What is the major difference between ACB and MCCB?

Answer 1

MCB (Miniature Circuit Breaker)

Characteristics

• Rated current not more than 100 A.
• Trip characteristics normally not adjustable.
• Thermal or thermal-magnetic operation.

MCCB (Moulded Case Circuit Breaker)

Characteristics

• Rated current up to 1000 A.
• Trip current may be adjustable.
• Thermal or thermal-magnetic operation.

RCCB(Residual Current Circuit Breaker)

Characteristics

• Phase (line) and Neutral both wires connected through RCD.
• It trips the circuit when there is earth fault current.
• The amount of current flows through the phase (line) should return through neutral .
• It detects by RCD. any mismatch between two currents flowing through phase and neutral detect by -RCD and trip the circuit within 30Miliseconed.
• If a house has an earth system connected to an earth rod and not the main incoming cable, then it must have all circuits protected by an RCD (because u mite not be able to get enough fault current to trip a MCB)
• RCDs are an extremely effective form of shock protection

The most widely used are 30 mA (milliamp) and 100 mA devices. A current flow of 30 mA (or 0.03 amps) is sufficiently small that it makes it very difficult to receive a dangerous shock. Even 100 mA is a relatively small figure when compared to the current that may flow in an earth fault without such protection (hundred of amps)

A 300/500 mA RCCB may be used where only fire protection is required. eg., on lighting circuits, where the risk of electric shock is small.

Answer 2

1 : ACB by definition is Air Circuit Breaker - which means, the air gap developed in between the fixed & movable contacts act as insulation. However, the use of such circuit breaker is not much nowadays due to various drawbacks.

2 : MCCB by definition is Miniature Coil Circuit breaker. The contacts are released with the application of desired voltage to the coil controlling the movement of the contacts.

Answer 3

MCCB (Moulded Case Circuit Breaker)

Characteristics

Rated current up to 1000 A.

Trip current may be adjustable.

Thermal or thermal-magnetic operation.

RCCB(Residual Current Circuit Breaker)

Characteristics

Phase (line) and Neutral both wires connected through RCD.

It trips the circuit when there is earth fault current.

The amount of current flows through the phase (line) should return through neutral .

It detects by RCD. any mismatch between two currents flowing through phase and neutral detect by -RCD and trip the circuit within 30Miliseconed.

If a house has an earth system connected to an earth rod and not the main incoming cable, then it must have all circuits protected by an RCD (because u mite not be able to get enough fault current to trip a MCB)

Answer 4

RCD is a general term for Residual Current Device, which then can be devided by many types like RCCB, RCBO, GFCI ets