Bourns, 1840 Surge Protector 12 V Maximum Voltage Rating 20kA Maximum Surge Current Signal & Data Line Protector

Bourns1800 Series Signal and data line Protection Devices (SPD) have low peak clamping voltage even during severe current surges and the ability to repeatedly protect against high surge currents up to rated limits
1800 Series SPDs are convenient in mounting and grounding to any flat surface or to DIN-1 (TS-32) or DIN-3 (TS-35) rail
Cable shields are passed through and may be either grounded or arc-protected to ground
They have vibration-resistant screw-type clamp terminals and flame-resistant epoxy-filled housing
Applications include Computers, Data communication, Instrumentation, Broadcasting and Industrial controls

Surge Protection Devices, SPDs (DIN-rail)

Voltage surges, often referred to as spikes or transients are typically caused by switching of fluorescent lights, fuses blowing or nearby lightning activity. The worst voltage surges are usually caused by lightning and can reach up to 6000V, with current surges of over 3000A. The maximum size of the voltage and current surges depends on the location within the building's wiring system. BS7671: 2011 Amendment 1 Sections 443 and 534 cover risk assessment and provides guidance on protection of electronic equipment for installation engineers to follow. The fullest information on lightning and surge protection comes from the BSEN 62305 series of standards.