Assistant for protector selection

Lightning can fundamentally affect us in two ways, either by direct impact or through an overvoltage, so a complete lightning protection system is composed of two systems; an external system against direct impacts, and an internal system to counteract the effects produced by overvoltages.

The Technical Application Guide ITC-BT 23 indicates in which situations the use of transient overvoltage protection devices is mandatory, regardless of the power supply system. These cases are:

• Low voltage supply line totally or partially overhead or when the installation includes overhead lines.
• Risk of failure affecting human life (security services, emergency centers, hospitals…).
• Risk of failure affecting the life of the animals (livestock farms, fish farms, etc.).
• Risk of failure affecting public services (computer centers, telecommunication systems, etc.).
• Risk of failure affecting non-interruptible agricultural or industrial activities.
• Risk of foul affecting the installations and equipment of public premises with non-autonomous security services.

Standard 61643-11 indicates that there are 3 types of surge arresters: Type 1, Type 2 and Type 3; differentiated by their energy absorption capacity, the speed of response and the origin of the surge.

In order to know which type of protector we need, according to the regulations, for each specific case it is necessary to take into account whether there are lightning rods, what is the isoceraunic risk of the area and the installation point of the equipment.

The following program is a simplified and automated method of surge arrester selection based on the above mentioned standards in order to make the process more accessible to everyone. In case a more precise calculation is required, or for more complex structures, please contact us.