Clamp ammeter how to check whether there is a leakage of electricity method
Through the core of the measured circuit wire becomes the primary coil of the current transformer, which passes through the current will be induced in the secondary coil of the current. Thus, the secondary coil connected to the ammeter will have an indication ----- of the current of the line under test. Clamp meter can be through the switch gear, change different ranges. But the dialing is not allowed to operate with electricity. Clamp meter general accuracy is not high, usually 2.5 ~ 5 level. In order to facilitate the use of the table, there are also different ranges of the conversion switch for measuring different levels of current and voltage measurement function.
When detecting current with a clamp-on ammeter, be sure to clip in one of the wires (wires) to be measured. If two wires (parallel wires) are clamped in, the current cannot be detected. In addition, the detection error is small when using the center (core) of the clamp ammeter. When checking the power consumption of home appliances, it is more convenient to use a line separator, and some line separators can amplify the detection current by 10 times, so currents below 1A can be amplified and then detected. When detecting direct current (DCA) with a DC clamp ammeter, a negative number is displayed if the current flows in the opposite direction. This function can be used to detect whether the vehicle's battery is in a charging state or a discharging state.
In the distribution transformer, the control of low-voltage lines, the AC contactor outlet side of the neutral line disconnected, and then has been removed from the fuse core installed in one of the phases, with a clamp ammeter to measure the phase, the measured current is the leakage current of the phase. According to the same method in turn measured the leakage current of the remaining leakage phase. In order to prevent the existence of phase line grounding (such as a line of people using a ground method of electricity theft, etc.) occurring large current damage to the instrument, the detection of the first clamp-on ammeter block on the large current block; if the detection value is very small, and then the clamp-on ammeter block converted to milliampere block detection.
Determine the existence of a leakage of the phase line, determine the location of the leakage is: in the distribution transformer, the phase line to be inspected inserted fuse core, neutral line and the remaining two-phase fuse are disconnected, boarding the pole with a clamp-on ammeter to detect the charged phase line to determine the location of the leakage. In order to improve efficiency, the boarding position can be selected in the middle of the line, through the test to determine the leakage part of the line in the first half or the second half, and then to the suspected leakage of the line section detection. And so on, to narrow the scope of detection. Finally, to determine the smaller scope of the phase line pillar insulator test, and the scope of the user connected to the phase line connected to the phase line phase line test (can be carried out on the ground, but also in the test insulator at the same time), in order to determine the leakage of the specific site.
In the case of low-voltage line power supply, you can also determine the scope of suspicion of low-voltage users connected to the household line with a clamp-on ammeter for testing. Detection, single-phase users of the phase line and the neutral line should be placed in the jaws of the clamp-on ammeter at the same time, three-phase power users of the three phase line and the neutral line should also be put into the jaws at the same time. If there is no leakage fault, then the load current flux of the phase and zero, the clamp ammeter indication is also zero; such as leakage current, the clamp ammeter can detect leakage current to.
Check the user's internal lines and equipment with or without leakage method is: the user's power inlet line with a clamp-on ammeter to measure the leakage current, while the user's power equipment, lamps and lanterns are put into exit one by one, by looking at the clamp-on ammeter leakage current to detect changes in leakage to find leakage equipment and lamps and lanterns. If all the equipment lamps and lanterns are good, or there is a leakage of equipment have been withdrawn, but the clamp-on ammeter shows that the user still has a leakage current, it may be the user's low-voltage lines there is a leakage, should be dealt with on a case-by-case basis. For pre-buried concealed pipeline leakage fault, can only be taken to change the line or rewiring of the treatment method.
