Circuit Breaker Testing

Circuit Breaker TestingIndustrial Tests, Inc. provides comprehensive Circuit Breaker Testing services as part of our Electrical Testing and Maintenance services. We perform Circuit Breaker Testing for industrial plants, large commercial facilities and municipal power stations. We are available 24 hours a day, seven days a week and are maintenance manager’s first choice for electrical testing, maintenance and repair.

Preventative Maintenance, Inspection, and Testing

Preventative maintenance depend operating conditions for circuit breakers.  Primary inspections of CB (circuit breakers) will look at particulate matter that’s contaminating the inner workings of the CB.  Accumulation of particulates can generally be disposed of by flipping the lathc on the breaker “Off” and “On” switch to clear away the accumulated dust.

General Procedures for Routine Field Testing

Routine field testing does not need to involve complicated equipment in order to verify that a CB is in working condition.  Some guidelines and recommendations for these tests include routine maintenance and verifying that that circuit breaker performance is in line with manufacture’s calibration curves.  It is important that these tests are done under controlled conditions at am ambient temperature so there are no distortions in the data.  Some of the tests are listed below.

Insulation Resistance Test

For individual breaker resistance testing, load and line conductors should be preferably disconnected. If not disconnected the test measurements will also include the characteristics of the attached circuit.  Resistance testing is crucial for verifying that the insulating material which makes up the molded cases breakers are performing correctly.  In order to test for insulation resistance, an instrument known as a “megger” is used.  A megger instrument applies a known DC voltage to a given wire for a given period of time in order to test the resistance within the insulation on that particular wire or winding.  It is important that voltage is applied because resistance tested with an ohm meter may vary when there are no potential differences present.  It should also be noted that if you apply a voltage that is too high for that insulation to withstand, then you could potentially damage the insulation.  Meggers are rated and have specific settings that range from 300, 600, 1000, and 3000 Volt settings.   The trained technicians and engineers at ITI specialize in megger usage and insulation resistance testing.

Connection Tests

Connection testing is vital to ensure that a proper electrical join is present and to identify signs of overheating marked by discoloration.  It is important that electrical connections are properly installed to the CB to prevent and reduce overheating.  ITI specializes in connection testing and are knowledgeable enough to know that aluminum connectors are plated and should not be abrasively cleaned.  ITI will repair and replace damaged aluminum connectors (lugs) to prevent further damage.

Contact Resistance Test

Normal wear and tear of contacts within the CB emerges after extended usage.  A routine and simple way to determine signs of deterioration within the CB is to measure the resistance across each pole of the breaker. ITI induces a current across a CB and uses a voltmeter to determine the voltage across the breaker.  By knowing the current induced and the measured voltage, ITI is able to determine the contact resistance based on ohms law.  Indications of abnormal conditions within the CB such as erosion and contamination of contacts are evident if there are excessive millivolt drops across the breaker.  The contact resistance test is vital in determining whether or not a CB is still fit for operation.

Overload Tripping Test

Overload tripping components of CBs can be tested by inputting 300% of the breaker rating into each pole of the circuit breaker to determine that it will open automatically.  The reason for this test is to ensure that the CB will function.  Refer to NETA standards for trip times that are acceptable for the overload tripping test.  When trying to determine tripping characteristics other than whether or not the CB is functional, it is wise to refer to manufacturer’s trip curves and instruction manuals.

Instantaneous Magnetic Tripping

When it comes to routine tests, it is more pertinent to determine that the magnetic feature is operational and will trip the CB rather than determining the exact value at which the instantaneous magnetic feature operates.

For any of the testing procedures listed above, or for more information, please feel free to contact ITI.  We are more than happy to assist.

Industrial Tests, Inc. Providing Circuit Breaker Testing To California And Nationwide

With offices in outside Sacramento and Fresno, California, Industrial Tests, Inc. provides Circuit Breaker Testing services to clients throughout California including San Francisco, Los Angeles and San Diego as well as Arizona, Nevada, Oregon, Washington, Texas and nationwide. We serve industrial, commercial and municipal clients in various industries including power stations, power plants, wind and solar, petro-chemicals, manufacturing, hotels, hospitals, municipalities, defense contractors, data centers and many other applications that rely on high power electric equipment. Whatever your Circuit Breaker Testing needs may be, contact us and we will make sure that your equipment is treated with the care and safety requirements that it deserves. See our full line of electrical testing.

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