Circuit Protection Devices Pdf

Protection devices for electrical circuits accomplish two main functions namely consistency as well as protection.

Circuit protection devices pdf. Fuses a fuse is the most common protection device. Let s start with looking at the order of the calculations. Circuit protection devices are available in a variety of types shapes and specific current ratings. Discrimination with the higher level protection devices must be provided.

Fuses a fuse is the simplest circuit protection device. 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. 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. 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 residual current operated circuit breaker with integrated overcurrent protection is a protection device that combines the functionality of rccb and mcb and is used in residential xpole series as well as industrial xeffect series applications. 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. Zones of fusing and non. A weak short circuit current a few ka characterises this level.

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. 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. The protection devices are placed directly upstream of the loads.

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

So sizing the ocpd logically comes before sizing the conductors.