View Full Version : ODU surge protection

12-30-2004, 03:56 PM
in an installation with IDU-ODU linked with an IF cable using 2 surge arrestors. One next to the oDU and another at the building entry plate, what is the Surge arrestor next to the ODU protecting? ODU or IDU?

01-17-2005, 01:09 PM
Lightning Arrestors is prevents severe potentials variations between the center of the cable and the outer conductor of the cable in the event of a lightning strike.

So, al equipment conected to this coaxial cable will be protected, but, there is no guarantee of 100%.


01-18-2005, 05:47 AM
Thanks Roger, but the Surge Protector ports are not symetrical. One side is labelled 'Protected', I am wondering where this should point to(ODU or IDU) for surge protector installed close to the ODU?

03-30-2005, 10:57 AM

very late reply, but just in case you still have a problem....
The sign on a surge unit named "Protected" means that on this port you have to connect the unit you are trying to protect. So, in your case, where the surge protector is installed at the ODU side, the protected port has to be connected to the ODU.

Look: If the lightning strike will hit directly to the ODU, there is no hope for the ODU anymore. The strike will continue to go towards the IDU and the surge protector on the building/shelter entry point will have a job to eliminate the strike.

If the lightning strike hits the tower, there is a large posibility some of the power will be inducted to the IF cable...in that case, both surge protectors will try to eliminate the strike ( entry point for the IDU, near the ODU for the UDU).

Luckily, the strike hits the top of the tower and not directly the MW ODU equipment.

BUT.... there are always different kind of thinking....when the lightning stikes are on the menu :)