Hello Aboo, The overvoltage category is based on the transients that you are likely to see on the line voltage. Overvoltage Category II assumes that lightning transients will be attenuated by step-down transformers and the impedance within the building's power wiring. However, if you are making a new connection outside the building, that wiring may be exposed again to higher transients. You need to look at the installation of the camera to see how the power wiring is protected. If it has little protection, it probably should be considered Overvoltage Category III. If this is the case, it may also allow transients to come directly into the building wiring through the camera's power.
I have seen problems with this type of installation in lightning prone areas. For example, I don't recommend installing items on the top of a pole in central Florida unless you are ready for direct lightning strikes. Ted Eckert APC-MGE http://www.apc.com/ The items contained in this e-mail reflect the personal opinions of the writer and are only provided for the assistance of the reader. The writer is not speaking in an official capacity for APC-MGE or Schneider Electric. The speaker does not represent APC-MGE's or Schneider Electric's official position on any matter. "aboo, chang" <[email protected] > To Sent by: [email protected] [email protected] cc Subject 04/14/2008 08:30 About overvoltage category AM Hi experts.. I have some questions about overvoltage category.. According to IEC 60664 and 60364 definition, overvoltage III means:Equipment that will be an integral part of the building wiring, overvoltage II means:PLUGGABLE or PERMANENTLY CONNECTED EQUIPMENT that will be supplied from the building wiring. My question is, if a equipment is installed in outdoor location, for instance, a camara installed upon telephone pole, its power is from building soket(plug A type, overvoltage category II), can we also consider this outdoor equpment as overvoltage II? Or we must define it as overvoltage category III because it is outside building and maybe infected by lightning? Thanks Aboo... - ---------------------------------------------------------------- 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
