Clamp Meter User Guide How to Choose and Buy a Clamp Meter
1. Read the instruction manual carefully before use to find out whether it is AC or AC/DC.
2. The voltage of the circuit under test cannot exceed the value marked on the clamp meter, otherwise it may easily cause a grounding accident or cause an electric shock hazard.
3. The current of one phase conductor can only be measured at a time. The conductor to be measured should be placed in the center of the clamp window. Multi-phase conductors cannot be clamped into the window for measurement.
4. Before measuring with a clamp meter, you should first estimate the size of the current being measured, and then decide which range to use. If it is impossible to estimate, you can first use the maximum range and then change it to a smaller range to get an accurate reading. You cannot use the small current range to measure large currents. to prevent damage to the instrument.
5. The jaws should be closed tightly during measurement. If there is noise after closing, open the jaws and re-open them once. If the noise still cannot be eliminated, check whether the joint surfaces on the magnetic circuit are smooth and clean, and wipe them clean if there is dust.
6. Since the accuracy of the clamp ammeter itself is low, when measuring small currents, the following method can be used: first wind the wire of the circuit under test several times, and then put it into the jaws of the clamp meter for measurement. At this time, the current value indicated by the clamp meter is not the actual value being measured. The actual current should be the reading of the clamp meter divided by the number of turns of the wire.
7. Do not operate with electricity during maintenance to prevent electric shock.
How to use high and low voltage clamp meters
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 the second work ticket when measuring. They should wear insulating gloves and stand on the insulating pad when measuring. They should not touch other equipment to prevent short circuit or grounding.
2. When observing the timing of the meter, special attention should be paid to keeping 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 deemed 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 short circuit between phases.
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 stored in a dry room.
