Type 1 lightning surge protection devices have been meticulously 
engineered to effectively handle the high-energy surges associated with direct lightning strikes. Characterized by a unique high-voltage wave shape denoted as 10/350µs. Installed at the main distribution board or service entry point, they are indispensable protection against the effects of lightning energy and preventing potential catastrophic damage to the main electrical supply.
 

Type 2 surge protection devices are frequently utilized to shield sensitive
electronic devices within a facility, safeguarding against transients with the 8/20µs wave shape. Installed at distribution panels or sub-boards, these devices are designed to address indirect lightning events and power surges from manmade origins such as, tripping of fuses, inductive loads, earth faults and issues with supply voltages. They play a vital role in preventing equipment damage and ensuring uninterrupted operations, making them essential for maintaining operational
integrity and service availability.             
 

Type 3 surge protection devices offer localized protection tailored to individual devices, essential for the safety of people and operations, especially delicate terminal equipment. These are typically smaller, compact devices and are employed for electronic equipment more susceptible to surges. Often built directly into equipment or installed in dado trunking or fused spurs, to protect a fire alarm panel for example. Type 3 devices serve the crucial role as a ‘fine filter’ protecting specific equipment from both 1.2/50µ & 8/20µs wave shapes.
 

In photovoltaic (PV) panel systems, where the vulnerability to high-energy surges, such as those caused by lightning strikes, is a concern, robust protection is achieved through the installation of combined type surge protection devices. Specifically designed for this purpose, combined Type 1/2 devices are strategically integrated into the PV system for each DC ‘string’. Capable of handling the wave shape characteristics 10/350µs & 8/20µs, these devices play a crucial role in intercepting and diverting excessive transient energy. By doing so, they contribute significantly to the resilience of PV panels, ensuring the overall durability and longevity of the solar energy system.
 

10/350µs is the waveshape we associate with direct lightning energy. It take 10µs to reach 90% of its peak value and it decays to 50% of the peak in 350µs. It does sudden and catastrophic damage

8/20µs is the wave shape for switching surges and man made transients. It has a fast rise time and can cause premature wear and tear of electrical and electronic systems.

1.2/50µs is the wave shape that is used for smaller surge events, background ‘noise’ and electromagnetic interference. This can cause failures and damage to sensitive equipment and terminal circuits like fire alarms and nurse or emergency call alarms.