Many utilities conduct periodic tests of their protective relay systems. These tests help ensure that the power system is protected against faults and that protection schemes operate properly. These tests check a variety of factors, including: -Relay settings. These should align with the latest coordination and arc-flash study and engineered setting files.
Protective Relay Tester Features
Protective relays and relay systems are the industry’s most powerful defense against long outages and extensive equipment damage. Testing of protective devices is essential for safe operation of electrical transmission and distribution. The Megger MPRT 8430 is designed to perform routine testing of protection systems used by electric utilities, power plants and heavy industrials. It’s also used by relay manufacturers, panel manufactures and testing service companies.
AVTS Basic software, which comes with the MTS-5100 Protective relay tester System and earlier MTS-5000, includes built-in, preset tests for most popular relays. It also offers several productivity modes that allow users to set up and run tests quickly and easily.
Before beginning a test, inspect the relay and case for physical damage and deterioration. Check the target reset functionality, disk clearance, contact clearance and spring bias. Inspect the relay for foreign material in disk slots and a tight cover gasket seal. Verify that all digital inputs and output contacts are operational, and that control and alarm systems are free of alarms.
Safety
Protective relays are used to ensure that electrical systems operate as designed. They can prevent long outages and extensive equipment damage. If you have protective relays on your system, it is vital to test them hot to make sure they are working as designed. Relay testing requires a lot of knowledge and skills. If you are new to this type of testing, it is best to work with a specialist who knows what to look for.
Clean and inspect the relay case and relay front panel for foreign objects, such as metal bits. Clean the relay contacts using a brush or a magnetic contact cleaner. Check that the relay is insulated properly and that there are no abrasions in the moving contact surfaces. Check that the relay is in proper operating position and that it has a valid settings file and coordination study.
Design
As demand for electricity rises, protection relays are the industry’s most powerful defense against long and costly outages. But only correctly operating relays can protect primary equipment and contribute to a stable power grid. That’s why it’s crucial to test and maintain protection relays throughout their entire lifecycle.
Testing is typically divided into acceptance, commissioning and maintenance testing. Acceptance tests check that a relay’s settings align with the latest arc-flash study or engineered setting files. Commissioning tests verify that the relay is able to operate under various fault conditions and shifts.
This video shows you how to set up the MTS-5000 or MTS-5100 test system to automatically generate non-sinusoidal waveforms during Manual Test for a distance relay or other type of inverse time relay. It also demonstrates how you can use the system to display calculated values like impedance, power or symmetrical components on the main test screen and in your reports. This feature can make it much easier to perform pickup tests on relays that respond to rate of change such as a resistance-temperature-detector or frequency relay.
Applications
Test your protection relays to make sure they will work properly when you need them. This prevents more expensive problems down the road and allows you to use your relays as intended.
Some of the more common tests include seal-in operation and testing to a target. You can also test all of the microprocessor analog inputs to verify registration and SCADA meter functions. You can even perform no-go tests to prove that the relays will not operate outside of their protective zones.
Manta’s MTS-5×00 Series of Protective Relay Testers can generate the current required for many tests. They also have convertible voltage channels to test electromechanical relays that require varying amounts of DC current. Moreover, you can control two MTS-5×00 test-sets from one controller. Test reports are saved in html or xml format that can be opened by any device. They can also be imported into RapidReporter software that organizes them by relay and test procedure.
Conclusion
Protective relay tester is a device to test protective devices used in power generation facilities, industrial installations and heavy electrical equipment. It is a versatile tool that performs the most complex tests on medium voltage electromechanical protective relays as well as microprocessor-based relays with phase shifting capabilities.
