Yes. Megger of 500 volts, the DC voltage generated by the DC generator in the meter is 500 volts. Current intensity and voltage are the key factors that affect the speed of water decomposition. Higher current and voltage will cause the rate of water decomposition to accelerate. . Usually, the household DC voltage of 48V is the safe voltage range for water decomposition, and the DC voltage of 500V is higher than 48V, so the electricity generated by the 500V meter can break down the water.
How to use electrician megger
The method of using electrician megger is as follows: Web link
1. Select the appropriate megometer: Choose an appropriate megometer according to the voltage level and measurement requirements of the electrical equipment to be measured. The range of the megometer should be able to cover the range of insulation resistance and de earth resistance of the electrical equipment tested. Prepare tools and materials: Prepare the necessary tools and materials such as megger, wire nuts, test leads, pens, and notebooks.
2. Check the megger: Before using the megger, you should check whether the appearance of the megger is intact and whether the accessories are complete to ensure that the megger can work normally. Connect the test lead: Connect one end of the test lead to the L (line) terminal of the megger and the other end to the test point of the electrical equipment under test.
3. Start measurement: Turn the megometer switch to the measurement position and observe the megometer pointer indication. If the pointer points to infinity, it means that the insulation resistance or grounding resistance of the electrical equipment under test is infinite and the circuit is isolated; if the pointer is pointingbetween tens and hundreds of ohms, this means that the insulation resistance or grounding resistance; tested electrical equipment exists. A malfunction or undesirable condition requires further inspection and repair.
Relevant knowledge of electrician flip meter
1 The structure of flip meter: The flip meter mainly consists of a manual generator , a measuring device. circuit, an indicator and a test Made up of wires, etc. The manual generator is the main component of the meter. It generates high voltage by rotation; the measuring line is the line that connects the manual generator and the indicator, which transmits the high voltage to the indicator; indicator is the component used to display; measurement results; Test leads are wires used to connect the megger and the electrical equipment under test.
2. Precautions for megger: When using the megger, you need to pay attention to safety issues. First of all, you should avoid using the meter in humid environments, high temperatures or with explosive gases. Second, you should avoid touching or approaching the electrical equipment being tested during the measurement process to avoid electric shock accidents. It is also necessary to pay attention to the use and precautions of the oscillator to avoid damage to Fanxiao equipment due to improper operation.
3. Maintenance of megger: When using the megger, you should pay attention to maintenance. If the manual generator is used frequently, it should be inspected and maintained regularly to ensure that the height of the machine can operate normally. If the meter is not used frequently, it should be stored in a dry, ventilated place and inspected and maintained regularly.
Principle of the shake table
The shake tableAlso called megohmmeter, its use is as follows:
1. Before measurement, the megger should be held in a horizontal position, hold the meter body with your left hand and shake the megger rocker with your right. hand at a speed of about 120 rpm, the pointer should point to infinity (∞), otherwise it means that the megger is defective.
2. Before measurement, the power supply to the electrical apparatus and circuit under test should be cut off, and the relevant components should be temporarily grounded and discharged to ensure the safety of people, the megger and the accuracy. measurement results.
3. The wiring must be correct when measuring. The megger has three terminals (L, E, G). When measuring loop resistance to ground, end L is connected to conductor exposed of the loop and the end E is connected to the ground wire or the metal shell when measuring the insulation resistance of the loop, the first and ; the last ends of the loop are connected to L and E respectively; cable insulation is measured when measuring resistance, in order to prevent leakage current on the cable surface from affecting the measurement accuracy, the cable shielding layer should be connected to the terminal G.
4. The flexible measuring wire coming from the megger terminal should be well insulated and a proper distance should be maintained between the two wires and between the wire and the ground to avoid affecting the measurement accuracy.
5. When shaking the megger, do not touch the megger terminals and the circuit under test with your hands to avoid electric shock.
6. After shaking the megger, do not short the terminals to avoid damage.
7. Don't shakes the megger too long.
Principle of the megger:
There are three terminals on the megger: one is "L" which is the line terminal, the other "E" is the ground terminal, and the other "G" is the shield terminal. The correct connection method is: the wire terminal "L" is connected to the conductor of the device under test, the ground terminal "E" is connected to the grounded device shell, and the other “G” is the shield terminal. The shield terminal "G" is connected to the insulating part of the device under test.
Because the insulation degree between the internal wire of the "E" terminal and the case is lower than that between the "L" terminal and the case, when the megger is placed on the ground and used in the correct wiring method, "E" "The insulation resistance between the terminal and the instrument shell and the shell and ground is equivalent to a short circuit and will not cause errors.
When "L" and "E" are connected toReversely, the insulation resistance of "E" to ground is connected in parallel with the measured insulation resistance, which makes the measurement result smaller and results in a larger error. the measure.
Detailed information:
Shaking table notes:
< p > 1. It is prohibited to measure insulation resistance during lightning or near high voltage equipment. It can only be measured when the equipment is not charged and there is no induced electricity.2. When measuring the insulation resistance of the equipment, the power supply to the equipment should first be turned off. Equipment containing inductors and capacitors should be discharged first. Off-duty personnel must request corresponding work tickets before they can work.
3. The oscillator must be placed horizontally. Before wiring, youBe sure to shake the oscillator and see if the pointer is at “∞”. Then short-circuit terminals L and E and slowly shake the watch. The needle should be at zero. After open circuit and short circuit tests, the megger is confirmed to be intact before measurement can be made.
4. The megger wire should be a multi-stranded soft wire and the two wires should not be twisted together to avoid inaccurate measurement data.
5. After the megger measurement is completed, the measured object should be unloaded immediately. Before the megger stops rotating and the measured object is discharged, do not touch the measuring part of the measured object or. disassemble it with your hands to avoid electric shock.
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