Difference Between Relay and Circuit Breaker

The main difference between relay and circuit breaker is that the relay is a device that provides the signal to the circuit breaker in case of any fault in the power system, the circuit breaker is the device that interrupts the signal after receiving the signal from the relay. .

relay vs circuit breaker

Relay is a device or switch used to detect any fault in the power system and send the signal to the circuit breaker. Whereas, circuit breaker is a device or switch that interrupts the signal after detection of any fault in the system.

So a relay is a kind of sensing and switching device. It is only used to detect the fault and send a message to the circuit breaker. It does not imply breaking contact. On the other hand, a circuit breaker is a disconnecting and isolating device. It consists of breaking the connections of the circuit.

A relay can be used to control or select one from a large number of circuits. On the other hand, the circuit breaker can only be used to control a single loop or circuit, like a switch. Also, the relay can function as an amplifier. It can be used to convert one signal to many signals. On the other hand, a circuit breaker cannot be used as an amplifier. It can only receive a signal from the relay and act on it.

A relay works with low power input voltage while; a circuit breaker is an automatic device. It can work at both low and high power and voltage levels. There are different types of relays, for example, Reed relay, hybrid relay, thermal relay, solid state relay, and electromagnetic relay, etc. On the other hand, the different types of breakers are: Minimum Oil Breaker, BOCB Circuit Breaker, SF6 Circuit Breaker, Single Air Circuit Breaker, Axial Blast Circuit Breaker and Vacuum Circuit Breaker, etc.

Relays used to isolate a low voltage circuit from a high voltage one, in microprocessor to control heavy electrical loads, to control multiple circuits, in automatic changeover and as overload relays for motor protection, etc. On the other hand, circuit breakers used in high and low current devices, industrial equipment and applications, household electrical wiring, power plants, electrical machines, and electricity distribution (GND) systems, etc.

Comparison chart

A relay is a switching or sensing and monitoring device used to make and close contacts electromechanically or electronically. It used to detect any fault in the power system and send the signals to the circuit breaker to make or break the circuit. It is a switching device that is used to control the track of electricity. The relay controls the direction of power or electricity in the circuit. We can use a relay to turn a loop on or off instead of manually switching it.

A relay is used to switch a circuit, that is, to activate or deactivate a single circuit among many connected to it. It controls the flow of current through an electromechanical assembly or through the solid state circuit. A relay works with the low power input voltage and ensures complete electrical isolation between the drive and control circuits. The relay can also function as an amplifier. It can be used to convert one signal to many signals. For example, you can convert a low voltage signal to a high voltage signal, or vice versa.

Some essential points must be considered when choosing a relay for a circuit, i.e. type and number of contacts, rated contact voltage, contact sequence, coil current, assembly and mounting, switching time, resistance to radiation and environment.

Types

The relay is divided into different types, for example, reed relay, thermal relay, solid state relay, electromagnetic relay, latching relay, mercury wet relay, polarized relay, ratchet relay, contactor relay, machine tool relay, solid state contactor relay, Buchholz relay, forced guided contact relay, hybrid relay and overload protection relay, etc.

Applications

Relays used to separate a low voltage circuit from a high voltage one, in microprocessor to control heavy electrical loads, to control multiple circuits, in automatic changeover and as overload relays for motor protection, etc.

What is circuit breaker ?

A circuit breaker is a regulating or protective apparatus used to create or break the circuit, either automatically or manually as a result of normal and faulty circumstances, for example, overcurrent and short circuit, etc. It is designed by using electromechanical techniques to prevent short circuit or power surge damage.

The circuit breaker has a solenoid and is held at a defined voltage level to maintain balance in the trip mechanism. In the event of any fault observed in the circuit, for example a short circuit or an overload, the switch is activated and the flow of current is interrupted. The circuit breaker can be turned back on, after solving the problem in the electrical system.

Circuit breakers are available in different packages and sizes according to the requirements of the electrical system. The circuit breaker mechanism can be immersed in an insulating material, such as oil, to improve performance at higher voltage levels. Advanced circuit breakers are used in industries to regulate interruptions through capacitive switching, small inductive currents, and asynchronous switching.

A circuit breaker is an automatic device that can operate at both low and high power and voltage levels. It can be used to control one per circuit, like a switch. A circuit breaker cannot be used as an amplifier. It can only receive a signal from the relay and act on it.

Types

There are also different types of circuit breakers, for example, minimum oil circuit breaker, BOCB circuit breaker, SF6 circuit breaker, axial blast circuit breaker, simple air circuit breaker and vacuum circuit breaker, etc.

Applications

Circuit breakers used in high and low current devices, industrial equipment and applications, electrical wiring in homes, power plants, electrical machines, and electricity distribution (GND) systems, etc.

Key differences

1. A switch that is used as a control and sensing means or apparatus to create and close the circuit electromechanically or electronically is known as a relay. And a protection or control apparatus that is used to automatically or manually make or break contacts as a result of normal and fault conditions, for example, overcurrent and short circuit, etc. is called a circuit breaker.
2. A relay is a type of sensing and switching device. On the other hand, a circuit breaker is a type of disconnecting and isolating device.
3. The relay detects the fault in the power system and sends a message to the circuit breaker in reverse; The circuit breaker breaks contact after receiving a signal from the relay.
4. The relay does not involve breaking the circuit contact. On the other hand, the circuit breaker involved in the breaking of contacts.
5. A relay can be used to control or select one from a large number of circuits. On the other hand, the circuit breaker can be used to control a single circuit, such as a switch.
6. The relay can also function as an amplifier. It can be used to convert one signal to many signals. For example, you can change a low voltage signal to a high voltage one, or vice versa. On the other hand, a circuit breaker cannot be used as an amplifier. It can only receive a signal from the relay and act on it.
7. A relay works on a low power input voltage, while a circuit breaker is an automatic device that can work on either a low voltage level or a high voltage level.
8. There are different types of relays, for example, Reed relay, hybrid relay, thermal relay, solid state relay, and electromagnetic relay, etc. On the other hand, there are also different types of circuit breakers, for example, Minimum Oil Circuit Breaker, BOCB Circuit Breaker, SF6 Circuit Breaker, Axial Blast Circuit Breaker, Single Air Circuit Breaker and Vacuum Circuit Breaker, etc.
9. Relays are used to separate a low-voltage circuit from a high-voltage one, in microprocessor to control heavy electrical loads, to control multiple circuits, in automatic changeover and as overload relays for motor protection, etc. used in high and low current devices, industrial equipment and applications, home electrical wiring, power plants, electrical machines, and electricity distribution (GND) systems, etc.

Final Thought

The above discussion summarizes that the relay is a switching device that is used to detect any fault in the electrical system and send a signal to the circuit breaker. On the other hand, circuit breaker is a switching device that turns current flow on or off according to the message received by the relay.