Surge protective device ESPAC V T12 12,5/275 1+0 10100120080

Lightning protection in main switchboards

The ESPAC V T12 12,5/275 surge arrester of Type 1+2 (B+C) class is a single-pole surge protection device designed for installation in the main switchboards of residential, office, and industrial buildings. Its single-module width on the TH-35 rail ensures minimal space consumption in the electrical panel - a significant feature when designing compact switchboards.

The device protects the installation against the effects of direct and indirect lightning discharges and switching surges. The impulse current Iimp of 12,5 kA (10/350 µs) allows for use in facilities with LPL III and IV classes - typically in buildings with lightning protection systems of medium protection levels. The rated discharge current of 30 kA (8/20 µs) and peak current of 60 kA provide a safety margin during multiple strikes.

The executing element is a varistor, which translates to a fast response time of just 25 ns. The voltage protection level of 1,5 kV effectively limits the voltage at the terminals of the protected circuit even during strong discharges.

Network compatibility and operating conditions

The arrester is dedicated to TN-S, TN-C, and TN-C-S network systems - the most commonly encountered in buildings powered from low-voltage network transformers. The continuous operating voltage of 275 V AC corresponds to the standard 230 V single-phase network, and the permissible transient overvoltage (TOV) level of 335 V for 5 seconds protects the varistor against overheating in emergency conditions.

The operating temperature range from -40°C to +80°C and ambient humidity of 5-95% allow for use in both heated rooms and outdoor switchboards (maintaining IP20 - indoor installation only). The short-circuit strength of 50 kA guarantees the safe behavior of the device during short circuits near the arrester.

Construction and status signaling

The modular design enables rapid replacement of the worn element without dismantling the entire device - simply disconnect the power and slide the module out of the base. An optical indicator changes color from green to red, informing about the depletion of the varistor and the necessity of module replacement. Thanks to mechanical coding, each module fits only the dedicated arrester - incorrect selection is physically impossible.

The terminals accept both single-core (1-35 mm²) and multi-core (1-25 mm²) wires, as well as busbars in fork or pin versions. Installation is possible in two positions on the TH-35 rail - facilitating cable routing in tight switchboard spaces.

Standard and certification

Production in accordance with PN-EN 61643-11:2012 and IEC 61643-11:2011 standards confirms compliance with European and international requirements for surge protection devices. Integrated thermal protection automatically disconnects the arrester from the network if the permissible temperature or discharge current above Imax is exceeded - eliminating the risk of fire or installation damage.