Common Faults and Treatment Methods of Clamp Ammeter
1. When measuring current or voltage, there is no indication for one or several gears, and the indications for other gears are normal. The reason is that the fastening switch screw of the clamp meter is loose, or the connection wire on the branch switch is twisted. This kind of failure is the most common, just connect the broken wire after opening the cover.
2. The indication of the voltage gear is normal, but there is no indication of all the current gears. Use a multimeter to check the primary wire switch and secondary winding to see if there is any abnormality.
3. There is no indication at all. Check the rectifier diode, meter head, switch, and the connection with the clamp meter or related wiring for breaks.
4. The readings of the current and voltage files are all low. This phenomenon often occurs on the internal magnetic clamp meter. The reason is that the magnet is demagnetized. Generally, it should be magnetized to solve it. It can also be solved by reducing the resistance value connected in series with the branch circuit of the meter head. Make adjustments.
5. If the reading of one of the gears is inaccurate, the corresponding resistance should be adjusted.
6. The reading of the current gear is too small, and the reading of the voltage gear is normal. Most of the reasons are due to poor contact of the jaws and too much magnetic flux leakage. The jaws should be corrected to make them in good contact. This kind of fault is sometimes caused by short circuit between windings, and it is more troublesome at this time. Generally speaking, it is necessary to rewind according to the original data, and aging treatment is also required.
A Simple Method of Measuring AC Current with a Clamp Ammeter
1. The structure of clamp ammeter
The clamp ammeter is actually an AC current transformer, which is equivalent to a transformer with only one primary turn and many secondary turns, and the secondary load is the previous AC ammeter.
2. Clamp ammeter to measure AC current
When the clamp ammeter clamps a phase line, it is equivalent to having a primary winding. At this time, the working current induces a magnetic flux in the iron core circuit of the clamp ammeter, and the magnetic flux passes through the secondary winding to induce a secondary voltage and form a current in the secondary load.
The size of this secondary current is directly proportional to the primary current, so the value indicated by the gauge head can indirectly reflect the size of the primary working circuit current.
