It is important that in any test program the proper equipment is used. The Equipment should be calibrated, in good condition, and used by qualified operators. Any test equipment used for calibration shall have twice the accuracy of the equipment to be tested. Care should be taken to use a quality or regulated power source for the equipment as voltage, frequency, and waveform variation can produce invalid results. All equipment should be operated in accordance with its instruction manual.
The testing of electrical power system equipment involves checking the insulation adequacy, electrical properties, protection and control, operation, and other items as they relate to the overall system. Some of these checks are accomplished using de-energized component tests, instrumentation and relay operation and calibration tests, energized functional testing of control circuits, megger testing of power circuits, phase-out testing of power circuits, and service testing.
The purpose of electrical testing on systems and their components is two-fold. The first is to check the installation of the equipment and perform component and systems tests to ensure that, when energized, the system will function properly. The second is to develop a set of baseline test results for comparison in future testing to identify equipment deterioration. The system should be initially checked for damage, deterioration, and component failures using specific component checks, inspections, and tests defined by the equipment manufacturer. Then the interconnection of the system components should be checked, using de-energized and energized methods, to verify the proper interconnection and operation of the components, including on/off control, system process interlocks, and protective relaying functions. Once the above tests are complete, the system can be energized and operational tests and measurements should be performed. All steps and results of the testing should be carefully documented for review and for use in the future for comparison with the results of future tests. Many of the same component tests initially run will be performed at regular intervals as part of a maintenance program. The new results will be compared to the initial results, where variations may be indicative of problems like deterioration of insulation or dirty equipment. The steps involved are to review the system and equipment, develop a general system and specific equipment test plan, provide inspection and checks, perform component testing, verify and check the continuity of wiring, check control functions, calibrate instruments and relays, energize portions of the circuits and check for proper operation in a specific order, and, once complete, perform specific checks and control tests on the complete system during the initial period of operation.