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Manoj Sahu
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I was wondering about contact resistance measurment test. Why do we take such test?
jim hardy said:Back about 1973 or '74 high resistance in a contact caused a relay to de-energize and that tripped a nuke plant and that triggered a blackout from Palm Beach to Miami.
Manoj Sahu said:I performed this test on Siemens 33kV GIS 8DB 10 panel. The test results were around 210micro ohm whereas the ideal values were 173micro ohm. I asked my Seniors , how come they calculated the ideal value of 173 micro ohm. They told me that it depends on number of contacts and can be easily calculated by a formula. Though they didn't tell me the formula.What may be the formula? @anorlunda @Asymptotic
How many contacts were involved in this measurement?Manoj Sahu said:I performed this test on Siemens 33kV GIS 8DB 10 panel. The test results were around 210micro ohm whereas the ideal values were 173micro ohm. I asked my Seniors , how come they calculated the ideal value of 173 micro ohm. They told me that it depends on number of contacts and can be easily calculated by a formula. Though they didn't tell me the formula.What may be the formula? @anorlunda @Asymptotic
I don't exactly remember. Suppose, it is 13. How will we calculate?Asymptotic said:How many contacts were involved in this measurement?
I had to google the name of that plant, but I sure remember that blackout. Even though i wasn't there.anorlunda said:Does the name Sir Adam Beck #2 ring a bell?
Contact resistance measurement is important because it helps ensure the integrity and safety of electrical systems. It allows us to detect any potential faults or failures in the contacts of electrical components, which can prevent malfunction or even fires.
Contact resistance can significantly impact the performance of electrical systems. High contact resistance can lead to voltage drop, heat generation, and even damage to the electrical components. It can also cause intermittent connectivity issues, which can be difficult to diagnose and fix.
There are several factors that can affect the accuracy of contact resistance measurement, including the type and condition of the contacts, presence of contaminants or corrosion, temperature, and the quality of the measuring equipment. It is essential to carefully consider and control these factors to obtain accurate results.
Contact resistance measurement is typically performed using specialized equipment called a micro-ohmmeter. The test involves passing a small current through the contacts and measuring the voltage drop to calculate the resistance. The results are usually compared to a predetermined threshold or standard to determine if the contacts are within the acceptable range.
The frequency of contact resistance measurement can vary depending on the specific system and its usage. In general, it is recommended to perform this test during routine maintenance and whenever there are any suspected issues with the electrical system. It is also crucial to perform contact resistance measurement after any repairs or modifications to the system to ensure its proper functioning.