How to check かどうか there is leakage with a clamp 電流計
導体 of the circuit under test passing through the iron core becomes the primary coil of the current transformer, in which current is induced the secondary coil. As a result, the 電流計 connected to the secondary coil will have an indication to measure the current of the circuit under test. The clamp meter can be changed to different measuring ranges by turning the switch. しかし, it is not allowed to operate with power on when shifting gears. Clamp meters generally have low accuracy, usually level 2.5 to level 5. For ease of use, the meter also has switches of different ranges to provide the functions of measuring current and voltage at different levels.
いつ 使用 a クランプ 電流計 に 検出 電流, be sure to clamp a conductor (wire) being measured. If two (parallel wires) are sandwiched, the current cannot be detected. In addition, when using the center (core) detection of the clamp ammeter, the detection error is small. When checking the power consumption of home appliances, it is more convenient to use a line splitter. Some line splitters can amplify the detection current by 10 times, so currents below 1A can be amplified before detection. When using a DC clamp ammeter to detect DC current (DCA), if the current flows in the opposite direction, a negative number will be displayed. You can use this function to detect whether the car's battery is charged or discharged.
で distribution transformer, disconnect the neutral wire on the outlet side the the AC contactor that controls the low-voltage line, install the removed fuse core on one of the phases, and measure the phase with a clamp ammeter. The current obtained is the leakage current of that phase. Measure the leakage current of the other leakage phases in sequence in the same way. In order to prevent the instrument from being damaged by large current due to phase line grounding on the line (for example, someone uses the wire-to-ground method to steal electricity, etc.), first place the clamp ammeter in the high-current position during detection; if the detection value is very small, then Switch the clamp ammeter to milliamp detection.
the case of low-voltage line power transmission, the clamp-type 電流計 can also be used to detect the low-voltage user connection lines within the suspected range. During detection, the phase line and neutral line of single-phase users should be placed in the jaws of the clamp ammeter at the same time, and the the three phase lines and neutral lines of three-phase power users should also be placed in the the jaws of the クランプ 電流計 at the same time. If there is no leakage fault, the phasor sum of the load current magnetic flux is zero, and the clamp 電流計 徴候 is also zero; if there is leakage current, the clamp 電流計 can detect the leakage current。
The method to check whether there is leakage in the user's internal circuits and equipment is: use a clamp 電流計 to measure the leakage current at the user's power incoming line. At the same time, put the user's electrical equipment and lamps in and out one by one, and detect the leakage current by looking at the clamp ammeter. changes to find leaky equipment and fixtures. If all the equipment and lamps are good, or the equipment with leakage has been removed, but the clamp 電流計 shows that the user still has leakage current, it may be the user's low-voltage line has leakage, and it should be dealt with according to the specific situation. For leakage faults in pre-buried and concealed pipelines, the only solution is to replace or rewire them.
