Circuit breakers play a critical role in protecting power networks, industrial facilities, and essential infrastructure, which means regular testing is necessary. Accurate circuit breaker timing test results are essential to verify correct operation and detect early signs of failure giving breaker testing specialists and electrical testing teams the confidence to keep critical assets performing reliably.
Perform high voltage breaker testing and circuit breaker maintenance safely with Megger's advanced circuit breaker testers. Purpose-built technologies and proven test methods help you verify breaker condition while maintaining safe working practices and protecting personnel and critical equipment.
Breaker failures can lead to extended outages and equipment damage. Megger’s diagnostic tools, combined with reliable circuit breaker testers, help engineers detect mechanical wear, contact degradation, and performance issues early through consistent breaker testing. This ensures reliable protection and reduces the risk of unexpected failure.
Use circuit breaker timing test results and diagnostic data to support condition-based maintenance and identify breakers at risk of failure. Megger's circuit breaker testers provide the insight needed to plan maintenance, optimise capital investment, and make informed asset management decisions.
There are many reasons for high voltage breaker testing. Some of the most important are to ensure they:
The two predominant standards are:
NETA also has acceptance testing (NETA ATS) and maintenance testing (NETA MTS) specifications that cover a broad range of electrical equipment, including circuit breakers. This means that when finding the right breaker testing company for you, it's important to find one that adheres to these standards, such as Megger.
First, make a reference measurement (footprint) of the circuit breaker when it is new and use this to compare future tests. Use the default settings for speed calculation points. Alternatively, if the circuit breaker is older, check to see if several breakers of the same type are available to test. Compare results with other circuit breakers of the same kind. These should be from the same manufacturer and model type, not just the same rated voltage and current. Also, you can make some checks within the test. For most breakers, all three phases should be within 1 to 2 ms of each other, but occasionally a 3 to 5 ms difference may occur for some older breakers. When the breaker has multiple breaks per phase, the difference between contacts in the same phase should be approximately 2 ms or less. On modern circuit breakers, the trip times should be between 20 to 45 ms, with close times taking longer but generally less than 60 ms.
Testing should be done at various stages in the life of a circuit breaker, including:
The manufacturer typically provides a list of the parameters you should check and the range of values you should expect. The list can vary by breaker design, but if none is provided, at a minimum, your company's breaker testing should measure the following:
Contact us to talk about your unique circuit breaker testing needs. One of our experts will reach out to you to offer more information and assistance.
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