Re: Instruments and UL101/IEC 60065 Leakage Current measurements - hi speed
Pete Perkins wrote (in <000801c551a2$7fc843f0$0400a8c0@Pete97219Compaq>) about 'Instruments and UL101/IEC 60065 Leakage Current measurements - hi speed', on Thu, 5 May 2005: >In the context of IEC 60990, hi-speed means circuits that will work >up to 1 MHz - as described in the frequency response curves. Thank you. These days, 'high-speed' could mean 50 GHz plus. -- Regards, John Woodgate, OOO - Own Opinions Only. There are two sides to every question, except 'What is a Moebius strip?' http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Instruments and UL101/IEC 60065 Leakage Current measurements - hi speed
John, et al, In the context of IEC 60990, hi-speed means circuits that will work up to 1 MHz - as described in the frequency response curves. :>) br, Pete Peter E Perkins, PE Principle Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Instruments and UL101/IEC 60065 Leakage Current measurements
Pete Perkins wrote (in <004a01c54f48$33aa3700$0400a8c0@Pete97219Compaq>) about 'Instruments and UL101/IEC 60065 Leakage Current measurements', on Mon, 2 May 2005: > Yes, it is straightforward to build the circuits described in the >standard, but not so trivial for anyone not fairly experienced in the >subtleties of hi-speed circuits. What is 'hi-speed' in this context? -- Regards, John Woodgate, OOO - Own Opinions Only. There are two sides to every question, except 'What is a Moebius strip?' http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Instruments and UL101/IEC 60065 Leakage Current measurements
Brian, et al, Perhaps you would be willing to share some of your DSoscillograms - albeit privately, since the IEEE server strips away attachments. (or some other clever scheme to get them thru). Regarding the construction of the IEC 60990 TC circuits. Yes, it is straightforward to build the circuits described in the standard, but not so trivial for anyone not fairly experienced in the subtleties of hi-speed circuits. IEC 60990 contains a separate section (Annex G) describing the details of properly constructing the circuits and calibrating them for this use. This has been included in the standard from the beginning because of our experience in working with folks who were trying to make proper measurements and having difficulty getting the same results as others. The section was written by a very experienced circuit engineer who built the prototypes for the committee and conducted several show and tell sessions with groups involved in electric shock protection. Anyone building the circuits for themselves should look thru this section of the standard. :>) br, Pete Peter E Perkins, PE Principle Product Safety Engineer PO Box 23427 Tigard, ORe 97281-3427 503/452-1201 fone/fax p.perk...@ieee.org This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwellmcantw...@ieee.org For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Leakage Current Measurements
Ken: Analog meters are inherently good low pass filters and will mask any high frequency components. The same is truefor most DMMs unless they have been specified for higher frequencies. Typically, don't expect much accuracy beyond 100Khz for soem of the best DMMs. You can always use a scope with adequate bandwidth if you susepct high frequency conducted components. That way, you can not only identify whether noise is present but its waveshape. Any changes to make to reduce the noise are readily visible. RF power meterssuffer from the same deficiency unless specifically rated and designed for pulsed waveform measurments. I recall an evaluation done my our Dept of National Defence that found many gross errors in instruments not designed or compensated for narrow pulses. As mentioned on this forum, check for a true rms voltmeter function and assure yourself what kind of accuracy you're getting at the highest frequencies of interest. If you can live with 5-10% error - go for it. Ralph Cameron EMC Consultant and Suppression of Consumer Electronic Equipment ( After sale) - Original Message - From: "Matsuda, Ken" To: Sent: Tuesday, October 03, 2000 3:44 PM Subject: Leakage Current Measurements > > I found something interesting today. While measuring leakage current with a > digital multimeter, I noticed a high amount of leakage. The unit > incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, > I read somewhere that DMMs are some times inaccurate with high frequency > line conducted emissions. Took a old Simpson analog meter (took forever to > figure it out, since I've never touched a analog meter hehehe) and found > measurements that were rather low. The questions is, I'm wondering if UL or > for that matter, any other testing agency actually know about this fact, or > merely fail their clients with incorrect data. > > > Any input on this subject would be appreciated. > > > > Ken > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: jim_bac...@mail.monarch.com > Michael Garretson:pstc_ad...@garretson.org > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > > > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Leakage Current Measurements
If anyone is curious, I have a graph of the frequency response of Annex D using an excel spreadsheet. Contact me off-line. Regards, David. David Gelfand Regulatory Approvals Memotec Communications Inc. Montreal Canada --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Leakage Current Measurements
Dear Ken In EN 60950 and UL1950 appendix D you can find a description on how to measure leakage current and the specifications for the meter. This is taken from another standard which I don't know the number of. If you don't use a meter with the right data you will never know what is the right measurement. Best regards, Kim Boll Jensen i-data, Denmark "Matsuda, Ken" cc: Sent by: Subject: Leakage Current Measurements owner-emc-pstc@ ieee.org 03-10-00 21:44 Please respond to "Matsuda, Ken" I found something interesting today. While measuring leakage current with a digital multimeter, I noticed a high amount of leakage. The unit incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, I read somewhere that DMMs are some times inaccurate with high frequency line conducted emissions. Took a old Simpson analog meter (took forever to figure it out, since I've never touched a analog meter hehehe) and found measurements that were rather low. The questions is, I'm wondering if UL or for that matter, any other testing agency actually know about this fact, or merely fail their clients with incorrect data. Any input on this subject would be appreciated. Ken --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Re: Leakage Current Measurements
Actually, most meters average the waveform, then apply a rote formula converting that average to an rms reading which is more likely to err on the side of too low a reading. For a square wave it will read too high by 6% (actually worked this out, but forgot the actual number, but you have the idea) Then assume that the meter is reading a pulse with twice the amplitude and half the width. The averaging meter will show the same value, but a true rms will show the correct higher value. Then go to eight times higher amplitude with 1/8 pulse width - averaging meter will still read the same, but the true rms will show the correct even higher value. So you see, an averaging meter which has its output slightly adjusted higher to compensate for the difference between a sine wave average and its rms value will usually err on the low side. However, if you check the discrepancy between different shapes one normally encounters, like square, sine, triangle; the error is not that big. The error only really gets big for "spike" waveforms. - Robert - -Original Message- From: Rich Nute To: matsu...@curtisinst.com Cc: emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Tuesday, October 03, 2000 3:04 PM Subject: Re: Leakage Current Measurements > > > > >Hi Ken: > > >> I found something interesting today. While measuring leakage current with a >> digital multimeter, I noticed a high amount of leakage. The unit >> incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, >> I read somewhere that DMMs are some times inaccurate with high frequency >> line conducted emissions. Took a old Simpson analog meter (took forever to >> figure it out, since I've never touched a analog meter hehehe) and found >> measurements that were rather low. The questions is, I'm wondering if UL or >> for that matter, any other testing agency actually know about this fact, or >> merely fail their clients with incorrect data. > >* >The following is Copyrighted 2000 Hewlett-Packard >Company. >* > >When measuring leakage current, and, if the current >waveform is non-sinusoidal, then the measurement >MUST be made with a true rms meter (whether analog >or digital). (The Simpson leakage current meters >are true rms.) > >If a voltmeter is not true rms, it measures the peak >of the waveform, and then reads 0.707 of the number. >So, for any non-sinusoidal waveform, the voltmeter >reading will generally be higher than the rms value, >and will not represent the rms value of the current. > >UL and most other testing houses do understand this >requirement, and ALWAYS use true rms meters. > >For switching-mode power supplies, the leakage >current waveform can be sinusoidal or it can be non- >sinusoidal. The waveshape is dependent on how the >EMC filtering is done. The non-sinusoidal portion >of the waveform is the leakage from the primary >circuits ON THE LOAD SIDE of the rectifier. And, >conversely, the sinusoidal portion of the waveform >is leakage from the SUPPLY SIDE of the rectifier. > >I believe that the non-sinusoidal leakage current >waveform does