cgcmgr 0 Posted June 23, 2011 Hi everyone, Hope you can help. Here's my situation. I am sending power and video over direct burial Cat-5 cable to my IP camera. The camera supports Power over Ethernet and utilizes the 802.3af protocol. I'm using a PoE injector to send the power to the camera (also utilizing the 802.3af protocol). The injector sends power over pins 4,5,7, & 8 while sending data over the other pins (1,2,3, & 6). The Cat-5 cable will be outdoors so I need to use Cat-5 Lightning Surge Protectors in case of a lightning strike. This is where I run into a problem. I have come across a surge protector I like, but it comes in two versions, Mode A and Mode B. Mode A protects all 8 pins with 60 volts line to ground. Mode B protects only pins 4,5,7 & 8 60 volts line to ground and protects pins 1,2,3 & 6 7.5 volts line to ground. Which surge protector do I need? Would either work? It seems to me that Mode A is better b/c it protects all pins. Any input? Chris Share this post Link to post Share on other sites
Soundy 1 Posted June 23, 2011 Mode A and B are just two different delivery specs for PoE: mode A provides "phantom power" on the data pairs, while mode B uses the other unused pairs. More details: http://en.wikipedia.org/wiki/Power_over_Ethernet#Powering_devices If your injector is using only mode B (which SHOULD be the case), then you should only need the mode B protector... but if you go to a PoE switch later, it could have issues with the data pairs only having 7.5V suppression, since PoE runs at 42-48VDC. To be safe, I'd go with the mode A unit... Share this post Link to post Share on other sites
cgcmgr 0 Posted June 23, 2011 Mode A and B are just two different delivery specs for PoE: mode A provides "phantom power" on the data pairs, while mode B uses the other unused pairs. More details: http://en.wikipedia.org/wiki/Power_over_Ethernet#Powering_devices If your injector is using only mode B (which SHOULD be the case), then you should only need the mode B protector... but if you go to a PoE switch later, it could have issues with the data pairs only having 7.5V suppression, since PoE runs at 42-48VDC. To be safe, I'd go with the mode A unit... Thanks for the prompt answer! Share this post Link to post Share on other sites
