does epmp equipment have built in Ethernet surge protection?

Going to roll out some ePMP2000, the most common surge arrestors I see suppress at 68v or so on all pairs.  Does this supply enough protection for the data lines as they should be suppressed at 8-12v range.

Short answer: yes. This will improve ESD protection of your device.

When talking about ESD, there are very quick voltage inruss (hundreds of V/s) in a very short time. Correct filtering of the input lines and their impedance characteristics will withstand these overvoltage situations, but only for a small fraction of a second. So, for example, reaching 68V on the data lines is not as important as how much time you're at those voltage levels.

If you go for standard get cheap gas discharge tube protections (like the UBNT ones). If you go for premium try to get transient diode based protections; most mid priced solutions are hybrids between technologies. I would not worry as much about voltages.


@EJansson wrote:

Going to roll out some ePMP2000, the most common surge arrestors I see suppress at 68v or so on all pairs.  Does this supply enough protection for the data lines as they should be suppressed at 8-12v range.


surge protection protectors are a small piece of the giant puzzle.     keeping in mind multiple layers of defence against ESD is your best bet.   

first begin with a good antenna and radio grounding system tower topside.    directly ground your antennas and radios to a home run down to the tower ring.   use something heavy like 4 or 2 ga for your home run down.  DO NOT use the tower steel.     ground the radios with a 10 ga line back to your block, and 10 will work for your antennas, but go heavier if you can.     be sure to use shield cat 5e or 6 too.     also, make sure your Ethernet run is longer than your copper run to the ground.    leave a few feet longer than your ground run top side and a few feet longer on the ground as well.     on your ground box, direct ground your jacket shields, switch and everything else.   and add your surge suppressors there as well.        ground your box and switch back to the same ground ring.      done all together, and done right it will be very rare you have a problem with ESD.     surge protection alone won't do you to much good.  

the cambium radios are rated to absorb 1 joule FYI 

ESD will be many thousands of volts, a 68v clamp across all pairs is good for 48v poe.   

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Thanks for the Reply;

1) Good detail on the tower, which I know pretty well,  just wondering you why you don't use the tower steeel as it should have  the lowest resistance (providing no paint).  I been up a lot of  towers that do not use a cable as  you described.  We are not in a high lighting area  though.  

We normally use an arrestor and cable ground on the bottom only if under 150ft after that we add a middle and top ground and a top arrestor.

2) The post was more in regards to client installs with Cambium gear.... ie, do they have enough protection on the ethernet or is it worth putting on an arrestor, finding a  good ground, running running the cable etc?   We do a lot of work in cottage country (lots of rock) so other then connecting to electrical ground  we have very few options.


@EJansson wrote:

Thanks for the Reply;

1) Good detail on the tower, which I know pretty well,  just wondering you why you don't use the tower steeel as it should have  the lowest resistance (providing no paint).  I been up a lot of  towers that do not use a cable as  you described.  We are not in a high lighting area  though.  

We normally use an arrestor and cable ground on the bottom only if under 150ft after that we add a middle and top ground and a top arrestor.

2) The post was more in regards to client installs with Cambium gear.... ie, do they have enough protection on the ethernet or is it worth putting on an arrestor, finding a  good ground, running running the cable etc?   We do a lot of work in cottage country (lots of rock) so other then connecting to electrical ground  we have very few options.

with the tower steel, if you take an ohms meter and make contact with the steel with your probs 3 or 4' apart you'll see a resistance valvue between 5 and 10 depending on the steel, if you do the same test with a peice of copper (or ethernet cable) you'll see a much smaller value.    the towers steel can carry much more current than the ethernet can, but the path potiental is higher in the copper leading it to take the surge in a lot of cases.  

NEC says every outdoor wire heading inside must be arrested.   so by code, you are supposed to in the US.  the power supply, if you smash one and look inside does provide ground contacts to the cable shield and a few compenets inside that i'm asumming provides some ground protection. cambium still recommends using the SSB600 or equivelent. 

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