not exceed the bandwidth of most >voltmeters. The frequencies contained in the non- >linear leakage current waveform do not have >significant current magnitudes above the 40th >harmonic. If we consider all frequencies up to the >40th harmonic of 60 Hz, we have 2400 Hz. Most ac >voltmeters have a bandwidth of at least 10 kHz, >well above 2400 Hz. > >The body network is likewise not particularly >significant to the leakage current measurement. >This is because leakage current is derived from a >source that approaches a current source. For the >sake of this discussion, a current source is a >source that provides a constant current regardless >of load. > >Consider that the source resistance for 0.5 mA >leakage current is 120 volts divided by 0.5 mA, or >240 kohms. Adding 1.5 kohms (the body impedance >model) to 240 kohms gives 0.4969 mA. So, any >reading without the body impedance network is a >very, very slightly pessimistic reading. > >Likewise, the 1.5 kohm resistance and 0.15 uF >capacitance have a pole at about 1 kHz. So, the >capacitor has no effect for frequencies below 1 kHz. > >So, if the non-linear current waveform has lots of >harmonics, then the network will give a lower >reading for those frequencies above 1 kHz. Again, >any reading without the body impedance network is a >very, very slightly pessimistic reading. > >My advice: re-equip your lab with only true rms >meters. > > >Best regards, >Rich > --- This message is from the IE
Re: Leakage Current Measurements
We have had the same experience with the variety of our analogue and digital meters. One solution can be found within the IEC 60990:99 (which is referred to for touch-current measurements e.g. by the newest versions of the IEC 60950 and IEC 60065) and which defines measurement methods for DC and AC sinusoidal or non-sinusoidal waveforms from 15Hz upwards. The interesting part is Annex L, which is about performance and calibration of your measurement network. As the required frequency range of the leakage meter is usually 15Hz to 1MHz (e.g. IEC 60950, Annex D), this Annex L of the IEC 60990 lists tables with input and transfer impedances for a selection of frequencies that make it rather easy to verify the adequacy of your equipment. When using a True-RMS meter for the measurement of switching type power supplies that are operating at frequencies in the range of 100kHz it must also be ensured that the meter is capable to cover that. Many so-called True RMS meters on the market reach up to only 5kHz, crest factors of 2 or 3. /Randolf The IEC 60990 Rich Nute cc: emc-p...@majordomo.ieee.org Sent by: Subject: Re: Leakage Current Measurements owner-emc-pst c...@ieee.org 04.10.00 06:41 Please respond to Rich Nute Hi Ken: > I found something interesting today. While measuring leakage current with a > digital multimeter, I noticed a high amount of leakage. The unit > incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, > I read somewhere that DMMs are some times inaccurate with high frequency > line conducted emissions. Took a old Simpson analog meter (took forever to > figure it out, since I've never touched a analog meter hehehe) and found > measurements that were rather low. The questions is, I'm wondering if UL or > for that matter, any other testing agency actually know about this fact, or > merely fail their clients with incorrect data. * The following is Copyrighted 2000 Hewlett-Packard Company. * When measuring leakage current, and, if the current waveform is non-sinusoidal, then the measurement MUST be made with a true rms meter (whether analog or digital). (The Simpson leakage current meters are true rms.) If a voltmeter is not true rms, it measures the peak of the waveform, and then reads 0.707 of the number. So, for any non-sinusoidal waveform, the voltmeter reading will generally be higher than the rms value, and will not represent the rms value of the current. UL and most other testing houses do understand this requirement, and ALWAYS use true rms meters. For switching-mode power supplies, the leakage current waveform can be sinusoidal or it can be non- sinusoidal. The waveshape is dependent on how the EMC filtering is done. The non-sinusoidal portion of the waveform is the leakage from the primary circuits ON THE LOAD SIDE of the rectifier. And, conversely, the sinusoidal portion of the waveform is leakage from the SUPPLY SIDE of the rectifier. I believe that the non-sinusoidal leakage current waveform does not exceed the bandwidth of most voltmeters. The frequencies contained in the non- linear leakage current waveform do not have significant current magnitudes above the 40th harmonic. If we consider all frequencies up to the 40th harmonic of 60 Hz, we have 2400 Hz. Most ac voltmeters have a bandwidth of at least 10 kHz, wel
Re: Leakage Current Measurements
