RE: EMC for automation & control - Electricity utilities (UNIPEDE )
Traditional mechanical wristwatches use an escapement wheel which rotates first clockwise, storing the energy of its momentum into a small spring, then stopping and being accelerated counter-clockwise by the spring, and finally re-storing the energy back into the spring. This brass wheel has little "pegs" pressed into its outer rim. The pegs are steel, and are used to trim the period of the escapement wheel and also to balance the wheel. For those of us who have disassembled watches, you will remember that this part looks like a little wagon wheel, and is usually the part that you break, preventing successful re-assembly of the watch. (I could never get those frogs to work again after re-assembly either.) If the pegs and/or other parts of the watch frame become magnetized, the escapement wheel will be subjected to magnetically induced drag as it attempts to rotate. This will either slow, or even stop, the wheel. I would assume that the magnetic fields encountered in a power generation station would be considerable, especially where the wearer was working very close to pole pieces or even accidently magnetized tools. I wear a cheap, plastic case Casio electronic watch, which I replace at K-Mart when the battery dies (about every 6 years). I periodically get exposed to high power microwave, hold ESD guns and mess around with high current pulse generators. And so far, I have never had the watch affected by any of the stupid stuff I do. BTW, the smell you refer to is Ozone, O3, the hyperactive cousin of Oxygen, O2. Electrical discharges transform the O2 in the surrounding air into O3. It has a subjectively sweet aroma (which probably means your brain cells are dying at an accelerated rate). Regards, Ed From: Robert Macy Subject: RE: EMC for automation & control - Electricity utilities (UNIPEDE ) Date: Wed, 31 Mar 1999 09:36:39 -0800 (PST) To: Mike Hopkins Cc: "'s_doug...@ecrm.com'" , pet...@foxboro.com.au, emc-p...@majordomo.ieee.org > IMHO the magnetic fields go right through the watch case and either > disrupt what's going on or can even magnetize the parts. Either way, the > parts are like "stuck" together and the watch won't run well. > > Also, my father could never wear a watch, a great gift watch always would > stop. The same watch given to my brother, lost ten minutes a day. So when > I got the watch I was happy when it gained a few seconds a month and > lasted for over ten years. Go figure. > > - Robert - > > On Tue, 30 Mar 1999, Mike Hopkins wrote: > > > Very interesting -- my father also worked for what was then New England > > Power and was a substation operator in Tewksbury, MA -- he also went to > > other smaller sub-stations to switch lines in or out for maintence or to > > clear trouble problems and I have similar recollections about the > > electricity "in the air" -- you really could feel it! An interesting side > > note - he could never wear a watch of any kind -- they would either run in > > their own time zones or not work for long at all -- he attributed this to > > the surrounding electric fields, but I've never figured out how that would > > affect a mechanical watch!. > > > > ---End of Original Message- -- Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 List-Post: emc-pstc@listserv.ieee.org Date: 03/31/1999 Time: 12:16:31 Military & Avionics EMC Services Our Specialty Also Environmental / Metrology / Reliability -- - 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: EMC for automation & control - Electricity utilities (UNIPEDE )
For what it's worth, I recall wind-up watches with cases which were labelled "non-magnetic". My assumption is that a magnetic field can affect the movement, although I wouldn't think an AC magnetic field would matter unless it was very strong. A more likely reason for not wearing watches (or jewelry of any kind) is basic safety around live circuits. No jewelry, no neckties (or kerchiefs), and one hand in the pocket are still good rules. Jack Jacob Z. Schanker, P.E. Director of Agency Compliance Microwave Data Systems 175 Science Parkway Rochester, NY 14620 USA +716 242 8454 (voice) +716 241 5590 (fax) jschan...@mdsroc.com -- > -- > From: Mike Hopkins[SMTP:mhopk...@keytek.com] > Sent: Tuesday, March 30, 1999 4:10 PM > To: 's_doug...@ecrm.com'; pet...@foxboro.com.au > Cc: emc-p...