Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Difference between MCCB and ACB
A circuit breaker is an electrical switching device that can open or close an electric circuit either normally or in case of a fault. Therefore, a circuit breaker is one of the major component of an electrical power system or wiring system.
circuit breaker is usually equipped with a control mechanism which enable it to operate automatically in case of abnormal conditions in the circuit. Since there are different types of load that operate on different voltage levels and require different fault levels. Therefore, according to the operating voltage and fault level, there are various types of circuit breakers available such as MCB (Miniature Circuit Breaker), MCCB (Molded Case Circuit Breaker), ACB (Air Circuit Breaker), OCB (Oil Circuit Breaker), VCB (Vacuum Circuit Breaker), SF6 Circuit Breaker, etc.
In this article, we will highlight the differences between MCCB and ACB by considering various parameters. But before that, let's get a basic understanding of what MCCB and ACB are.
What is MCCB?
MCCB stands for Molded Case Circuit Breaker. It is an automatic electrical switch that provides protection to the electrical appliances from overload, short circuit, instantaneous overcurrent and earth faults, etc.
Basically, the MCCB is an improved version of miniature circuit breaker (MCB). MCCBs are available for protecting the electrical circuits where the current rating is up to 3200 A.
What is ACB?
ACB stands for Air Circuit Breaker. The type of the circuit breaker in which air is used as the arc quenching medium is known as air circuit breaker or ACB.
An air circuit breaker (ACB) is generally used in low voltage applications, where the supply voltage is less than 450 volts. Therefore, the air circuit breakers are widely used in the distribution panels.
The air circuit breakers are suitable to provide short-circuit protection and overcurrent protection to the electric circuits over 600 amperes to 10 kilo-amperes. The primary advantages of the air circuit breakers are high performance, long life and easy to install.
Difference between MCCB and ACB
The following table highlights all the significant differences between MCCB and ACB −
| Basis of Difference | MCCB | ACB |
|---|---|---|
| Full Form | MCCB stands for Molded Case Circuit Breaker. | ACB stands for Air Circuit Breaker. |
| Definition | A molded case circuit breaker (MCCB) is an electrical safety device that protects the electrical circuit from excessive current, which may be caused by overload or short circuit. | An air circuit breaker (ACB) is an electrical switching device that uses air as the arc quenching medium. |
| Current rating | The current rating of MCCB is less. The typical rated current for MCCB is up to 3200 A. | The current rating of ACB is more than MCCB. The range of current for ACB is 600 A to 10 kA. |
| Breaking capacity | The breaking capacity of MCCB is lower than ACB. | ACB has comparatively high breaking capacity. |
| Utilization category | For MCCB, the utilization category is ‘A’. | For ACB, the utilization category is ‘B’. |
| Operation | MCCBs have magnetic or thermalmagnetic operation. | ACBs have thermal-magnetic operation. |
| Adjustment of tripping threshold | The adjustment of tripping threshold of MCCB is easy. | The adjustment of tripping threshold of ACB is little complex than MCCB. |
| Load end compatibility | MCCB is compatible to use at the load end due to its frequent operation with high accuracy. | ACB is not compatible to use at the load end because of its less frequent operation. |
| Accuracy | The accuracy of MCCB is greater than that of ACB. | ACB is comparatively less accurate. |
| Suitability | MCCBs are suitable for low rating LT (Low Tension) panels. | ACBs are suitable for high rating LT panels. |
| Short circuit current rating | The short circuit current rating for MCCB is upto 100 kA. | The short circuit current for ACB is upto 150 kA. |
| Short circuit time | For MCCB, the time required for sensing the short circuit is about 9 milliseconds. | For ACB, the short circuit time is about 30 milliseconds. |
Conclusion
The major difference between an MCCB and an ACB is that the MCCB is a common circuit breaker used at load side for switching and protection, while the ACB is a high rating circuit breaker used in distribution stations and LT control panels.
8K+ Views
