Application Areas:
The low voltage surge arrester Type PBT of Balestro is designed for protection against over-voltage in an electric circuit of general low voltage, which can be used internally or externally.

Constructive Project:
Balestro's low-voltage type PBT surge arresters have a simple and efficient design, incorporating the best conceivable technique of protection against over-voltages. Their active part comprises gas spark gaps which ensure low levels of disruptive voltages in transitory situations (over-voltage) which represents an essential protection containing sensitive electronic circuits in series, with zinc oxide varistors of high thermal capacity, capable of dissipating large quantities of impulse energy resulting in a high degree of impulse current supportability.
The above components are wrapped in porcelain housings with hermetically sealed extremities, guaranteeing perfect impermeability, which in its turn ensures the maintenance of the protection characteristics for many years.

Presentation:

The low-voltage surge arresters are available in three basic features:

A - For direct connection to the low-voltage network without an automatic disconnector (in this case to be installed after the protection against the system's over-currents) normally used in internal installations, built into distribution boxes or internal aerial nets.

B - For installation into external aerial nets with automatic disconnector, which disconnects automatically from the surge arrester system when defective, signaling the failure (through disconnection of the earth terminal). It can also be used in the protection of low-voltage cubicle carriage guides.

C - For direct installation in low-voltage terminals of distribution transformers, with automatic disconnector (generally used by utility companies).