates