Circuit breaker testing

A circuit breaker in an electrical substation is a switching device that can be operated manually or automatically for controlling and protecting an electrical power system. It consists of two main contacts: a fixed contact and a moving contact.

The contacts are normally closed and allow current to flow through the circuit.

Circuit breakers protect electrical circuits from damage caused by overcurrent, short circuits, or overload.

They interrupt the flow of current when a fault occurs and restores it when the fault is cleared. Unlike a fuse, which needs to be replaced after one operation, a circuit breaker can be reset and reused multiple times.

Circuit breakers are essential for the safety and reliability of electrical systems. If a fault occurs, circuit breakers can protect people from electrical shocks. Circuit breakers also help prevent equipment damage, fire hazards, and power outages caused by faults. They also allow for selective isolation and switching of different parts of the power system for maintenance and control purposes.

At SMC, we are  convinced that commitment to our customer’s needs is the main driver to grow together, developing the right solutions which help to perform efficient, reliable and accurate tests.



Questions? Doubts? No matter what it is, access the EuroSMC Academy technical documentation section and…unlock a world of knowledge!

The importance of testing Circuit Breakers in electrical substations

Testing circuit breakers in medium and high voltage electrical substations is crucial for several reasons. Firstly, it ensures the safety of the equipment and personnel as circuit breakers are designed to protect the system from damage caused by overloads or short circuits. Secondly, regular testing can help identify any potential issues or malfunctions in the breaker’s operation, allowing for timely maintenance or replacement. Lastly, it verifies that the circuit breaker will operate correctly under fault conditions, maintaining the reliability and efficiency of the power system. Therefore, regular testing is a critical aspect of substation management.

Testing circuit breakers, especially in the context of high voltage (HV) and medium voltage (MV) substations, is a critical aspect of maintaining and operating electrical systems. Here’s why: 

  1. Safety: A “circuit breaker” is a safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit condition. Regular testing ensures that these devices are functioning correctly and can respond promptly when needed. 
  2. Reliability: “High voltage circuit breaker testing” and “medium voltage circuit breaker testing” are essential to ensure the reliability of power distribution. Electrical substations, which often operate at these voltage levels, are critical infrastructure for the distribution of electricity. A malfunctioning circuit breaker can lead to power outages, affecting homes, businesses, and public services.
  3. Maintenance Planning: “Testing circuit breaker in MV and HV substations” can reveal potential issues before they become serious problems. This allows for planned maintenance and repairs rather than emergency interventions, saving time, money, and resources. 
  4. Regulatory Compliance: In many jurisdictions, regular testing of electrical equipment, including circuit breakers, is required by law or industry regulations. Testing helps to ensure compliance with these requirements. 
  5. Longevity of Equipment: Regular testing can extend the life of circuit breakers and associated equipment by identifying issues early and allowing for preventative maintenance.

In conclusion, regular testing of circuit breakers in MV and HV substations is a crucial practice that ensures safety, reliability, regulatory compliance, effective maintenance planning, and longevity of equipment. EuroSMC is focussed in giving the right suport to our customer by providing the most efficient solutions to perform these tests in the safest and fastest way. 


Join thousands of companies around the world using SMC for testing substations and protection relays. SMC has more than 60 representatives and distributors worldwide