Hi Ken: > I found something interesting today. While measuring leakage current with a > digital multimeter, I noticed a high amount of leakage. The unit > incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, > I read somewhere that DMMs are some times inaccurate with high frequency > line conducted emissions. Took a old Simpson analog meter (took forever to > figure it out, since I've never touched a analog meter hehehe) and found > measurements that were rather low. The questions is, I'm wondering if UL or > for that matter, any other testing agency actually know about this fact, or > merely fail their clients with incorrect data. * The following is Copyrighted 2000 Hewlett-Packard Company. * When measuring leakage current, and, if the current waveform is non-sinusoidal, then the measurement MUST be made with a true rms meter (whether analog or digital). (The Simpson leakage current meters are true rms.) If a voltmeter is not true rms, it measures the peak of the waveform, and then reads 0.707 of the number. So, for any non-sinusoidal waveform, the voltmeter reading will generally be higher than the rms value, and will not represent the rms value of the current. UL and most other testing houses do understand this requirement, and ALWAYS use true rms meters. For switching-mode power supplies, the leakage current waveform can be sinusoidal or it can be non- sinusoidal. The waveshape is dependent on how the EMC filtering is done. The non-sinusoidal portion of the waveform is the leakage from the primary circuits ON THE LOAD SIDE of the rectifier. And, conversely, the sinusoidal portion of the waveform is leakage from the SUPPLY SIDE of the rectifier. I believe that the non-sinusoidal leakage current waveform does not exceed the bandwidth of most voltmeters. The frequencies contained in the non- linear leakage current waveform do not have significant current magnitudes above the 40th harmonic. If we consider all frequencies up to the 40th harmonic of 60 Hz, we have 2400 Hz. Most ac voltmeters have a bandwidth of at least 10 kHz, well above 2400 Hz. The body network is likewise not particularly significant to the leakage current measurement. This is because leakage current is derived from a source that approaches a current source. For the sake of this discussion, a current source is a source that provides a constant current regardless of load. Consider that the source resistance for 0.5 mA leakage current is 120 volts divided by 0.5 mA, or 240 kohms. Adding 1.5 kohms (the body impedance model) to 240 kohms gives 0.4969 mA. So, any reading without the body impedance network is a very, very slightly pessimistic reading. Likewise, the 1.5 kohm resistance and 0.15 uF capacitance have a pole at about 1 kHz. So, the capacitor has no effect for frequencies below 1 kHz. So, if the non-linear current waveform has lots of harmonics, then the network will give a lower reading for those frequencies above 1 kHz. Again, any reading without the body impedance network is a very, very slightly pessimistic reading. My advice: re-equip your lab with only true rms meters. Best regards, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Leakage Current Measurements
You need to add a network in series with any meter that isn't specifically a "leakage current meter". This human body network model is typically a 1500 ohm resistor in parallel with a 0.15uF cap. Obviously without it you get a very much higher reading than with it. If you did have that network in your DMM measurement, then bandwidth is a likely culprit, and some standards include a frequency response spec that the meter has to meet. I always just use a special purpose leakage current meter. Regards, Jim Eichner Sr. Regulatory Compliance Engineer Mobile Markets Xantrex Technology Inc. Email: jim.eich...@xantrex.com Website: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. -Original Message- From: Matsuda, Ken [mailto:matsu...@curtisinst.com] Sent: Tuesday, October 03, 2000 12:45 PM To: emc-p...@majordomo.ieee.org Subject: Leakage Current Measurements I found something interesting today. While measuring leakage current with a digital multimeter, I noticed a high amount of leakage. The unit incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, I read somewhere that DMMs are some times inaccurate with high frequency line conducted emissions. Took a old Simpson analog meter (took forever to figure it out, since I've never touched a analog meter hehehe) and found measurements that were rather low. The questions is, I'm wondering if UL or for that matter, any other testing agency actually know about this fact, or merely fail their clients with incorrect data. Any input on this subject would be appreciated. Ken --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
Leakage Current Measurements
