Jim,
Nice to hear from you again. I hope you and your family are doing well. Our company ships products all over the world and power line voltages and “events” on the power line is one of our biggest problems. We actually have a small team of people in engineering and compliance engineering trying to define the different power line conditions. Ultimately we hope to try to define what conditions we should design our future products to operate or survive and what is beyond practical. What we thought was ok just a few years ago is turning out not to be good enough today. Many of our products are installed by our own people and the first thing they do it measure the line voltage. In about 10% of our installations the line voltage is outside a comfortable operation range of our equipment. We use buck-boost transformers in those cases. Our 230VAC equipment will generally operate properly between 200V and 250V; and beyond that somewhat without damage. We have US customer who will want to use our 230V instruments with 208VAC, which in many installations the voltage is very low; some as low as 180VAC. In some installations, we have seen a nominal line voltage of 250VAC-260VAC (in fact, the 230VAC power in our compliance lab is nominally 252VAC). Knowing that it is normal to see voltage fluctuations of ±10% of nominal, if we install where the nominal voltage is pushing 260VAC, it is possible for our instrument to see 286VAC, which would not be good. So, in those installations, we use buck-boost transformers to boost up and down the voltage so our nominal voltage is around 230VAC and within a safe range. So I guess the short answer to your question is yes, we do see high nominal line voltages in some areas of the world. Other than surges, another big problem we have is with the countless variations in the AC wave shapes which can really screw up motor controllers and heater controls that use zero crossing or phase control. But then again, that is another email all together. The Other Brian ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Goedderz, Jim Sent: Wednesday, June 04, 2008 3:15 PM To: [email protected] Subject: Australia power grid Group, We have some indirect evidence, and some damaged product, that appears to be related to over voltage on the power grid in Australia. The nominal is 240V 50Hz, but we are hearing accounts of voltages as high as 285V. Has anyone else had to deal with damaged product, or can confirm that sections of “down under” may occasionally be running well beyond normal tolerance? Thank you. James Goedderz Product Safety Engineer Tyco/Sensormatic 561.912.6378 _________________________ LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - ---------------------------------------------------------------- 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 [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- 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 [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
