Circuit Protection Devices Pdf

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.

Circuit protection devices pdf.

The overcurrent protection device ocpd whether a breaker or a fuse defines the circuit. Circuit protection devices protect expensive systems by rapidly disconnecting power to compon ents in the event of an ab normal operating condition. 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. 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. Discrimination with the higher level protection devices must be provided. The purpose is to. Circuit protection at its simplest is the intentional addition of a weak link in an electrical circuit.

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 devices are available in a variety of types shapes and specific current ratings. This is the area of the miniature circuit breaker these circuit breakers are designed to protect final distribution. But before you can size the ocpd you have to determine what load it will supply.

A weak short circuit current a few ka characterises this level. So sizing the ocpd logically comes before sizing the conductors. Zones of fusing and non. 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.

Fuses a fuse is the most common protection device. Protection devices for electrical circuits accomplish two main functions namely consistency as well as protection. Let s start with looking at the order of the calculations. 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.

The two types of circuit protection devices discussed in this chapter are fuses and circuit breakers.