I found something interesting today. While measuring leakage current with a digital multimeter, I noticed a high amount of leakage. The unit incorporates a switching power supply, with some EMI/EMC circuitry. Anyhow, I read somewhere that DMMs are some times inaccurate with high frequency line conducted emissions. Took a old Simpson analog meter (took forever to figure it out, since I've never touched a analog meter hehehe) and found measurements that were rather low. The questions is, I'm wondering if UL or for that matter, any other testing agency actually know about this fact, or merely fail their clients with incorrect data. Any input on this subject would be appreciated. Ken --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson:pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
RE: Leakage Current Measurements
Frank, I we limit the discussion to the measuring instrument circuit found in Figure D.1 of EN 60950, you see a relatively large capacitance on the input of the circuit followed by a little resistance and a rectifier bridge. The "meter" is then described as a 0 mA - 1 mA moving coil movement. I estimate that the circuit begins to roll-off at about 700 Hz, but there is one sensitivity check at 5 kHz. I would guess that the Simpson can perform at least as well as this. This circuit does not employ the traditional Volt-Ohm Meter (VOM) device that folks sometimes confuse with an analog meter movement. My understanding is that the intent is to only measure "line frequency" related leakage current and it really shouldn't matter. Other standards (e.g. EN61010) take into consideration the higher frequencies and even RF frequencies but for the most part the industrial and commercial equipment standards do not. The difficulty I had was in convincing the inspector that a DVM was acceptable, not because of frequency response but for the aliasing problem found in some DVMs. Doug -Original Message- From: FRANK GOTO [mailto:go...@ul.com] Sent: Wednesday, March 17, 1999 5:00 PM To: emc-p...@ieee.org Subject: RE: Leakage Current Measurements Interesting. During an audit of the facilities of a former employer, the auditor specifically requested that we didn't use the Simpson 228 for EN60950 because of the roll-off of the analog movement above 100Hz. The suggested fix was to build the network as described in the standard, with a high frequency true RMS digital meter. Frank F. Goto - Original Text From: "POWELL, DOUG" , on 3/17/99 12:58 PM: Peter, We use a fixture described in the EN 60950, IEC 61010 or EN50178 standards along with an analog meter movement, as described in the standard. The reason for the analog meter, according to the inspector is that many of the digital meters have an aliasing problem at low frequencies. However in the last few years he/they have been accepting the readings of any digital meter with "true RMS" capability, owing to the fact that many of the commercial systems are also not digital. So far this approach has worked just fine for the LGA Nurnberg and CSA. == Doug Powell, Compliance Engineer Advanced Energy Industries, Inc. Fort Collins, Colorado USA doug.pow...@aei.com www.advanced-energy.com == - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
Hi Frank: > Interesting. During an audit of the facilities of a former employer, the > auditor specifically requested that we didn't use the Simpson 228 for > EN60950 because of the roll-off of the analog movement above 100Hz. The > suggested fix was to build the network as described in the standard, with a > high frequency true RMS digital meter. Analog (D'Arsonval) meter movements are dc devices. AC input is rectified and applied to the meter movement. Any roll-off is a function of the frequency response of the rectifier circuit, not the analog movement (since it only sees dc). Furthermore, the network has a built-in roll-off such that very little high frequency energy is actually applied to the measuring device. If your auditor had applied a constant voltage, variable frequency ac source to the Simpson 228, he would indeed see a roll-off, the one that is due to the frequency compensation network specified in IEC 990. He would see exactly the same roll-off with the discrete network and a wide-bandwidth true-RMS digital meter. Best regards, Rich ps: I do not understand the source of leakage current that is other than the mains frequency. In a switching-mode power supply, virtually all of the high-frequency currents are returned to the source via the EMC filter. Are there other sources that are multiples (harmonics) of the mains frequency? - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
