How to find out the leakage of tubular heater with Multimeter?
First recall the stainless steel electric tubular heater failure phenomenon, what are the obvious characteristics; secondly, observe whether there are intuitive fault points from the surface, and then carry out the next step inspection.
1. First, disconnect the main isolating switch of the user's power incoming line, and turn off all power loads of the user.
2. Put the position of digital multimeter on the 200m block of Ohm gear. One probe is placed on one of the two outgoing lines on the load side, and the other probe touches the wall to touch the grounding wire or temporary grounding wire. After the data displayed on the multimeter is stable, the insulation resistance value of the main line is read out. If the insulation resistance value is less than 0.5 megohm, there is a problem with the main circuit. If the insulation resistance is more than 0.5 megohm, it can be ruled out that there is a problem with the main circuit. Use the same method to measure another wire and check the value to see if there is something wrong with the main line.
3. Check the insulation resistance value of shunt and each electric appliance, and use the same method to detect one by one until the fault point is found.
Precautions for operation of universal meter:
1. When using the 200m gear of the ohm block of the multimeter, pay attention not to touch the metal part of the probe by hand during the measurement, which will make the reading inaccurate.
2. When measuring each electrical equipment, pay attention to discharge first to prevent the capacitive current in the electrical equipment from injuring people.
This method is a safe way to find the fault point in the state of no electricity. However, when searching, it is necessary to disconnect not only the incoming power line, but also the zero line to avoid electric shock.
If it is to test whether an object is electrified (there is electricity to the ground), turn the multimeter to a suitable range (depending on the occasion). The black probe is grounded, and the red probe is connected to the measured object. If there is indication, the object is electrified to the ground. If measuring whether there is electric leakage to the ground wire, whether there is current in the ground wire. If it is a clamp type meter, clamp the ground wire directly. If it is an ordinary multimeter, it is necessary to cut off the ground wire. Turn off the AC current gear of the multimeter (be careful, the protection of the metal shell electrical appliances will be lost after the grounding wire is cut off). Connect the two ends of the disconnection to the two probes of the multimeter. If there is a reading, it indicates that there is leakage.