24 Port Switch CAT5/Ethernet Surge Protection Solutions

[IHaveAQuestionPlease]

Hi all,

I am having issues with a 24 port switch going out in a high-volume lightning area. It is hooked into a surge protector that seems to be doing its job. The switch still powers on but it doesn't see anything hooked into the ports.

I believe the surge is coming through the devices plugged into the ethernet ports of the switch. Is there a product that will provide ethernet surge protection with a large number of ethernet ports in and out, to accommodate a 24 port switch?

I have found products like this that will provide surge protection for a single ethernet line, but that doesn't seem like a practical solution for a full sized switch...

Any ideas?

Thanks!

 

[jsmithepa]

You need a whole-house$$$ protection system am afraid. I recommend a UPS.

 

[IHaveAQuestionPlease]

We are currently using a UPS on the switch but it is not solving the issues we are having with the ports being damaged, which we believe is coming from surging devices plugged in. For example, we have a mesh AP hung outside the building being fed by the switch inside the building. If that mesh AP is struck by lightning it is sending a surge through the CAT5 cable to our switch.

Any other ideas/solutions?

 

[bill001g]

Ethernet ports as part of the standard are magnetically isolated by small transformers. It would almost impossible to for a surge on end equipment to get into ethernet cable. This is part of the safety to prevent even normal power from ever getting into the ethernet. The end equipment would have to take a direct strike and all nothing will protect against a direct hit.

Normally if for example someone plugged a ethernet cable into a power outlet somehow all it does it blow the tiny transformers on that port and you end up with 1 bad port. If you were to find a old style ISDN line that uses rj45 you can blow a port instantly....wonder how I know that

I suspect you just got unlucky and got a failure people just like to blame lighting when what likely happened is the switch was on for months and when it lost power it had a issue that prevented it from coming back up.

 

[IHaveAQuestionPlease]

Ethernet ports as part of the standard are magnetically isolated by small transformers. It would almost impossible to for a surge on end equipment to get into ethernet cable. This is part of the safety to prevent even normal power from ever getting into the ethernet. The end equipment would have to take a direct strike and all nothing will protect against a direct hit.

Normally if for example someone plugged a ethernet cable into a power outlet somehow all it does it blow the tiny transformers on that port and you end up with 1 bad port. If you were to find a old style ISDN line that uses rj45 you can blow a port instantly....wonder how I know that

I suspect you just got unlucky and got a failure people just like to blame lighting when what likely happened is the switch was on for months and when it lost power it had a issue that prevented it from coming back up.

Thanks for the reply Bill! Great information and perspective for me.

 

[westom]

Thanks for the reply Bill! Great information and perspective for me.

Expand on Bill's accurate answer. Most surges are incoming on AC mains - if not connected to earth BEFORE entering a building. Once inside that surge goes hunting for earth destructively via appliances. If a protector is adjacent, then the surge is given even more potentially destructive incoming paths.

In your case, that protector may have made damage easier (givern more wires for the incoming path). Then it found a best path outgoing via Ethernet ports. Surges are a current source. That means anything that might block the surge (ie transformers on ethernet ports) causes the current to create a higher voltage. Voltage continues to increase until it blows through whatever tries to stop it.

Again, anything that would foolishly try to stop a surge only means voltage increases to blow through. The reason a 'whole house' protector (properly earthed) is so effective: it does not foolishly try to stop a surge. Instead is makes a best connection to earth resulting in a near zero voltage.

If any wire in any cable enters the building without connecting to earth, then protection has been compromised. Best protection on coax cable is a hardwire from that coax low impedance (ie 'less than 10 feet') to single point earth ground. Phone line and AC electric cannot connect directly. So a protector must do what that hardwire does better. And again, distance (not wire thickness) is the most important consideration.

This stuff was well understood over 100 years ago. But notice how many (ie a majority) still do not know any of this. Most are only educated by advertising - not by over 100 years of well proven science.

Your investigation starts with the building's single point earth ground ... that must both meet and exceed National Electriacal code and other requirements.