Multimeter phase sequence test and precautions
1) Turn the gear to the phase sequence detection gear.
2) The yellow, black and red test leads are inserted into the c, COMb and VΩa sockets in sequence.
3) Match the red, black, and yellow of the test leads to A, B, and C (or L1, L2, and L3) respectively. When the red, black test leads are connected, the indicator light is slightly on, and when the yellow test lead is connected, the indicator light is on, indicating that it is a positive phase sequence; when the indicator light is off, it indicates a reverse phase sequence.
4) The phase sequence file can also measure the phase-to-phase voltage at the same time.
Precautions when using a clamp-on multimeter
1. Before using the digital multimeter, read the instruction manual carefully to familiarize yourself with the function of the power switch and the function of the limit switch, input jack, socket, and various function keys, knobs, and accessories. In addition, you should also understand the limit parameters of the multimeter, the characteristics of overload display, polarity display, low voltage display and other symbol display and alarm, and grasp the changing law of the decimal point position. Before measurement, carefully check whether the test lead is cracked, whether the insulation layer of the lead wire is damaged, and whether the position of the test lead is inserted correctly to ensure the safety of the operator.
2. Before each measurement, check again whether the measurement item and the limit switch are in the correct position, and whether the input jack (or special jack) is selected correctly.
3. The meter will jump when just measuring, and the display value should be stable before reading.
4. Although there is a relatively complete protection circuit inside the digital multimeter, it is still necessary to avoid operational misoperations as much as possible, such as using a current block to measure voltage, using an electric block to measure voltage or current, and using a capacitor block to measure charged Capacitors, etc., so as not to damage the meter.
5. If only the highest digit displays the number "1" and the other digits are blanked, it proves that the meter has been overloaded and a higher limit should be selected.
6. It is forbidden to toggle the limit switch when measuring a voltage above 10OV or a current above 0.5A, so as not to generate an arc and burn the contacts of the transfer switch.
7. The number marked with the danger mark next to the input jack represents the limit value of the input voltage or current of the jack. Once exceeded, it may damage the instrument and even endanger the safety of the operator.
8. The clamp multimeter is not allowed to measure the current of the high-voltage line, and the voltage of the measured line cannot exceed the voltage level specified by the clamp meter (generally no more than 500 volts), in order to prevent insulation breakdown and personal electric shock.
9. The measurement should estimate the size of the measured current and select the appropriate range. It is not possible to use the small range gear to measure the large current. Do not use the resistance gear and current gear to measure the voltage, otherwise, if you are not careful, the meter will be burned.
11. Only one wire can be clamped for each measurement. When measuring, the wire to be tested should be placed in the center of the jaws to improve the accuracy of the measurement. It is best to level the body of the watch with your hands, and try not to let the wire lean against the jaws and the body of the watch.
12. After the measurement, the range switch must be turned to the maximum voltage range position, and then the power switch should be turned off. To ensure safe use next time.
