The Role of Ground Bars Regarding Lightening Strikes on Telecommunications Installations
The integral role of grounding and bonding electrical systems in installations such as telecommunications facilities has recently become more widely recognized. The electrical devices housed in such facilities are usually extremely sensitive to voltage changes, with events such as electrical surges having the potential to damage equipment, harm personnel and prevent optimum operation.
A major reason however, that grounding and bonding are so often spoken about regarding telecommunications facilities, is the fact that in many regions these constructions involve large metal towers. This presents the very real possibility of extreme natural electrical events such as direct lightning strikes.
The occurrence of lightning strikes in telecommunication installations therefore, often results in electrical currents flowing through the steal foundations of the building. This in turn induces voltage surges through avenues such as telecommunications cables, power cables and grounding wires. Such facilities consequently implement complex grounding systems in an attempt to combat these extreme voltage differences, of which the ‘ground bar‘ is a key component.
The Ground Bar Component of Grounding Systems
Ground bars are small copper predrilled panels, which are generally coated in additional metals to allow for better connectivity. This small board is, as stated, one of the integral components utilized in telecommunication grounding systems, as it acts as an extension of the buildings’ ground electrode. This in turn allows for the bonding and consequent grounding of a system at a mutual point.
This joint grounding of electrical components at a set point is of particular importance owing to the fact that, when systems are grounded through numerous different sites in comparison, voltage differences, or ground loops currents, may occur between communication circuits. These currents, depending on their magnitude can cause a host of different problems, the least of these being the interruption of high frequency signals sent out by telecommunication operations.
The Role of Ground Bars in Mitigating the Effects of Lighting Strikes
Although preventing negative effects on telecommunication facilities as a result of lightning strikes is still not entirely possible, the ground bar and associated grounding system, in combination with the lightening grounding system, plays a large role in mitigating equipment damage, personnel injury and operational issues. The damage done however generally depends on factors such as the magnitude of the lightening current and the conductivity of certain building components within the installation.
Generally however, ground bars promote an equipotential plane, or zero voltage, between circuits. This occurs owing to the fact that the ground bar guarantees an electrical conductive path, hence allowing the safe conduction of most voltage currents likely to be imposed on the system.
Although it is stated in this paper that ground bars and associated grounding systems assist telecommunications facilities during surge events such as lightning strikes, very little research has been undertaken comparing different grounding systems. It would therefore be beneficial for this rapidly growing industry to look more closely at the different grounding and bonding options available, in order to improve existing systems and mitigate further damage and disruption to their installations.
