Not a POE/Network/Camera related story, but lightning related and therefore relevant. Sometimes there is nothing you can do to predetermine an electrons choice of a path to ground. In my early days I worked as a broadcast engineer at a CBS Television network affiliate in severe thunderstorm country. We had a 500’ tower with copper transmission line feeding the VHF antenna. Imagine an 8” copper water line with a 1” copper line down the middle with Teflon spacers at about 4’ intervals. This tower had an intricate grounding system at the base and each of the guy line anchors with a very large lightning rod at the top. Nonetheless, a magnificent storm rolled in one spring afternoon with the typical light and sound show accompaniment. After the rain stopped and the hair had settled back into place we accessed the damaged. The transmitter wouldn’t come back on with a shiny indicator pointing to a fault in the output. Long story short, one of the 8” diameter ½” thick Teflon insulators was melted (the melting point of Teflon is somewhere south of the surface of the sun) and two had been turned into lovely gray dust coating the inside of the outer line. We were down for several days cleaning up the mess, and considered ourselves lucky at that. Lightning!!!
Colin Daniel Network Systems Manager Montana State University 406-994-4981 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler Sent: Friday, August 07, 2015 9:06 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Outdoor PoE If one is following electrical codes/best practices, are these devices needed? That is, externally mounted ethernet devices such as cameras and access points as supposed to be using STP and not UTP cable (providing a solid path to ground). The camera/ap should be grounded at it’s mount point and on the PSE side (switch, injector, etc.), In the case of a switch, it should have a separate ground lug that’s tied into a ground bus-bar. I suspect If you follow the above, these additional devices may not be required. And if the above isn’t being followed, it may be a good idea to chat with an electrical engineer just to make sure your not installing a bunch of potentially deadly lightning rods. :) Jeff From: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" on behalf of Thomas Carter Reply-To: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" Date: Friday, August 7, 2015 at 6:23 AM To: "wireless-lan@listserv.educause.edu<mailto:wireless-lan@listserv.educause.edu>" Subject: Re: [WIRELESS-LAN] Outdoor PoE We haven’t had any problems, but we’ve used these: http://www.l-com.com/surge-protector-outdoor-10-100-1000-base-t-cat6-poe-compatible-lightning-protector-rj45-jacks with great success. They also have a punch down version as well if you want to mess with that. We have them mounted outside with the APs and a good copper ground wire. If you haven’t looked at them, l-com.com has a wide array of antennas, cabling, etc. No connection to them, just a happy customer. Thomas From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Hector J Rios Sent: Thursday, August 6, 2015 8:24 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU> Subject: [WIRELESS-LAN] Outdoor PoE For those doing outdoor wireless, here are two products we have purchased that we have found very useful: Microsemi Outdoor PoE Surge Protector PD-OUT/SP11<https://www.amazon.com/gp/product/B00NMU85PM/ref=od_aui_detailpages00?ie=UTF8&psc=1> http://www.newegg.com/Product/Product.aspx?Item=17B-00A5-00001&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-Surveillance+Accessories-_-17B-00A5-00001&gclid=CIOKgobGlMcCFQmNaQodJ_0C0Q&gclsrc=aw.ds Microsemi PowerDsine 9001GO - PoE injector - 30 Watt http://www.cdw.com/shop/products/Microsemi-PowerDsine-9001GO-PoE-injector-30-Watt/2578417.aspx?cm_cat=GoogleBase&cm_ite=2578417&cm_pla=NA-NA-PWD_NE&cm_ven=ShoppingFeeds&ef_id=VLgjcQAABAHVQD8U:20150806132234:s&gclid=CKyxxczGlMcCFQgtaQodCO8PhQ Regards, Hector Rios Louisiana State University ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