@majordomo.ieee.org > Subject: RE: EMC for automation & control - Electricity utilities > (UNIPEDE ) > > Very interesting -- my father also worked for what was then New England > Power and was a substation operator in Tewksbury, MA -- he also went to > other smaller sub-stations to switch lines in or out for maintence or to > clear trouble problems and I have similar recollections about the > electricity "in the air" -- you really could feel it! An interesting side > note - he could never wear a watch of any kind -- they would either run in > their own time zones or not work for long at all -- he attributed this to > the surrounding electric fields, but I've never figured out how that would > affect a mechanical watch!. > > As for ESD (human ESD) as opposed to AC electric or magnetic fields, the > levels of 8kV and 15kV (contact/air) are on the high side. Discharges of a > few kV happen all the time without us even knowing it; discharges that we > feel on a dry day are typically in the 5 to 10kV range, but a 15kV > discharge > from the end of your finger is something you'd remember! Even 10kV is > pretty > uncomfortable.. > > Hope this is helpful, but I doubt it would influence the people who wrote > the standard... > > Mike Hopkins > mhopk...@keytek.com > > > > -Original Message- > > From: s_doug...@ecrm.com [SMTP:s_doug...@ecrm.com] > > Sent: Tuesday, March 30, 1999 10:26 AM > > To: pet...@foxboro.com.au > > Cc: emc-p...@majordomo.ieee.org > > Subject:Re: EMC for automation & control - Electricity utilities > > (UNIPEDE) > > > > Peter, > > > > My father worked for the electric utility for many years. There were > times > > he could take me with him to check on how a substation was working after > > some maintenance or upgrade was performed. From direct experience I can > > tell you that when you enter the substation building, you can quite > often > > feel and smell the electricity in the air. The electrostatic fields that > > build up in these environments can be substantial. Yes, everything > inside > > is well grounded, but when you have thousands of volts running around > big > > copper bus bars, switching systems, transformers, etc. you hear the hum > > and feel the electricity in the air. Back then, I thought it was really > > neat as I did not have the healthy respect that I have since acquired > the > > hard way. > > > > One other thought here, would you want your TV going blink just at the > end > > of the local cricket match or the last quarter of the World Cup > "football" > > game? That could happen if some protective device or overcurrent sensor > > got zapped and caused a shutdown when there was really no system problem > > requiring a shutdown. > > > > > > Scott > > s_doug...@ecrm.com > > > > > > pet...@foxboro.com.au writes: > > >Hi. > > > > > >I've recently been shown a standard published by a European group > called > > >UNIPEDE titled "Automation and Control Apparatus for Generating > Stations > > >and Substations - Electromagnetic Compatibility Immunity Requirements" > - > > >Ref# 23005Ren9523. > > > > > >This standard generally adheres to the same requirements for immunity > as > > >the CE-mark standards, however for ESD it requires 8kV contact and 15kV > > >air > > >for HV substation environments. As is usually the case, there's no > > >rationale provided as to why these levels where chosen (something that > > >really annoys me about most standards). > > > > > >Does anyone have suggestions as to why the authors of the standard > woul
RE: EMC for automation & control - Electricity utilities (UNIPEDE )
IMHO the magnetic fields go right through the watch case and either disrupt what's going on or can even magnetize the parts. Either way, the parts are like "stuck" together and the watch won't run well. Also, my father could never wear a watch, a great gift watch always would stop. The same watch given to my brother, lost ten minutes a day. So when I got the watch I was happy when it gained a few seconds a month and lasted for over ten years. Go figure. - Robert - On Tue, 30 Mar 1999, Mike Hopkins wrote: > Very interesting -- my father also worked for what was then New England > Power and was a substation operator in Tewksbury, MA -- he also went to > other smaller sub-stations to switch lines in or out for maintence or to > clear trouble problems and I have similar recollections about the > electricity "in the air" -- you really could feel it! An interesting side > note - he could never wear a watch of any kind -- they would either run in > their own time zones or not work for long at all -- he attributed this to > the surrounding electric fields, but I've never figured out how that would > affect a mechanical watch!. > - 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: EMC for automation & control - Electricity utilities (UNIPEDE )
