Hi,
I am a new member and I came upon this post. I also have the same situation recently. One of our telecom site was hit by lightning. The site already had 2 TVSS units installed, one at the main entrance and one at the point of use(ERICO Brand), where a rectifier unit is installed. Our system ground reading is 4.2 ohms, a value which I presume is still good.
When lightning struck the area, the surge entered our systems through the power lines. The commercial power was cutoff, all other telecom sites in the area have several equipment damages, with several circuit breakers tripping. Only the rectifier I have mentioned above malfunctioned in our building. Upon inspection of the rectifier, no fried components were visible and no burnt smell can be detected. There is however a small regulator circuit board with 11 small components. The two zeners were damaged and the IC transisors broke. The rectifier transformer windings are okay but the rectifier does not have a voltage output.
From my research, lightning induced surges generate a very high voltage magnitude which, if not handled properly, could fry any equipment it comes into contact with. However, there is also one component which is not mentioned always, the frequency. A lightning induced surge also bring about an induction of a very high frequency ranging from 2-50 Mhz.
From my deductions, from the viewpoint of the voltage, I believe that the TVSS was able to suppress the very high magnitude of voltage surge. This can be seen by the normal operation of other equipment connected to our power system and the fact that no fried and burnt equipment can be seen in the malfunctioned rectifier. Or I may be Wrong?
From the frequency standpoint, this is where I have my doubts. Can you enlighten me on the possible effects of high frequency entering an equipment through the power lines? What extend will damage to the equipment be?
Erick
