MOV is slow and bad for data but power SAD is fast but not robust Gas tube is robust
I use all 3 on my power surge arrestor products. From: Lewis Bergman Sent: Wednesday, May 10, 2017 9:12 AM To: [email protected] Subject: Re: [AFMUG] Suppression Question When I made the decision to the extent possible, eliminate CAT5 powered devices and go all fiber and 48VDC I based it on two things. I found MOV/SAD combination devices for about $15 to protect the DC line compared to about ~$65 at the time for CAT5. Not only that, I found those devices speced faster clamp times. I assume since they did not have to worry about the voltage differentials of the data pairs. Chuck could obviously answer that one. This was a long time ago so I can't say what current pricing would be. I also found after converting to that that we had less, not zero, but less issues with the fiber plus DC with protection setup than the same equipment fed CAT5 POE with surge. We used all DIN mounted stuff. On Wed, May 10, 2017 at 10:02 AM Mike Hammett <[email protected]> wrote: *nods* I was hoping for a more sciencey and bean countery answer. ;-) ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ------------------------------------------------------------------------------ From: [email protected] To: [email protected] Sent: Wednesday, May 10, 2017 9:58:40 AM Subject: Re: [AFMUG] Suppression Question Any exposed conductor will have a voltage induced on it by lightning strikes. Less conductors, less problems. I would think fiber and power would be more robust than ethernet. From: Mike Hammett Sent: Wednesday, May 10, 2017 8:56 AM To: [email protected] Subject: [AFMUG] Suppression Question This question is intended for Chuck and Forest, but I'll accept answers from anyone else qualified. I assume that the costs and complexities of doing surge suppression on a basic 48v DC power cable are much lower than doing so on a cat6 cable, trying to preserve GigE or above. Could you confirm that and perhaps back it up with costs, commentary, etc.? My point is to show that DC+ fiber not only is better for the data ports on both sides, but also for the tower equipment in general by being able to do more effective and less expensive surge suppression on raw DC than Ethernet. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP
