Product Introduction:
The A-300 three-phase multifunctional volt-ampere phase meter can not only measure AC voltage, but also measure AC current without disconnecting the circuit under test. It can also measure the phase between two voltages, between two currents, and between voltage and current.
The A-300 three-phase multifunctional volt-ampere phase meter is a high-precision, low-cost, portable, handheld, dual-channel input measuring instrument specially designed for on-site measurement of voltage, current, and phase. With this meter, you can conveniently measure the phase between U-U, I-I, and U-I on site, distinguish inductive and capacitive circuits and the phase sequence of three-phase voltage, detect the connection group of transformers, test secondary circuits and bus differential protection systems, read out the phase relationship between CTs of each group in differential protection, check whether the wiring of the electric energy meter is correct, etc. It uses a clamp-type current transformer for input of the measured current, so there is no need to disconnect the circuit under test during measurement. When measuring the phase between U1-U2, the two input circuits are completely insulated and isolated, thus completely avoiding possible short circuits of the circuit under test caused by incorrect wiring, which could burn out the measuring instrument. The display uses a high-contrast LCD screen with oversized characters for optimal visual effect.
Usage Instructions:
1. Measuring AC Voltage
Turn the rotary switch to the 500V range corresponding to parameter U1, and input the voltage to be measured from the U1 jack to start measurement. If the measured value is less than 200V, you can directly rotate the switch to the 200V range corresponding to U1 for measurement to improve accuracy. Both channels have identical voltage testing characteristics, so you can also set the switch to the range corresponding to parameter U2 and input the voltage from the U2 jack for measurement.
2. Measuring AC Current
Turn the rotary switch to the 10A range corresponding to parameter I1, insert the plug of the secondary lead of the clamp-type current transformer labeled 1# into the I1 jack, and clamp the jaws onto the circuit under test to start measurement. Similarly, if the measured value is less than 2A, you can directly rotate the switch to the 2A range corresponding to I1 for measurement to improve accuracy. When measuring current, you can also set the rotary switch to the range corresponding to parameter I2, connect the measuring clamp labeled 2# to the I2 jack, and clamp its jaws onto the circuit under test for measurement.
3. Measuring the Phase Angle Between Two Voltages
To measure the phase angle of U2 lagging behind U1, set the switch to parameter U1U2. During measurement, you can rotate the switch clockwise to the ranges of parameter U1 at any time to measure the U1 input voltage, or rotate it counterclockwise to the ranges of parameter U2 to measure the U2 input voltage.
4. Measuring the Phase Angle Between Two Currents
To measure the phase angle of I2 lagging behind I1, set the switch to parameter I1I2. Similarly, during measurement, you can rotate the switch clockwise to the ranges of parameter I1 to measure the I1 input current, or rotate it counterclockwise to the ranges of parameter I2 to measure the I2 input current.
5. Measuring the Phase Angle Between Voltage and Current
Input the voltage from U1, use the measuring clamp 2# to input the current from I2, and rotate the switch to the parameter U1I2 position to measure the angle by which the current lags the voltage. During the test, you can rotate the switch clockwise to the ranges of parameter I2 to measure the current, or counterclockwise to the ranges of parameter U1 to measure the voltage.
Alternatively, you can input the voltage from U2, use the measuring clamp 1# to input the current from I1, and rotate the switch to the parameter I1U2 position to measure the angle by which the voltage lags the current. Similarly, during measurement, you can rotate the switch at any time to measure the value of I1 or U2.
6. Phase Sequence Discrimination for Three-Phase Three-Wire Distribution Systems
Set the rotary switch to the U1U2 position. Connect phase A of the three-phase three-wire system to the U1 jack, phase B simultaneously to the ± jack corresponding to U1 and the ± jack corresponding to U2, and phase C to the U2 jack. If the measured phase value is around 300°, the system under test has a positive phase sequence; if the measured phase is around 60°, the system under test has a negative phase sequence.
Alternatively, connect phase A to the U1 jack, phase B simultaneously to the ± jack corresponding to U1 and the U2 jack, and phase C to the ± jack corresponding to U2. In this case, if the measured phase value is 120°, it is a positive phase sequence; if the measured phase value is 240°, it is a negative phase sequence.
7. Phase Sequence Discrimination for Three-Phase Four-Wire Systems
Set the rotary switch to the U1U2 position. Connect phase A to the U1 jack, phase B to the U2 jack, and the neutral line simultaneously to the ± jacks of both input circuits. If the phase display is around 120°, it is a positive phase sequence; if the phase display is around 240°, it is a negative phase sequence.
8. Inductive and Capacitive Load Discrimination
Set the rotary switch to the U1I2 position. Connect the load voltage to the U1 input terminal, and the load current through the measuring clamp to the I2 jack. If the phase display is in the range of 0° to 90°, the load under test is inductive; if the phase display is in the range of 270° to 360°, the load under test is capacitive.
