Sometimes stretch the arc using magnetic field and then rely upon the dielectric strength of the SF6  to quench the stretched arc.

They are used to protect DC generators, storage batteries, synchronous converters, or other apparatus from the damage due to the reversal of current in case of short circuit or grounding machines

It is an electromechanical device used to rotate a ratcheting mechanism when power is applied.

These can be rated to safely interrupt up to 300,000 A at 600 V AC

It is composed of three windings; the two outside ones being known as the restraining coils and the inner one as the operating coil. They are so made and connected that the two restraining coils exert a down ward pull, while the operating coil exerts an upward pull.

Differentiation is performed to determine if will be activated.

Any device that is actuated by the instrument transformer or actuating coil, thereby closing the tripping circuit of the circuit breaker in the damaged section of the system

Composed of a strong fiber casing inside of which is enclosed a fuse wire, generally an alloy of lead.

Uses solenoids to control the flow of oils to rams or actuators.

Air blast circuit breaker can be classified as

A circuit breaker must be equipped  with a/an ___ for remote operation

Low voltage circuit breaker having a rated current up to 2500 A with an adjustable trip current in larger ratings.

Its rated current not more than 100 A with a normal tripping and operating in thermal or in thermal magnetic.

A thermal protection switch can protect against

It is taken from the medium or the manner of extinguishing the arc produced when the contacts opened.

It must trip when called upon where current rating is not necessary

Insulators on Circuit Breakers are generally connected in

To limit short circuit current in a power system, ____are used

When supplying a branch circuit with more than one live conductor, each live conductor must be protected by a breaker pole. To ensure that all live conductors are interrupted when any pole trips, a ____ circuit breaker must be used.

It is an electronic component which receives as well as stores electrical energy by using a magnetic field.

It is a rotational version of solenoid

A type of circuit breaker that closes automatically after a delay and used on overhead electric power distribution system to prevent short duration faults from causing sustained outages.

These are used to make circuits carrying enormous currents, and also to break the circuit carrying the fault currents for a few cycles based on feedback from relays.

Part of circuit breaker which separates contacts rapidly in response to high over currents

It is a switch for routing air to any pneumatic device, usually as actuator, allowing a relatively small signal to control a large device.

It is basically a large switching relay designed to open or closed the path of current to the motor terminals

Alternate protection system in case the primary protection fails.

Ability of the relay to close and open contacts at specified magnitudes of circuit current.

Self-destructing to save the downstream equipment being protected.

It must not trip when not supposed to.

An overcurrent protective device with a circuit opening fusible element which break when there is an overcurrent in the circuit.

It is a room or space in a building dedicated to electrical equipment

Triggered when there is a change in apparent impedance due to fault.

Any current in excess of the rated capacity of the equipment of the rated ampacity of the conductor.

Which of the following cannot classified as medium voltage circuit breakers?

It is a manually operated mechanical switch which separates a part of the electrical power system normally at off load condition.

Device No. of: Directional Power Relay

Device No. of: Reverse Phase Relay

Device No. of: Transformer Thermal Relay

Device No. of: Rate of Rise Relay

Device No. of: AC time Overcurrent Relay

Device No. of: AC Circuit Breaker

Device No. of: Exciter Relay

Device No. of: Power factor Relay

Device No. of: Field Application Relay

Device No. of: Ground Protective Relay

Device No. of: AC Directional Overcurrent Relay

Device No. of: Blocking Relay

Device No. of: DC Circuit Breaker

Device No. of: Alarm Relay

Device No. of: Frequency Relay

Most Commonly Used circuit breaker