Difference Between Circuit Breaker vs. Isolator

Main Difference

Circuit Breaker and Isolator are the electrical devices used in the grid stations and Power Plants to switch off or switch on the lines. Electricity is very important in our life and we can’t imagine without it. But it may be harmful in case of any fault which may damage the equipment or may harm us. Circuit Breaker and Isolators are basically the devices which are installed in the system to prevent our lives and equipment in case of any fault. Circuit Breaker is auto operated by a relay or by electro-mechanical mechanism while Isolator is manually operated. Circuit Breaker is an on-load device while on the other hand Isolator is an off-load device. It means that the circuit breaker operates when the line is energized and any fault is occurred. While Isolator will be manually operated when it is ensured that the system or line is de-energized.

What is Circuit Breaker?

Circuit breakers are available in different sizes, dimensions, and measurements from tiny devices that safeguard an individual household equipment up to massive switch-gear made to guard high voltage circuits serving a complete town. All circuit breaker devices currently have typical characteristics within their functioning. Despite the fact that specifics differ considerably with regards to the voltage class, current rating, and kind of the circuit breaker. The circuit breaker should identify a problem and fault condition; in reduced voltage circuit breakers normally, this is completed inside the circuit breaker box. Circuit breakers with regard to massive currents or higher voltages are often organized with shielding relay pilot equipment to perfect sense a fault condition and also to function the particular trip opening feature. The particular trip solenoid which produces a latch is generally stimulated with an independent battery, even though some high voltage circuit breakers are generally self-contained along with current transformers, shielding relays as well as an interior manage power supply. When a fault is sensed by the circuit breaker, contacts of the circuit breaker operate to break the connection of the fault area with the circuit and break up the circuit; several mechanically-stored power included inside the circuit breaker is utilized to split up the particular connections, however, some of the power needed could be extracted from the fault current itself. Tiny circuit breakers could be operated by hand, more substantial models possess solenoids in order to trip the process, and electric powered motors to regenerate energy to the springs. The circuit breaker connections should have the load current without having an extreme heating problem, and should definitely endure the temperature of the arc created whenever interruption is in the circuit. Connections are constructed with copper or copper metals, silver alloys along with other extremely conductive products. Support lifetime of the connections is restricted through the breakdown of contact substance because of arcing whilst interrupting the current in the circuit. Some circuits are usually not used when the connections are deteriorated like in molded-case and Miniature circuit breakers however power circuit breakers and high-voltage circuit breakers currently have changeable connections. during short circuits, circuit breakers play a vital role and protect the circuit by heating up or damaging. Usually, circuit breakers have standard current ratings, specific trip settings and time delay operations (usually less than 100 milliseconds). Common types of Circuit Breaker include Low-Voltage Circuit Breaker, Common Trip Breakers, Oil Circuit breakers, Vaccum circuit Breaker, SF6 Circuit breaker, Thermal Magnetic Circuit Breakers, High Voltage Circuit breakers and Medium Voltage Circuit Breakers.

What is Isolator?

An isolator switch is part of an electrical circuit and is most often found in industrial applications. The switch does exactly what its name suggests in that it electrically isolates the circuit or circuits that are connected to it. Such a switch is not used normally as an instrument to turn on/off the circuit in the way that a light switch does. It is off load or no load device. It is mostly found in heavy industry. It is operated to disconnect the electrical system from the main supply for maintenance activities. It is an additional safety device. The trapped charge will be grounded through its ground terminal. It is normally placed after the circuit breaker.

Key Differences

  1. Circuit Breaker is an on-load device while on the other hand Isolator is an off-load device. It means that the circuit breaker operates when the line is energized and any fault is occurred. While Isolator will be manually operated when it is ensured that the system or line is de-energized.
  2. Circuit Breaker is auto operated by a relay or by electro-mechanical mechanism while Isolator is manually operated.
  3. In a system if both the Circuit Breaker and Isolator are installed and any of equipment is needed to be maintained, firstly the circuit breaker will be tripped and then isolator will be operated manually.
  4. When Circuit Breaker trips the circuit, heavy spark is produced which is quenched by the use of quenching medium i.e. SF6, Gas etc. When the Isolator is operated and the equipment is isolated there is no spark produced.

Comparison Video

Author:

Harlon Moss

Harlon currently works as a quality moderator and content writer for Turpy Media. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss or on Pinterest @HarlonMoss

View all posts by Harlon Moss