What is the Difference Between Relay and Circuit Breaker?
🆚 Go to Comparative Table 🆚The main difference between a relay and a circuit breaker lies in their functions and the type of signals they handle. Here are the key differences:
- Function: A relay is a switch used for sensing, detecting, and controlling fixed and moving contacts electromagnetically or electrically. It acts as a protective device that alerts the circuit breaker when a fault is detected in the system. On the other hand, a circuit breaker is a non-directional device responsible for acting as a switching device, collecting signals from the relay, and responding accordingly. It is a disconnecting and isolating device that can handle circuits of large amperes of current.
- Directionality: A relay can be directional and non-directional, while a circuit breaker is non-directional only.
- Signal Provision: A relay only provides signals to the circuit breaker in case of fault conditions. A circuit breaker has both the abilities of making and breaking the circuit automatically, manually, or by remote control.
- Amplification: A relay can be used as an amplifier for discrete signals, converting one signal into many, or amplifying a low-voltage signal into a high-voltage signal and vice versa. A circuit breaker cannot act as an amplifier for signals.
- Operating Conditions: A relay operates on low power and voltage input signals, while circuit breakers can be used for low as well as high power circuits, as their operation is automatic on load.
- Protection: Circuit breakers are typically intended for overcurrent protection, while relays can provide both overcurrent and overvoltage protection.
On this pageWhat is the Difference Between Relay and Circuit Breaker? Comparative Table: Relay vs Circuit Breaker
Comparative Table: Relay vs Circuit Breaker
Here is a table comparing the differences between a relay and a circuit breaker:
Feature | Relay | Circuit Breaker |
---|---|---|
Type of device | Sensing and controlling device, acts as a switch | Protective device, acts as a circuit disconnection or isolation |
Operation | Senses fault in the power system and sends a message to the circuit breaker | Breaks the contact after receiving a signal from the relay |
Uses | Switches circuits with small currents | Typically used with large currents |
Amplification | Can amplify signals (e.g., convert low-voltage to high-voltage) | Cannot amplify signals |
Construction | Consists of coils that act as electromagnetic fields and an armature that closes and opens the fixed and moving contacts | Combination of internal electromechanical switch and relay mechanism |
Directionality | Can be directional or non-directional | Non-directional |
Fault Detection | Senses the fault or specified amount of current and sends the signal to the circuit breaker | Detects large changes in current and breaks the circuit automatically, manually, or by remote control |
In summary, a relay is a sensing and controlling device that acts as a switch, while a circuit breaker is a protective device that interrupts an electric circuit to prevent excessive current or short circuits. They serve different purposes and have distinct operational characteristics.
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