How to use and pay attention to the clamp meter when measuring with an electrician
There are two types of clamp ammeters, high voltage and low voltage, which are used to directly measure the current in the line without disconnecting the line. How to use it:
(1) When using a high-voltage clamp meter, pay attention to the voltage level of the clamp ammeter. It is strictly forbidden to use a low-voltage clamp meter to measure the current of a high-voltage circuit. When measuring with a high-voltage clamp meter, it should be operated by two people. Non-duty personnel should also fill in a second work ticket when measuring. They should wear insulating gloves and stand on an insulating pad when measuring. They should not touch other equipment to avoid short circuit or grounding.
(2) When observing the timing of the meter, special attention should be paid to maintaining a safe distance between the head and the live parts. The distance between any part of the human body and the live body shall not be less than the entire length of the clamp meter.
(3) When measuring on a high-voltage circuit, it is prohibited to use wires from the clamp-type ammeter to another meter for measurement. When measuring the current of each phase of a high-voltage cable, the distance between the cable heads should be more than 300mm and the insulation should be good. The measurement can only be carried out when it is considered convenient.
(4) When measuring the current of low-voltage fusible fuses or horizontally arranged low-voltage busbars, each phase fusible fuse or busbar should be protected and isolated with insulating materials before measurement to avoid inter-phase short circuit.
(5) When one phase of the cable is grounded, measurement is strictly prohibited. Prevent the occurrence of ground breakdown explosion due to the low insulation level of the cable head, which may endanger personal safety.
(6) After the measurement of the clamp ammeter is completed, pull the switch to the maximum range to avoid inadvertent overcurrent the next time it is used; and it should be kept in a dry room.
How to use a digital clamp meter:
1. Mechanical zero adjustment must be performed before measurement;
2. Next, you need to choose the appropriate range. Choose the large range first and then the small range. You can also estimate it based on the nameplate value of the electrical appliance;
3. When using the minimum range for measurement, the reading may not be obvious. In this case, it is necessary to wind the wire to be measured a few turns, and the number of turns should be based on the number of turns in the center of the jaw. In this case The reading is: reading = indicated value × range / full deviation × number of turns;
4. When measuring, the wire to be measured should be located in the center of the jaws, and the jaws should be closed tightly, which can effectively reduce errors;
5. When the measurement is completed, switch the installation switch to the maximum range.
