If you’re a qualified test technician, then you should know the kind of test equipment to apply to any meter testing or transformer testing task. In most cases, electrical testing entails the application of a current or voltage to a circuit and the comparison of the test measure to the expected results. These test equipment are designed for specific applications. They’re used to verify the math behind the circuits that they measure.
This post reviews everyday test devices used in electrical meter and current transformer testing.
The megohmmeter, also known as a ‘megger,’ is a unique ohmmeter that determines the insulator’s electrical resistance. These equipment generate high voltages through internal circuits or a generator. Megohmmeters determine the insulation capacity of electrical apparatus such as transformers.
Low Resistance Ohmmeter
Low resistance ohmmeters are meters that make resistance measurements of high precision. Typical measurements made are below 1 ohm. These ohmmeters generate a low voltage DC from batteries with an output of at least 100 Amperes. This equipment measures the resistance of different apparatus. These may include fuses, transformers, bus-ways, and circuit breakers.
Transformer Turns Ratio Test Kit (TTR)
The TTR set applies a voltage to the high voltage coil of a transformer to measure the resulting voltage generated by the low voltage coil. The voltage measured by this transformer testing device shows the turns ratio. This tool also measures the percent ratio error, phase angle deviation between windings, and the excitation current.
The Power Factor Test Kit
These kits allow a technician to make AC diagnostic tests for the apparatus of high voltage such as transformers, cables, and bushings. Tested voltages are often below 12 kV. The test equipment measures the current and voltage of the device, getting tested by using reference impedance.
Tests made by this kit measure the dissipation factor and capacitance of a specific specimen. The measured values often change when unwanted conditions such as conductive contaminants occur within the system.
The multi-meter is a device that can measure different parameters on electric meters and circuits. The measured parameters include frequency, resistance, current, and voltage. These hand-held devices are often used to detect electrical flaws in a wide range of electronic and industrial tools, which include power supplies, meters, electronic equipment, and wiring systems.
Winding Resistance Test Kit
These motor and transformer testing sets are crucial in diagnosing possible motor winding and transformer damage. Damaged tap changers’ contacts, loose connections, and shorted turns often change the transformer’s winding resistance. This kit measures the changes by passing a DC in the winding getting tested, and then it measures the voltage drop found across the terminal.
The Wattmeter is a piece of test equipment used to determine the supply rate of electrical energy or power of any circuit. Its unit of measure of electric power is in watts. A thousand watts make up a kilowatt, which is a standard measure of electrical energy consumption.
The Current Transformer Test Kit
A CT test set is a multi-function equipment built to perform insulation, phase deviation, polarity, winding resistance, ratio, demagnetization, and saturation tests on current transformers. Top-notch CT testing devices can connect to multi-ratio current transformers and carry out checks on all taps at the switch of a button and without lead changes.
There are various electrical testing equipment in the market. To get the right test equipment for your meter or transformer testing, you need to know what you want to measure and the perfect tool for the job. The highlighted testing equipment are some of the primary testing devices.
But there are many other meters and transformer testing pieces of equipment for different testing functions. These devices include the hi-potential test set, high current test kit, secondary test set, relay test set, magnetron atmospheric condition test kit, ground resistance test kit, infra-red cameras, vibration testers, load banks, and ultrasonic testers. Pick the right tool for the right job to get proper electrical system diagnostics!