Earth leakage circuit breaker schematic diagrame

Here is a simplified schematic diagram of an Earth Leakage Circuit Breaker (ELCB):

          +---------------+
          |  Live Wire  |
          +---------------+
                  |
                  |
                  v
+---------------+       +---------------+
|  Earth Fault  |       |  Trip Coil  |
|  Detection    |       |  (Relay)    |
+---------------+       +---------------+
                  |
                  |
                  v
+---------------+       +---------------+
|  Time Delay   |       |  Tripping     |
|  (Optional)  |       |  Circuit      |
+---------------+       +---------------+
                  |
                  |
                  v
+---------------+       +---------------+
|  Earth Leakage|       |  Circuit      |
|  Current      |       |  Breaker     |
+---------------+       +---------------+
                  |
                  |
                  v
          +---------------+
          |  Neutral Wire  |
          +---------------+

Here's a brief explanation of each component:

  1. Live Wire: The live wire is the phase wire that carries the alternating current (AC) from the power source.
  2. Earth Fault Detection: This component detects the earth fault current, which is the current that flows to earth when there is a fault in the circuit.
  3. Trip Coil (Relay): When the earth fault current exceeds a certain threshold, the trip coil is energized, which triggers the tripping of the circuit.
  4. Time Delay (Optional): Some ELCBs have a time delay feature, which allows a certain amount of time to elapse before the circuit is tripped. This is useful in cases where a fault is temporary and self-correcting.
  5. Tripping Circuit: The tripping circuit is responsible for disconnecting the power supply to the faulty circuit.
  6. Earth Leakage Current: This is the current that flows to earth when there is a fault in the circuit.
  7. Circuit Breaker: The circuit breaker is the device that breaks the circuit when the earth leakage current exceeds a certain threshold.

The operation of an ELCB is as follows:

  1. The live wire carries the AC current from the power source.
  2. The earth fault detection component monitors the current flowing to earth.
  3. If the earth fault current exceeds a certain threshold, the trip coil is energized.
  4. The trip coil triggers the tripping circuit, which disconnects the power supply to the faulty circuit.
  5. The circuit breaker breaks the circuit, isolating the faulty circuit from the power supply.

ELCBs are designed to detect earth faults, which can occur due to various reasons such as:

By detecting earth faults and tripping the circuit, ELCBs provide a high level of safety and protection against electrical shock and fire hazards.