Interesting. During an audit of the facilities of a former employer, the auditor specifically requested that we didn't use the Simpson 228 for EN60950 because of the roll-off of the analog movement above 100Hz. The suggested fix was to build the network as described in the standard, with a high frequency true RMS digital meter. Frank F. Goto - Original Text From: "POWELL, DOUG" , on 3/17/99 12:58 PM: Peter, We use a fixture described in the EN 60950, IEC 61010 or EN50178 standards along with an analog meter movement, as described in the standard. The reason for the analog meter, according to the inspector is that many of the digital meters have an aliasing problem at low frequencies. However in the last few years he/they have been accepting the readings of any digital meter with "true RMS" capability, owing to the fact that many of the commercial systems are also not digital. So far this approach has worked just fine for the LGA Nurnberg and CSA. == Doug Powell, Compliance Engineer Advanced Energy Industries, Inc. Fort Collins, Colorado USA doug.pow...@aei.com www.advanced-energy.com == -Original Message- From: pe...@itl.co.il [mailto:pe...@itl.co.il] Sent: Thursday, March 11, 1999 3:28 PM To: emc-p...@ieee.org Subject: Leakage Current Measurements Dear All Safety Engineers/Technicians, I would like to make a survey of what test equipment (multimeter, scope, etc.) you or your friendly test house use to measure the voltage during the leakage current measurements in UL1950/EN 60 950. WE USE: OUR THIRD PARTY TEST HOUSE USES: PETER S. MERGUERIAN MANAGING DIRECTOR PRODUCT TESTING DIVISION I.T.L. (PRODUCT TESTING) LTD. HACHAROSHET 26, P.O.B. 211 OR YEHUDA 60251, ISRAEL TEL: 972-3-5339022 FAX: 972-3-5339019 E-MAIL: pe...@itl.co.il Visit our Website: http://www.itl.co.il - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
Peter, We use a fixture described in the EN 60950, IEC 61010 or EN50178 standards along with an analog meter movement, as described in the standard. The reason for the analog meter, according to the inspector is that many of the digital meters have an aliasing problem at low frequencies. However in the last few years he/they have been accepting the readings of any digital meter with "true RMS" capability, owing to the fact that many of the commercial systems are also not digital. So far this approach has worked just fine for the LGA Nurnberg and CSA. == Doug Powell, Compliance Engineer Advanced Energy Industries, Inc. Fort Collins, Colorado USA doug.pow...@aei.com www.advanced-energy.com == -Original Message- From: pe...@itl.co.il [mailto:pe...@itl.co.il] Sent: Thursday, March 11, 1999 3:28 PM To: emc-p...@ieee.org Subject: Leakage Current Measurements Dear All Safety Engineers/Technicians, I would like to make a survey of what test equipment (multimeter, scope, etc.) you or your friendly test house use to measure the voltage during the leakage current measurements in UL1950/EN 60 950. WE USE: OUR THIRD PARTY TEST HOUSE USES: PETER S. MERGUERIAN MANAGING DIRECTOR PRODUCT TESTING DIVISION I.T.L. (PRODUCT TESTING) LTD. HACHAROSHET 26, P.O.B. 211 OR YEHUDA 60251, ISRAEL TEL: 972-3-5339022 FAX: 972-3-5339019 E-MAIL: pe...@itl.co.il Visit our Website: http://www.itl.co.il - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
> A meter for IEC 60950 may not be adequate for IEC 61010, > especially if the unit under test has a reasonably high > frequency switch mode power supply. The high frequencies generated in a switching mode power supply are negligible in the presence of the mains-frequency leakage current (presuming that the SMPS as even a mediocre EMC filter). Even if high frequencies are present in the leakage current, the various leakage current measurement schemes use a capacitor to shunt the high frequencies around the metering circuit. The body response to electric energy falls off rapidly for frequencies above 1 kHz. At 100 kHz and above, the injury changes from shock to burn, and the limit is 70 mA peak (50 ma rms!). Consequently, the leakage current meters include frequency compensation to account for the body response. Around the turn of the century, D'Arsonval performed an experiment where he lit a 100-watt bulb at a frequency between 10 and 100 kHz with ALL of the current passing through the human body! No injury! Richard Nute San Diego - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
Gentlemen, There are a few leakage meters on the market and the safety standard will determine the model needed. To get the proper model one has to find out if leakage or touch current is needed and what frequency bandwidth is needed. A full capability meter will measure to IEC 990 and can be used for all other standards. A meter for IEC 60950 may not be adequate for IEC 61010, especially if the unit under test has a reasonably high frequency switch mode power supply. We relied on Ergonomics, Inc for guidance and delivery of the proper meter. Their phone is 215 357 5124 and the web site is www.ergonomicsusa.com. Daniel Mis -Original Message- From: me...@aol.com [mailto:me...@aol.com] Sent: Monday, March 15, 1999 7:37 AM To: ri...@sdd.hp.com; jo...@exchange.scotland.ncr.com Cc: pe...@itl.co.il; emc-p...@ieee.org Subject: Re: Leakage Current Measurements ED&D Inc. also offers several Leakage Current Meters specific to different Standards. They are located in Morrisville NC 919-469-9434 Ed - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
