Overvoltages are transient and impulsive voltages, such as lightning and electrical operations. To protect yourself there are protective devices, or arresters.
- SPD, or surge protection devices (arresters) are created to protect electrical systems and equipment caused by Surge. According to the legislation CEI EN 60664-1 (Insulation coordination for equipment in low voltage systems. Part 1: Principles, requirements and tests) are overvoltages all those voltages which reach a maximum peak higher than the peak of the maximum voltage in permanent regime.
It generally has one short term, below the millisecond, but its amplitude can reach the rated voltage dozens of times of network.
Good impulse withstand is essential in all electrical and electronic equipment and this is why the devices are equipped with systems capable of isolating the parts connected to the phases from the earth.
Insulation depends on the type of equipment, it could be a hundred volts in the case of sensitive electronic devices as well as kilovolts for the protection of an electric motor. If a device is unprotected or the seal fails, the overvoltage spreads through the device and current travels freely through the device.
SENECA's surge protection devices
Seneca has created one series, S400, of voltage arresters among which:
- Type 2 and 3 arresters for industrial power systems
- Protections for control systems, measurement and regulation that can be used in binary and analog circuits, such as pulses, 0..10 Vdc signals and 0 / 4..20 mA current loops
- Surge protections for computer and communication networks (Token Ring, ISDN, DS1, Ethernet, Power over Ethernet, RS232 / 422/485 etc.) with extremely high transmission rate and dispersion capacity.