Hello,
I have a 3 km fiber optic ring for a network for CCTV cameras. In this fiber optic ring I have 10 "nodes". Each node has a POE switch that uses UTP cable to connect to 5 cameras in a star configuration. For example camera 1 is 90 meters to the left of the node, camera 2 is 45 meters to left, camera 3 is right on the node, camera 4 is 45 meters to the right of the node and camera 5 is 90 meters to the right of the node. All cameras are mounted on metal poles.
At first my design consisted on placing one electrode on each pole and use a standard POE surge protector on the camera side grounded to the electrode on the pole, and one POE surge protector on the node side grounded to the electrode on the node's pole.
So basically I have 5 poles on each node, about 45 meters apart, each with its independent electrode, and all that connects between the poles is UTP cable with a max of 24VDC 0.5A load from each camera.
In total we have:
50 poles with its independent electrode
10 nodes, 4 are powered from the same connection to one meter, 3 are connected to another and 3 are connected to another
50 IP POE cameras.
Our client consulted some "expert" and he convinced my client that all electrodes must be bonded together. After bonding the electrodes in a Ring (same path as the fiber optic cable) after a storm we got 16 burned cameras,3 burned nodes, 3 burned UPS units.
I opposed the bonding of all electrodes in the first place, as I think that 45 meters between each of them is more than enough, so bonging is not necessary.
I have been looking around on the internet and NEC to see if I can find something that supports my theory, but so far I have found nothing that supports either bonding them all together or leaving them independent of each other.
So I kindly ask for some advice on this matter. We have a technical dilemma because before bonding all electrodes together, nothing got toasted in almost 2 years and we had had many storms.
Thanks a lot
I have a 3 km fiber optic ring for a network for CCTV cameras. In this fiber optic ring I have 10 "nodes". Each node has a POE switch that uses UTP cable to connect to 5 cameras in a star configuration. For example camera 1 is 90 meters to the left of the node, camera 2 is 45 meters to left, camera 3 is right on the node, camera 4 is 45 meters to the right of the node and camera 5 is 90 meters to the right of the node. All cameras are mounted on metal poles.
At first my design consisted on placing one electrode on each pole and use a standard POE surge protector on the camera side grounded to the electrode on the pole, and one POE surge protector on the node side grounded to the electrode on the node's pole.
So basically I have 5 poles on each node, about 45 meters apart, each with its independent electrode, and all that connects between the poles is UTP cable with a max of 24VDC 0.5A load from each camera.
In total we have:
50 poles with its independent electrode
10 nodes, 4 are powered from the same connection to one meter, 3 are connected to another and 3 are connected to another
50 IP POE cameras.
Our client consulted some "expert" and he convinced my client that all electrodes must be bonded together. After bonding the electrodes in a Ring (same path as the fiber optic cable) after a storm we got 16 burned cameras,3 burned nodes, 3 burned UPS units.
I opposed the bonding of all electrodes in the first place, as I think that 45 meters between each of them is more than enough, so bonging is not necessary.
I have been looking around on the internet and NEC to see if I can find something that supports my theory, but so far I have found nothing that supports either bonding them all together or leaving them independent of each other.
So I kindly ask for some advice on this matter. We have a technical dilemma because before bonding all electrodes together, nothing got toasted in almost 2 years and we had had many storms.
Thanks a lot