Ray, What is the frequency specs for the Fluke 77 which I assume you are using to measure the voltage drop? From: "Russell, Ray" To: "'me...@aol.com'" , ri...@sdd.hp.com, jo...@exchange.scotland.ncr.com Copies to: pe...@itl.co.il, emc-p...@ieee.org Subject: RE: Leakage Current Measurements Date sent: Mon, 15 Mar 1999 11:50:33 -0500 Send reply to: "Russell, Ray" > Greetings, > > I have used the ED&D leakage current for my previous 2 employers. I really > liked it. They were dependable and very easy to use. > > They are also on the web at http://www.productsafet.com/prodsafety/ > > We currently use a test box built in house to the specifications of UL, > found in most UL standards. We use a Fluke 77 as the measurement instrument. > > Ray Russell > > ray_russ...@gast.com > > -Original Message- > From: me...@aol.com [mailto:me...@aol.com] > Sent: Monday, March 15, 1999 7:37 AM > To: ri...@sdd.hp.com; jo...@exchange.scotland.ncr.com > Cc: pe...@itl.co.il; emc-p...@ieee.org > Subject: Re: Leakage Current Measurements > > > ED&D Inc. also offers several Leakage Current Meters specific to different > Standards. They are located in Morrisville NC 919-469-9434 > > Ed > > - > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > > - > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > PETER S. MERGUERIAN MANAGING DIRECTOR PRODUCT TESTING DIVISION I.T.L. (PRODUCT TESTING) LTD. HACHAROSHET 26, P.O.B. 211 OR YEHUDA 60251, ISRAEL TEL: 972-3-5339022 FAX: 972-3-5339019 E-MAIL: pe...@itl.co.il Visit our Website: http://www.itl.co.il - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
Greetings, I have used the ED&D leakage current for my previous 2 employers. I really liked it. They were dependable and very easy to use. They are also on the web at http://www.productsafet.com/prodsafety/ We currently use a test box built in house to the specifications of UL, found in most UL standards. We use a Fluke 77 as the measurement instrument. Ray Russell ray_russ...@gast.com -Original Message- From: me...@aol.com [mailto:me...@aol.com] Sent: Monday, March 15, 1999 7:37 AM To: ri...@sdd.hp.com; jo...@exchange.scotland.ncr.com Cc: pe...@itl.co.il; emc-p...@ieee.org Subject: Re: Leakage Current Measurements ED&D Inc. also offers several Leakage Current Meters specific to different Standards. They are located in Morrisville NC 919-469-9434 Ed - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
ED&D Inc. also offers several Leakage Current Meters specific to different Standards. They are located in Morrisville NC 919-469-9434 Ed - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
> From owner-emc-p...@majordomo.ieee.org Fri Mar 12 02:24:22 PST 1999 > Received: from hpsdlo.sdd.hp.com (hpsdlo-sw.sdd.hp.com [15.26.112.11]) by > hpsdlfsg.sdd.hp.com with ESMTP (8.7.6/8.7.3 TIS 5.0/sdd epg) id CAA28353 for > ; Fri, 12 Mar 1999 02:24:21 -0800 (PST) > Received: from ruebert.ieee.org (ruebert.ieee.org [199.172.136.3]) > by hpsdlo.sdd.hp.com (8.8.6 (PHNE_14041)/8.8.5btis+epg) with ESMTP id > CAA00549 > for ; Fri, 12 Mar 1999 02:24:20 -0800 (PST) > Received: by ruebert.ieee.org (8.8.8/8.8.8) > id EAA14981; Fri, 12 Mar 1999 04:38:08 -0500 (EST) > Message-ID: <286215c2ca1ad211a13500a024535b58424...@eukscpo3.dundee.ncr.com> > From: "Crabb, John" > To: "'pe...@itl.co.il'" , emc-p...@ieee.org > Subject: RE: Leakage Current Measurements > Date: Fri, 12 Mar 1999 09:35:40 - > MIME-Version: 1.0 > X-Mailer: Internet Mail Service (5.0.1460.8) > Content-Type: text/plain > Sender: owner-emc-p...@majordomo.ieee.org > Precedence: bulk > Reply-To: "Crabb, John" > X-Resent-To: Multiple Recipients > X-Listname: emc-pstc > X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org > X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org > X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org > > We use a Yokogawa 3226 Universal Leakage Current Tester > together with a 3227 Test Box. The meter has both an "AC" and > an "AC+DC" current range, and switchable 1K, 1.5K, and 2K > input resistance. The test box has a polarity and an on-off switch to > simplify testing, and has a US mains socket into which we plug the > product to be tested, using a cord with the earth pin cut off, which we > can also readily reverse. > UL and CSA seem quite happy to use this meter when they come here > to review our products. > We also have a Simpson 229-2 which is there to be used if the other > meter is being calibarated, and it gives similar results to > the Yokogawa. > I asked UL to bring their Simson 228 meter here during a recent > investigation, to compare results. It read a little higher than the > Yokogawa, but UL were happy for us to continue