Very interesting -- my father also worked for what was then New England Power and was a substation operator in Tewksbury, MA -- he also went to other smaller sub-stations to switch lines in or out for maintence or to clear trouble problems and I have similar recollections about the electricity "in the air" -- you really could feel it! An interesting side note - he could never wear a watch of any kind -- they would either run in their own time zones or not work for long at all -- he attributed this to the surrounding electric fields, but I've never figured out how that would affect a mechanical watch!. As for ESD (human ESD) as opposed to AC electric or magnetic fields, the levels of 8kV and 15kV (contact/air) are on the high side. Discharges of a few kV happen all the time without us even knowing it; discharges that we feel on a dry day are typically in the 5 to 10kV range, but a 15kV discharge from the end of your finger is something you'd remember! Even 10kV is pretty uncomfortable.. Hope this is helpful, but I doubt it would influence the people who wrote the standard... Mike Hopkins mhopk...@keytek.com > -Original Message- > From: s_doug...@ecrm.com [SMTP:s_doug...@ecrm.com] > Sent: Tuesday, March 30, 1999 10:26 AM > To: pet...@foxboro.com.au > Cc: emc-p...@majordomo.ieee.org > Subject: Re: EMC for automation & control - Electricity utilities > (UNIPEDE) > > Peter, > > My father worked for the electric utility for many years. There were times > he could take me with him to check on how a substation was working after > some maintenance or upgrade was performed. From direct experience I can > tell you that when you enter the substation building, you can quite often > feel and smell the electricity in the air. The electrostatic fields that > build up in these environments can be substantial. Yes, everything inside > is well grounded, but when you have thousands of volts running around big > copper bus bars, switching systems, transformers, etc. you hear the hum > and feel the electricity in the air. Back then, I thought it was really > neat as I did not have the healthy respect that I have since acquired the > hard way. > > One other thought here, would you want your TV going blink just at the end > of the local cricket match or the last quarter of the World Cup "football" > game? That could happen if some protective device or overcurrent sensor > got zapped and caused a shutdown when there was really no system problem > requiring a shutdown. > > > Scott > s_doug...@ecrm.com > > > pet...@foxboro.com.au writes: > >Hi. > > > >I've recently been shown a standard published by a European group called > >UNIPEDE titled "Automation and Control Apparatus for Generating Stations > >and Substations - Electromagnetic Compatibility Immunity Requirements" - > >Ref# 23005Ren9523. > > > >This standard generally adheres to the same requirements for immunity as > >the CE-mark standards, however for ESD it requires 8kV contact and 15kV > >air > >for HV substation environments. As is usually the case, there's no > >rationale provided as to why these levels where chosen (something that > >really annoys me about most standards). > > > >Does anyone have suggestions as to why the authors of the standard would > >expect worse ESD conditions in a substation than they seem to expect in > an > >air conditioned, carpeted office? (equipment in environments other than > HV > >substations only need meet 6kV contact, 8kV air according to this > >standard) > > > > > > > >- > >Please note: The views, opinions and information expressed and/or > >contained herein do not necessarily reflect the opinions or views of > >Foxboro, the organisation/s through which this communication was > >transmitted > >nor any other third party, unless explicitly stated so. > > > >Peter Poulos (Hardware Design Engineer) > >Foxboro Australia > >42 McKechnie Drive, Eight Mile Plains, QLD, Australia 4113 > >Tel:+61 (07) 3340 2118 Fax: +61 (07) 3340 2100 > >E-mail:pet...@foxboro.com.au > > > > - > 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: EMC for automation & control - Electricity utilities (UNIPEDE)
