Is a clamp ammeter required to install the motor?
The clamp ammeter is used to measure the actual current of the one-phase line, because the clamp ammeter is equivalent to a CT with an open primary winding, and the current detected at the first time will be displayed in the second reflection, which has nothing to do with the connection of the three-phase motor.
The first step is to measure the phase alone. You can directly measure the phase voltage on the secondary side of the voltage transformer (the method is the same as above), or you can directly measure the phase voltage (the input terminal of the clamp meter). However, it is necessary to insert the probe and select the appropriate measurement range. Its "bayonet" can only be a special clamp meter for measuring AC current. Make the pointer stay on the right side, use the same method as the ordinary multimeter, and gradually change from high to low when the voltage level is unknown;
The second step is to use the probe to measure the voltage in parallel. The clamp meter cannot directly "clamp" the voltage with its attached multimeter, and adjust the switch to an appropriate range.
1. Use of digital clamp meter
1. Mechanical zero adjustment is required before measurement.
2. Select the appropriate range, first select the large range, then select the small range or look at the nameplate value estimation.
3. When using the minimum measuring range to measure, when the reading is not obvious, the measured wire can be wound several times, and the number of turns should be based on the number of turns in the center of the jaw, then the reading = indicated value × range / full deviation × number of turns.
4. After measuring, put the transfer switch to the maximum range.
5
.When measuring, the wire to be tested should be in the center of the jaws, and the jaws should be tightly closed to reduce errors.
2. Precautions for digital clamp watches
1. The voltage of the line under test should be lower than the rated voltage of the clamp meter.
2. When measuring the current of high-voltage lines, wear insulating gloves, wear insulating shoes, and stand on insulating mats.
3. The jaws should be closed tightly, and the range cannot be changed by electricity.
Measuring the current of the single winding of the motor with a clamp ammeter is the phase current, but it will bring trouble to the actual measurement, or connect all three pairs of winding wires externally. The current on the power line is always the line current; calculating the power of a motor is difficult and impractical. Power factor is a wild card unless you hook up a power factor meter, but you should know that power factor will vary with load.
The above content is relatively simple. If you want to learn more, you can watch a set of plc video tutorials. I hope it can help you. Source of this article: www.jcpeixun.com.
