SPD Surge Protective Device T2 3P 3+0 TN-C network In=20kA Imax=40kA Up≤1.35kV SPE340

Protection of three-phase electrical installations in the TN-C system

The SPE340 surge protective device is a T2 type device designed to protect three-phase circuits in TN-C networks - where the protective earth and neutral conductor are combined into a single PEN conductor. The 3P 3+0 design means that the device protects all three phases relative to the common PEN conductor, which corresponds to the specifics of industrial switchboards and buildings powered in a four-wire system with a common return.

The nominal discharge current In = 20 kA defines the surge arrester's ability to absorb repetitive impulse surges with an 8/20 µs waveform - typical for indirect and switching lightning discharges. The maximum discharge current Imax = 40 kA is the limit that the device can absorb once without loss of functionality.

During the triggering of the surge arrester, a peak voltage appears at the terminals of the protected load - its maximum value defines the protection level Up ≤ 1,35 kV. The lower this parameter, the more effective the protection for sensitive electronics.

Operating parameters

The permissible continuous operating voltage Uc = 275 V AC sets the limit for continuous, fault-free operation of the device throughout its service life. The rated operating voltage falls within the range of 240-415 V, which covers standard three-phase voltages encountered in building and industrial installations.

The operating temperature range from -40°C to +85°C allows for use in both outdoor and indoor switchboards - including production halls or pumping stations. The short-circuit strength Isccr = 50 kA guarantees survival under short-circuit conditions until the upstream protection operates.

An important feature is the possibility of installation without an additional back-up fuse for supply current ≤315 A - a design simplification for switchboard manufacturers.

Mechanical construction

The device occupies 3 modules on a DIN TH-35 rail, which corresponds to standard modular switchboard mounting. The dimensions of 96,6 × 53,4 × 71,5 mm fit within the typical format of instrument enclosures.

Screw terminals support single-core and multi-core wires: 1,5-50 mm² and flexible wires: 1,5-35 mm². The tightening torque is 3-3,5 Nm - a parameter important for the certification of standard connections.

The modular design consists of a base and replaceable protection modules - a solution that allows for rapid replacement of a worn element without dismantling the entire device from the DIN rail.

Status signaling is implemented optically - the indicator shows the operating status without the need for additional communication modules. The device is not equipped with a remote signaling contact or integrated backup protection.

The enclosure protection rating is IP2XC - protection against access to hazardous parts with a tool and against water splashes from all directions.

Standard and certificates

The surge arrester meets the T2 requirement class according to IEC 61643, which means the ability to limit surges generated both by switching processes in the power grid and by remote lightning discharges. It is not intended for direct acceptance of lightning strikes - this role is performed by T1 type surge arresters installed behind an external separation system.

The manufacturer declares compliance with the RoHS directive and the absence of SVHC substances according to the REACH regulation - confirming documents are available for download on the manufacturer's website.