Clamp ammeter common faults and solutions
Clamp ammeter is divided into high and low voltage two kinds, used in the case of not dismantling the line to directly measure the current in the line. Its use is as follows:
(1) the use of high-voltage clamp meter should pay attention to the clamp ammeter voltage level, it is strictly prohibited to use low-voltage clamp meter to measure the current of high-voltage circuit. Measurement with a high-voltage clamp meter, should be operated by two people, non-duty personnel measurement should also fill out the second work ticket, measurement should wear insulated gloves, stand on insulating mats, and shall not touch other equipment to prevent short-circuit or grounding.
(2) Observe the meter time, pay special attention to maintain a safe distance between the head and the charged part, the distance between any part of the human body and the charged body shall not be less than the whole length of the clamp meter.
(3) When measuring on the high-voltage circuit, it is prohibited to use the wire to connect another meter from the clamp-on ammeter to measure. Measurement of high-voltage cable current of each phase, the distance between the cable head line should be more than 300mm, and good insulation, to be considered convenient to measure, before proceeding.
(4) When measuring the current of low-voltage fusible fuse or horizontally arranged low-voltage busbar, each phase of fusible fuse or busbar shall be protected and isolated with insulating material before measurement to avoid short-circuiting between phases.
(5) Measurement is strictly prohibited when one phase of the cable is grounded. To prevent the occurrence of low insulation level of the cable head to ground breakdown explosion and endanger personal safety.
(6) After the clamp ammeter measurement, pull the switch to the maximum range gear, so as to avoid inadvertent overcurrent in the next use; and should be stored in a dry room.
Solutions of clamp-on ammeter
(1) When measuring current or voltage, one or several files have no indication, and other files indicate normal. The reason is that the clamp meter fastening switch screws loose, or its splitter switch on the line was twisted off. This fault is the most common, after the cover will be broken line can be connected.
(2) current file reading is small, voltage file reading is normal. The reason is mostly due to bad contact with the jaws, too much magnetic leakage caused by the jaws should be corrected to make good contact. This kind of failure is sometimes caused by a short circuit between the windings, it is more troublesome, the general metre said to be rewound in accordance with the original data, but also aging treatment.
(3) current and voltage readings are low, this phenomenon often occurs in the magnetic clamp meter. The reason is that the magnet is demagnetised, generally should be magnetised to solve the problem, but also by reducing the resistance value in series with the head branch to adjust.
(4) one of the readings are not allowed, the corresponding resistance should be adjusted.
(4) One of the readings is not allowed, the corresponding resistance should be adjusted. (5) The voltage file indicates normal, and the current file has no indication at all. Apply the multimeter to check the primary switch and secondary winding to see if there is any abnormality.
(6) all no indication. Should check the rectifier diode, meter head, switch, and the clamp meter connected or related wiring is broken.
