Terminology

Suppressed Voltage - The amount of voltage allowed to pass through a surge suppression device to the equipment connected to the device.
Suppressed Voltage Rating - Determined by UL when specific current and voltage is applied to a surge suppression device. For permanent devices UL tests at 3000A, 6000V while portable devices are tested at 500A, 600V.
Joule Rating - The short duration peak energy rating of a surge suppression device. The higher the joule rating the longer the expected life of the device.
Peak Current - The short duration peak current rating of a surge suppression device.

Types of Temporary Surges

Category A
Long Branch Circuits: more than 10 meters (30 feet) from a Category B location.
Category B
Major Feeders and Short Branch Circuits: distribution panels, industrial bus and feeder systems, heavy appliance circuits, and switches less than 10 meters from a Category B location.
Category C
Outside and Service Entrance: the main service panel and any overhead lines to separate structures.
Source: IEEE 587

◀ Back to Index