10 Safety Points to Pay Attention to When Using Clamp Ammeter
1. In order to prevent insulation breakdown and personal electric shock, the voltage of the line under test must not exceed the rated voltage of the clamp ammeter, let alone the current of the high-voltage line.
2. Before measuring, check whether the pointer of the meter is at zero. If it is not at zero, it should be adjusted to zero. At the same time, the measured current should be roughly estimated and an appropriate range should be selected. If the measured current cannot be estimated, first place the clamp ammeter in the highest gear, and gradually lower the switch until the pointer is in the middle of the scale.
3. Attention should be paid to the voltage level of the clamp ammeter, and the low voltage meter should not be used to measure the current of the high voltage circuit to avoid accidents.
4. When measuring, the measured wire should be placed in the center of the jaw. The two surfaces of the jaws should be well connected. If vibration or collision sound is found, the instrument wrench should be moved a few times, or opened and closed again. There is dirt on the jaws, which can be cleaned with gasoline.
5. After measuring a large current, if you measure a small current immediately, you should open and close the jaws several times to eliminate the residual magnetism in the iron core.
6. Do not switch the range during the measurement, so as not to cause the secondary circuit to open instantly, induce high voltage and break down the insulation. When the range must be changed, the jaws should be opened first.
7. When measuring in a place where it is difficult to read the current reading, you can first lock the pointer with the brake, and then read the value at a convenient place for reading.
8. If the wire to be tested is a bare wire, the adjacent phases must be isolated with insulating plates in advance to avoid phase-to-phase short circuit when the jaws are opened.
9. When measuring a current less than 5A, in order to obtain an accurate reading, the wire can be wound several times and put into the jaw for measurement, but the actual current value is the reading divided by the number of wires put into the jaw.
10. When measuring, if there are other current-carrying wires nearby, the measured value will be affected by the current-carrying conductor and cause errors. At this time, the jaw should be placed on the side away from other conductors.
