PART.1
The main difference between circuit breakers and relays
A relay is a switch that is used as a sensing and control device to establish and close contacts electronically or electromechanically. The relay, also used as a protective device, senses the fault signal and sends it to a circuit breaker, which makes a decision to turn the circuit on or off based on the information provided by the relay. Energized coils are connected to relay contacts as moving parts (also known as armatures), while static coils generate the electromagnetic field required by the armature to close or close the contacts for circuit protection.
A circuit breaker is a control and protection device that manually or automatically turns on and off circuits under normal conditions and fault conditions such as short circuit and overcurrent. A relay inside a circuit breaker senses a fault or a specified amount of current and signals it. Signals the electromechanical switch, which opens the contacts and protects the circuit in the event of excessive currents such as overload and short circuits.
There may be a relay in the circuit breaker, but the relay cannot be a circuit breaker.
PART.2
The difference between circuit breakers and relays
PART.3
Different characteristics of relays and circuit breakers
Relays can be directional and non-directional, while circuit breakers can only be non-directional.
Relays only provide signals to circuit breakers under fault conditions, and circuit breakers act as devices that automatically turn circuits on or off based on the information provided by the relay signals.
The relay only perceives the error and notifies the circuit breaker, i.e. the contacts are not opened. Circuit breakers have the ability to turn circuits on and off automatically, manually or remotely by remote control.
A relay is a switch that acts as a sensing device, while a circuit breaker is used for the disconnection and isolation of the circuit. In the case of discrete signals, relays can be used as amplifiers, i.e. converting one signal into multiple signals, amplifying low-voltage signals into high-voltage signals and vice versa. Circuit breakers cannot be used as amplifiers.
Relays operate with low power and low voltage input signals, while circuit breakers can be used in low and high power circuits because it operates automatically on load equipment.
Relays are control devices, while circuit breakers are switchgear.
Relays can be in two different circuits, while circuit breakers can only stop or flow current in the circuit.
The relay cannot stop the arc. There may be mechanisms to detect arc formation and prevent its formation.
Finally, the relay may be included in the circuit breaker, but the circuit breaker is not included in the relay.