4 Key Points for Clamp Meter Selection
Key Points for Clamp Meter Selection
The clamp ammeter is called clamp meter for short. Its working part is mainly composed of an electromagnetic ammeter and a feed-through current transformer. The core of the core-through current transformer is made into a movable opening and is shaped like a clamp, so it is called a clamp ammeter. It is a portable instrument that can directly measure the AC current of the circuit without disconnecting the circuit. It is very convenient to use in electrical maintenance and widely used.
Key points for clamp meter selection:
1: detection object
Choose the model according to different detection objects, AC current, DC current, or leakage current;
2: Detectable conductor specifications
According to the testing site, there are different specifications from 21mm diameter to 53mm diameter.
3: Is true value detection necessary?
The clamp ammeter using the average value mode cannot correctly detect the non-sinusoidal circuit such as the motor and the circuit of the transformer. The clamp ammeter of the true effective value mode should be used to detect this circuit.
4: Other functions
Not only can detect the current, but also a model that integrates the detection function and record output
How to use the clamp meter and precautions
(1) When using a high-voltage clamp meter, attention should be paid to the voltage level of the clamp ammeter, and it is strictly forbidden to use a low-voltage clamp meter to measure the current of the 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 when measuring, stand on insulating mats, and do not touch other equipment to prevent short circuit or grounding.
(2) When observing the timing of the watch, special attention should be paid to maintaining a safe distance between the head and the live part. The distance between any part of the human body and the live body should not be less than the entire length of the clamp meter.
(3) When measuring on a high-voltage circuit, it is forbidden to use wires to connect the clamp ammeter to another meter for measurement. When measuring the current of each phase of the high-voltage cable, the distance between the cable ends should be more than 300mm, and the insulation should be good, and 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, the fusible fuses or busbars of each phase should be protected and isolated with insulating materials before measurement to avoid short-circuit between phases.
(5) It is strictly forbidden to measure when one phase of the cable is grounded. Prevent personal safety from being punctured and exploded due to the low insulation level of the cable head.
(6) After the measurement of the clamp ammeter, pull the switch to the limit position to avoid accidental overcurrent during the next use; and it should be stored in a dry room.