Peter, My father worked for the electric utility for many years. There were times he could take me with him to check on how a substation was working after some maintenance or upgrade was performed. From direct experience I can tell you that when you enter the substation building, you can quite often feel and smell the electricity in the air. The electrostatic fields that build up in these environments can be substantial. Yes, everything inside is well grounded, but when you have thousands of volts running around big copper bus bars, switching systems, transformers, etc. you hear the hum and feel the electricity in the air. Back then, I thought it was really neat as I did not have the healthy respect that I have since acquired the hard way. One other thought here, would you want your TV going blink just at the end of the local cricket match or the last quarter of the World Cup "football" game? That could happen if some protective device or overcurrent sensor got zapped and caused a shutdown when there was really no system problem requiring a shutdown. Scott s_doug...@ecrm.com pet...@foxboro.com.au writes: >Hi. > >I've recently been shown a standard published by a European group called >UNIPEDE titled "Automation and Control Apparatus for Generating Stations >and Substations - Electromagnetic Compatibility Immunity Requirements" - >Ref# 23005Ren9523. > >This standard generally adheres to the same requirements for immunity as >the CE-mark standards, however for ESD it requires 8kV contact and 15kV >air >for HV substation environments. As is usually the case, there's no >rationale provided as to why these levels where chosen (something that >really annoys me about most standards). > >Does anyone have suggestions as to why the authors of the standard would >expect worse ESD conditions in a substation than they seem to expect in an >air conditioned, carpeted office? (equipment in environments other than HV >substations only need meet 6kV contact, 8kV air according to this >standard) > > > >- >Please note: The views, opinions and information expressed and/or >contained herein do not necessarily reflect the opinions or views of >Foxboro, the organisation/s through which this communication was >transmitted >nor any other third party, unless explicitly stated so. > >Peter Poulos (Hardware Design Engineer) >Foxboro Australia >42 McKechnie Drive, Eight Mile Plains, QLD, Australia 4113 >Tel:+61 (07) 3340 2118 Fax: +61 (07) 3340 2100 >E-mail:pet...@foxboro.com.au - 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: EMC for automation & control - Electricity utilities (UNIPEDE )
This issue has also been taken to IEC, to be a Generic standard IEC 61000-6-5. It has been distributed as 77/215/CD. In this draft the ESD has been corrected to 6 kV/8 kV for all. Other requirements than the normal CE-requirements do apply. You may want to contact your national IEC 77 committee to get a copy. regards, Ari > -Original Message- > From: EXT Peter Poulos [mailto:pet...@foxboro.com.au] > Sent: Tuesday, March 30, 1999 5:54 AM > To: emc-p...@ieee.org > Subject: EMC for automation & control - Electricity utilities > (UNIPEDE) > > > Hi. > > I've recently been shown a standard published by a European > group called > UNIPEDE titled "Automation and Control Apparatus for > Generating Stations > and Substations - Electromagnetic Compatibility Immunity > Requirements" - > Ref# 23005Ren9523. > > This standard generally adheres to the same requirements for > immunity as > the CE-mark standards, however for ESD it requires 8kV > contact and 15kV air > for HV substation environments. As is usually the case, there's no > rationale provided as to why these levels where chosen (something that > really annoys me about most standards). > > Does anyone have suggestions as to why the authors of the > standard would > expect worse ESD conditions in a substation than they seem to > expect in an > air conditioned, carpeted office? (equipment in environments > other than HV > substations only need meet 6kV contact, 8kV air according to > this standard) > > > > -- > --- > Please note: The views, opinions and information expressed and/or > contained herein do not necessarily reflect the opinions or views of > Foxboro, the organisation/s through which this communication > was transmitted > nor any other third party, unless explicitly stated so. > > Peter Poulos (Hardware Design Engineer) > Foxboro Australia > 42 McKechnie Drive, Eight Mile Plains, QLD, Australia 4113 > Tel:+61 (07) 3340 2118 Fax: +61 (07) 3340 2100 > E-mail:pet...@foxboro.com.au > > - > 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). > <>
