Usage of clamp type Ammeter
1. First, correctly select the voltage level of clamp type Ammeter, and check whether its appearance insulation is good, whether there is damage, whether the pointer swings flexibly, and whether the jaw is rusted. Estimate the rated current based on the motor power to select the range of the meter.
2. Read the instruction carefully before using the clamp Ammeter to find out whether it is an AC or AC/DC clamp meter.
3. Since the clamp Ammeter itself has low accuracy, the following method can be used to measure small current: first, wind the wire of the circuit to be measured for several turns, and then put it into the jaw of the clamp for measurement. At this point, the current value indicated by the clamp meter is not the actual value being measured, and the actual current should be the reading of the clamp meter divided by the number of coils wound on the wire.
4. When measuring, the jaws of the clamp type watch should be tightly closed. If there is any noise after closing, the jaws can be opened and reset once. If the noise cannot be eliminated, the joint surfaces on the magnetic circuit should be checked for smoothness. If there is dust, it should be wiped clean.
5. The clamp meter can only measure the current of one phase wire at a time, and the measured wire should be placed in the center of the clamp window. It is not allowed to clamp all multiphase wires into the window for measurement.
6. The voltage of the tested circuit should not exceed the value indicated on the clamp meter, otherwise it may cause grounding accidents or electric shock hazards.
7. Measure the working current of the cage asynchronous motor during operation. According to the current, it is possible to check and judge whether the motor works normally, so as to ensure the safe operation of the motor and extend its service life.
8. During measurement, it can be measured once for each phase or three phases. At this time, the number on the meter should be zero (because the sum of the three phase current is zero). When there are two phase lines in the jaw, the value displayed on the meter is the current value of the third phase. By measuring the current of each phase, it can be judged whether the motor has overload (the measured current exceeds the rated current value), Whether there is a problem with the power supply voltage inside the motor or (the device that converts other forms of energy into electrical energy is called the power supply), that is, whether the three-phase current imbalance exceeds the limit of 10%.
9. Before measuring with a clamp meter, the magnitude of the measured current should be estimated before deciding which range to use. If it is impossible to estimate, the maximum range range can be used first and then reduced appropriately to obtain accurate readings. Small current ranges cannot be used to measure large currents. To prevent damage to the instrument.
