Surge protection devices

Lightning and other surges damages and destroys more and more electronic equipment such as computers, alarm systems, faxes etc. to complete buildings or stations (Radio base stations). Read more below.

Primary protection ED250 (class I,II and III)     Primary protection ED150 (class I,II and III)   Primary protection (air gap) ED100SG
Secondary protection ED50  Secondary protection ED4000  Secondary protection ED80,worlds smalest
N-PE SPD for TT-network ED100 N-PE    Device protection  Test equipment
Signal-/Telephone protection    Data protection (Ethernet cat 5)  Antenna protection (cable-TV etc.)

Overvoltages/Surges/Lightning

Introduction

Today's data equipment has become extremely vulnerable to a phenomenon known as voltage surges and electrical transients. A single IC package can contain over 100,000 memory bits and more than 5,000 logic gates. The high sensitivity due to the small size of the chips used in these packages makes them susceptible to quick degradation from voltage surges and transients. PLCs, MUXs, HUBs, RTUs, SCADA, and Telemetry equipment are especially vulnerable to electrical surges because of their low operation voltages. Many of these components can be damaged beyond repair by an electrical surge as low as 20 volts.

Sources of electrical surges are numerous. The most common is a nearby lightning strike, which will affect nearby data lines through induction. Industrial transients are also significant because they are man made disturbances caused by switching and commuting of electrical motors. The operation of such devices can cause abrupt shifts in the ground potential that can generate a current flow through a nearby data-line in order to equalize the ground potential.

Electrostatic discharge is another form of an electrical surge that can be included in this group. Although often overlooked, (ESD) can potentially be a very harmful transient to fragile data equipment. ESD occurs due to two non-conducting materials rubbing together, causing electrons to transfer from one material to another.

The consequences of electrical surges and transients may be severe. Although the life span of these electrical phenomenon's is very short, the amount of energy that is carried can be extremely high. A typical transient event can last from a few nanoseconds to several milliseconds carrying several thousand volts and at least a few hundred amps of current. These events may cause burnt-line cards, lockups, loss of memory, problems in retrieving data, altered data, garbling...etc. 

The components we use are gas discharge tubes, varistors (MOV) and suppressor diodes. They are used alone or in combinations depending on their behaviour. 

To make a complete protection the mains must first be protected at the entrance by a primary protection. There after a device protection is used to get the voltage protection level to such a low level that it doesn't affect the equipment. The earth connection is very important here. If you use our ED150-275 you get the low residual voltage level in one protection stage.