How to use a clamp ammeter to determine whether there is a leak
The measured circuit wire that passes through the iron core transforms into the primary coil of the current transformer, and the passage of the current induces current in the secondary coil. Measure the current flowing through the line being tested so that the ammeter attached to the secondary coil can display a reading. By changing the gear of the switch, the clamp meter's ranges can be adjusted. However, using power while changing gears is prohibited. The clamp meter typically has an accuracy of 2.5 to 5 grades, which is not very high. The meter has switches with various ranges for the functions of measuring voltage and different levels of current for ease of use.
Make sure to clamp the wire(s) being tested when using a clamp ammeter to measure current. Current cannot be detected if two (parallel wires) are wedged together. Additionally, the detection error is minimal when the clamp ammeter's core (center) is employed for detection. It is more practical to utilize a line splitter when examining the power usage of home appliances. The current below 1A can be enhanced before detection since some line splitters have the capacity to amplify the detecting current by ten times. A DC clamp ammeter will show a negative number when detecting DC current (DCA), as the current will flow in the opposite direction. The status of the car's battery can be determined using this function.
Install the removed fuse core on one of the phases, measure the phase's current using a clamp ammeter, and then disconnect the neutral line from the AC contactor that regulates the low-voltage line at the distribution transformer. The acquired current is the phase's leakage current. In the same order, measure the leakage current of the other leakage phases.The clamp ammeter gear should be set to the high current gear when testing; if the detection value is low, switch the gear of the clamp ammeter to the mA gear for detection. This will prevent large current damage to the meter caused by the occurrence of phase wire grounding on the line (such as someone using the one-line-one-place method to steal electricity, etc.).
After identifying the phase line that has a leak, the procedure for locating the leak is to put the phase line to be checked into the fuse core at the distribution transformer, disconnect the fuses for the neutral line and the other two phases, and then use it to climb the pole. The clamp ammeter locates the leaking point by detecting the live phase wire. The middle of the line can be chosen for the boarding pole position to increase efficiency. The line segment where the leakage is suspected is found after it is determined by detection whether the leaking point is in the first half or second half of the line.The detection range is reduced analogously. In order to pinpoint the exact location of the leakage, detect the phase wire support insulator within the specified small range and the phase wire of the user connection line connected to the phase wire within the range (this can be done on the ground or simultaneously with the insulator detection).
The clamp ammeter can be used to find low-voltage user connection lines within the suspected range while low-voltage line power transmission is taking place. When conducting testing, the clamp ammeter's jaws should be simultaneously loaded with the phase and neutral wires of single-phase users as well as the three phase wires and neutral wires of three-phase users. The phasor sum of the load current magnetic flux is zero at this time if there is no leakage fault, and the clamp ammeter's indication is also zero at this time; if there is a leakage current, the clamp ammeter can identify it.
The best way to determine whether there is any leakage in the user's internal lines and equipment is to measure the leakage current at the user's power inlet line with a clamp ammeter while also plugging and unplugging the user's electrical devices and lamps one at a time. alterations to identify lighting and equipment with leaks. If the clamp ammeter indicates that the user still has leakage current even though all of the equipment and bulbs are in working order or the defective equipment has been removed, it is possible that the user's low-voltage line is leaking. In this case, the appropriate course of action should be taken. For the leakage fault of the pre-buried and concealed pipeline, only the treatment method of changing the line or rewiring can be adopted.
