The digital phase sequence meter is a high-precision, low-cost, handheld, dual-channel input measuring instrument designed for field measurement of voltage, current and phase. With this meter, you can easily measure the phase between UU, II and UI on site, distinguish the phase sequence of inductive, capacitive circuits and three-phase voltage, detect the wiring group of the transformer, and test the secondary circuit and bus differential protection system. , Read the phase relationship between the CTs of each group of differential protection, and check whether the wiring of the watt-hour meter is correct or not.

1. Use clamp-type current transformer conversion method to input the measured current, so there is no need to disconnect the measured line during measurement.

2. When measuring the phase between U1-U2, the two input circuits are completely insulated and isolated, so it completely avoids the possible short circuit of the line under test caused by miswiring, which may burn the measuring instrument.

3. The display adopts a high-contrast liquid crystal display, the characters are up to 25mm, and the screen angle can be freely converted about 70° to obtain the best visual effect.

4. The instrument shell is made of engineering insulating materials, and is equipped with a rubber anti-vibration protective cover, which is safe and reliable.

1. Reference working conditions

1) Ambient temperature: (23±5)℃

2) Environmental humidity: (45～75)% RH

3) The measured signal waveform: sine wave, β=0.02

4) Frequency of tested signal: (50±0.2) Hz

5) The position of the tested current-carrying wire in the jaws: any

6) Range of measured signal amplitude when measuring phase: 100～220V, 0.5A～1.5A

7) External reference frequency electromagnetic field interference: should be avoided

2. Basic error limit

1) AC voltage (see Table 1)

Table 1: AC voltage measurement error

Input impedance: each limit is 2MΩ

2）AC current (see Table 2)

Table 2: AC current measurement error

3） Phase

U-U、U-I、I-I（See Table 3）

Table 3: Power frequency phase measurement error

Voltage input loop impedance when measuring U1-U2 phase: 40kΩ

1. Rated working conditions

1) Ambient temperature: (0～40)℃

2) Environmental humidity: (20～80)% RH

3) The measured signal waveform: sine wave, β=0.05

4) Frequency of the measured signal: (50±0.5) Hz

5) The position of the tested current-carrying wire in the jaws: any

6) Range of measured signal amplitude when measuring phase

When measuring U1-U2 phase: 30V～500V

When measuring I1-I2 phase: 10mA～10.00A

When measuring U1-I2 or I1-U2 phase: 10V～500V, 10mA～10.00A

7) External reference frequency electromagnetic field interference: should be avoided

2. Rated working error limit

Under the above-mentioned rated working conditions, each measured rated working error limit does not exceed twice the corresponding basic error limit.

1. Display digits: three and a half digits

2. Sampling rate: 3 times/sec

3. Power supply: single 9V laminated battery, power supply current is less than 5mA

4. Dimensions

Case size: 192mm×95mm×55mm

Clamp shell size: 140mm×42mm×20mm

Jaw size: Φ7mm×9mm

5. Weight

Body: 280g

Measuring pliers: 2×200g

6. Storage conditions

Temperature: -10℃～50℃

Press the ON-OFF button and rotate the function range switch to correctly select the test parameters and limits.

1. Measure AC voltage

Turn the function range switch to the 500V limit corresponding to parameter U1, and then input the measured voltage from the U1 jack to start measurement. If the measured value is less than 200V, you can directly rotate the switch to the 200V measurement limit corresponding to U1 to improve the measurement accuracy.

The two channels have exactly the same voltage test characteristics, so you can also set the switch to the corresponding limit of parameter U2, and input the measured voltage from the U2 jack for measurement.

2. Measure AC current

Set the rotary switch to the 10A measurement limit corresponding to the parameter I1, insert the lead-out plug of the secondary side of the clamp-type current transformer labeled I1 into the I1 jack, and the clamp can be clamped on the line to be measured for measurement. Similarly, if the measured value is less than 2A, you can directly rotate the switch to the 2A measurement limit corresponding to I1 to improve the measurement accuracy.

When measuring current, you can also set the rotary switch to the corresponding limit of parameter I2, and connect the measuring clamp labeled I2 to the I2 jack, and the clamp jaw is clamped on the line to be measured for measurement.

3. Measure the phase angle between the two voltages

When measuring the phase angle of U2 lagging U1, turn the switch to parameter U1U2. During the measurement process, you can turn the switch clockwise to the limits of parameter U1 and measure the input voltage of U1 at any time, or rotate the switch counterclockwise to the limits of parameter U2 to measure the input voltage of U2.

Note: The symbols U1 and U2 next to the voltage input jack and the red “" symbol of the clamp-on current transformer are the ends of the phase with the same name when measuring the phase.

4. Measure the phase angle between the two currents

When measuring the phase angle of I2 lagging I1, set the switch to parameter I1I2. In the same measurement process, you can turn the switch clockwise to the maximum limit of parameter I1 at any time to measure the input current of I1, or turn the switch counterclockwise to the limit of parameter I2 to measure the input current of I2.

5. Measure the phase angle between voltage and current

Input the voltage from U1, and use the I2 measuring clamp to input the current from I2, turn the switch to the position of parameter U1I2, and measure the angle at which the current lags the voltage. During the test, you can turn the switch clockwise to measure current at each limit of parameter I2 at any time, or turn the switch counterclockwise to measure voltage at each limit of parameter U1 at any time.

You can also input the voltage from U2, use the I1 measuring clamp to input the current from I1, turn the switch to the position of parameter I1U2, and measure the angle at which the voltage lags the current. Similarly, the switch can be rotated at any time during the measurement process to measure the value of I1 or U2.

6. Phase sequence discrimination of three-phase three-wire power distribution system

Set the rotary switch to the U1U2 position. Connect the A phase of the three-phase three-wire system to the U1 jack, and the B to the ± jack corresponding to U1 and the ± jack corresponding to U2 at the same time, and the C phase to the U2 jack. If the measured phase value is about 300° at this time, the system under test has a positive phase sequence; if the measured phase value is around 60°, the system under test has a negative phase sequence.

For another measurement method, connect phase A to the U1 jack, connect phase B to the ± jack corresponding to U1 and the U2 jack at the same time, and connect phase C to the ± jack corresponding to U2. At this time, 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 of three-phase four-wire system

Set the rotary switch to the U1U2 position. Connect phase A to the U1 jack and phase B to the U2 jack, and connect the neutral line to the ± jacks of the two input circuits at the same time. If the phase display is about 120°, it is a positive phase sequence; if the phase display is about 240°, it is a negative phase sequence.

8. Judgment of inductive and capacitive load

Set the rotary switch to the U1I2 position. Connect the load voltage to the U1 input terminal, and connect the load current to the I2 jack through the measuring clamp. If the phase is displayed in the range of 0°～90°, the measured load is inductive; if the phase is displayed in the range of 270°～360°, the measured load is capacitive.

If you need to change the angle of the display, you can press the lock button on the top of the display with your fingers and turn the display to the most suitable angle for observation.