Application and Precautions of 10 KV Insulation Resistance Tester Megger

First of all, let's talk about the selection of megger of 10kV insulation resistance tester. For equipment with an additional voltage of less than 500V, select a megger (megger) of 500V or 1000V, and a megger of 1000V 2500V for equipment with an additional voltage of more than 500V.Application method of megger:

The megger (megger) has three measuring end buttons, one is the line end button (L), the other is the grounding end button (E), and the other is the shielding end button (g). Generally, when measuring the insulation resistance of photos or power lines to the ground, only l and e terminals are used, and the wiring is shown in the left figure below. The "L" end is connected to the "fire" or "phase" end of the tested equipment, and the "e" end is connected to the "ground" end of the tested equipment. When measuring the insulation resistance of the cable to the ground or the leakage current of the tested equipment is severe, use the "g" terminal button. The following figure on the right shows the wiring diagram of measuring cable insulation resistance.

After the line is connected, turn the generator crank of the unstable meter clockwise to make the voltage announced by the generator rotor available for measurement. The rotating speed of the crank should be slow and fast. When the rotating speed reaches a certain value, keep the rotating speed uniform and stable. (generally, the speed of ordinary megger is about 120 revolutions). When the generator speed of the megger is stable, the pointer on the dial is also stable. At this time, the value indicated by the pointer is the measured insulation resistance value.matters needing attention:Before measurement, conduct an open circuit and short circuit test on the megger (megger) of 10kV insulation resistance tester to check whether the megger is in good condition. If the two connecting wires are open circuited, gently swing the handle, and the pointer should point to "". At this time, if the two connecting wires are short circuited, the pointer should be at "0", indicating that the megger is good and whether there is an error in the megger.

The tested equipment shall be disconnected from the power supply, and the capacitive equipment shall be fully discharged to ensure personal safety and accurate measurement.During telemetry, no one can work on the tested equipment.When measuring motors, transformers, cables and capacitors with large capacitance, there should be a certain charging time, and the larger the capacity, the longer the charging time. Generally, the reading after the megger rotates for one minute is taken as the standard. Discharge immediately after measurement to ensure safety. The method of discharge is to take off the ground wire used in the measurement from the megger and short-circuit it on the measured object.

It is forbidden to measure insulation on lightning or equipment adjacent to high-voltage conductors. It can be measured only when the equipment is not electrified and may not be electrified by other power sources.Do not touch the measuring part of the equipment or the terminal of the megger by hand before the megger stops rotating. When removing the wire, do not directly touch the exposed part of the lead.