using the Yokowawa. > They certainly do not insist on the use of the Simpson 228. > > I had some information on a Hioki Model 3155-01 Leakage Current > Tester, which is claimed to meet the latest IEC 950 requirements, but > I can't readily lay my hands on it. IT WAS EXPENSIVE. > It is a digital meter, could also measure the voltage/current going > to the equipment, and had pluggable networks for 950 and medical > equipment measurements. > > >From time to time when I am doing leakage current measurements, > I check that the results I get ARE VERY SIMILAR to the reading I > get if I just put the meter in series with the ground conductor of the > product. (And they are always almost identical) Could somebody > explain why this much simpler method is not used ? > > John Crabb, Development Excellence (Product Safety) , > NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 > 3XX > E-Mail :john.cr...@scotland.ncr.com > Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus > 6-341-2289. > > > - > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > > - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
Hi Peter, We use a Fluke 8010A to measure current directly, instead of voltage. We have correlated with UL's meters very closely & have had no disagreement with UL, CSA, or TUV engineers. Mike Harris/Teccom co. tecco...@i-cafe.net 707-258-1360/fax 1361 -- > From: Peter Merguerian > To: emc-p...@ieee.org > Subject: Leakage Current Measurements > Date: Thursday, March 11, 1999 2:28 PM > > Dear All Safety Engineers/Technicians, > > I would like to make a survey of what test equipment (multimeter, > scope, etc.) you or your friendly test house use to measure the > voltage during the leakage current measurements in UL1950/EN 60 > 950. > > WE USE: > > OUR THIRD PARTY TEST HOUSE USES: > PETER S. MERGUERIAN > MANAGING DIRECTOR > PRODUCT TESTING DIVISION > I.T.L. (PRODUCT TESTING) LTD. > HACHAROSHET 26, P.O.B. 211 > OR YEHUDA 60251, ISRAEL > > TEL: 972-3-5339022 > FAX: 972-3-5339019 > E-MAIL: pe...@itl.co.il > Visit our Website: http://www.itl.co.il > > - > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Leakage Current Measurements
We use a Yokogawa 3226 Universal Leakage Current Tester together with a 3227 Test Box. The meter has both an "AC" and an "AC+DC" current range, and switchable 1K, 1.5K, and 2K input resistance. The test box has a polarity and an on-off switch to simplify testing, and has a US mains socket into which we plug the product to be tested, using a cord with the earth pin cut off, which we can also readily reverse. UL and CSA seem quite happy to use this meter when they come here to review our products. We also have a Simpson 229-2 which is there to be used if the other meter is being calibarated, and it gives similar results to the Yokogawa. I asked UL to bring their Simson 228 meter here during a recent investigation, to compare results. It read a little higher than the Yokogawa, but UL were happy for us to continue using the Yokowawa. They certainly do not insist on the use of the Simpson 228. I had some information on a Hioki Model 3155-01 Leakage Current Tester, which is claimed to meet the latest IEC 950 requirements, but I can't readily lay my hands on it. IT WAS EXPENSIVE. It is a digital meter, could also measure the voltage/current going to the equipment, and had pluggable networks for 950 and medical equipment measurements. >From time to time when I am doing leakage current measurements, I check that the results I get ARE VERY SIMILAR to the reading I get if I just put the meter in series with the ground conductor of the product. (And they are always almost identical) Could somebody explain why this much simpler method is not used ? John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: Leakage Current Measurements
Peter, We use Simpson model 229-2 even for UL1950 3rd edition and a UL engineer told us that would be fine. However UL themself use model 228 for 3rd edition and 229-2 for 2nd edition. We also use the in-house kit that has been built in accordance with Annex D/G for production line. This is as good as Simpson except is a bit of hardwork and also is very cost effective. Thanks Homi Ahmadi Cortech Systems - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Leakage Current Measurements
Dear All Safety Engineers/Technicians, I would like to make a survey of what test equipment (multimeter, scope, etc.) you or your friendly test house use to measure the voltage during the leakage current measurements in UL1950/EN 60 950. WE USE: OUR THIRD PARTY TEST HOUSE USES: PETER S. MERGUERIAN MANAGING DIRECTOR PRODUCT TESTING DIVISION I.T.L. (PRODUCT TESTING) LTD. HACHAROSHET 26, P.O.B. 211 OR YEHUDA 60251, ISRAEL TEL: 972-3-5339022 FAX: 972-3-5339019 E-MAIL: pe...@itl.co.il Visit our Website: http://www.itl.co.il - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
