Circuit Protection Devices Pdf

But before you can size the ocpd you have to determine what load it will supply.

Circuit protection devices pdf.

Up protection where the normal protection is provided by some other device such as a circuit breaker or a motor overload trip according to iec standard two classes of lv cartridge fuse are very widely used. A weak short circuit current a few ka characterises this level. Let s start with looking at the order of the calculations. So sizing the ocpd logically comes before sizing the conductors.

The protection devices are placed directly upstream of the loads. Circuit protection devices protect expensive systems by rapidly disconnecting power to compon ents in the event of an ab normal operating condition. Protection is assured through detaching power supply in a circuit through overcurrent protection which removes fire hazards and electrocution additionally the accurate protection may be required to obey with organization principles for some products. The purpose is to.

Circuit protection devices are available in a variety of types shapes and specific current ratings. This link will be broken in the event of a fault whether that s high temperature excessive current or a short circuit in a conductor thus protecting the electrical circuit it s part of from damage. Discrimination with the higher level protection devices must be provided. The overcurrent protection device ocpd whether a breaker or a fuse defines the circuit.

The two types of circuit protection devices discussed in this chapter are fuses and circuit breakers. Even though guidance exists in the form of the various electrical codes the wide variety of product offerings can make the proper selection of circuit protection devices a challenge. Fuses a fuse is the simplest circuit protection device. Protection devices for electrical circuits accomplish two main functions namely consistency as well as protection.

Zones of fusing and non. It derives its name from the latin word fusus meaning to melt fuses have been used almost from the beginning of the use of electricity. Circuit protection at its simplest is the intentional addition of a weak link in an electrical circuit. A fuse is placed in an electrical circuit so tht when current flow exceeds the rating of the fuse it blows or blows out.

For domestic and similar installation type gg for industrial installations type gg gm or am.