The motor insulation voltage specified in the national standard is >50MΩ, and generally the higher the better. But if what you are measuring is between phases U, V and W, it means the motor winding is open circuit. .
Megohm meter, also known as megohm resistance meter, is a megohm resistance meter used to measure the insulation resistance of various electrical equipment to prevent accidents. It is practical and reliable.
The toggle meter consists of a hand crank generator, a poll and three terminals (i.e. L: line end, E: ground end, G: shield end). It is widely used in the installation and maintenance of coal mines). . Used to check the insulation of motors, electrical devices and circuits and measure high value resistance.
Instructions for use
1. Before the measurement, the megohmmeter should be kept in a horizontal position, hold the meter body with your left hand and shake the megger rocker with your right hand. at around 120 rpm the pointer should point to infinity (∞), otherwise the megger is faulty.
2. Before measurement, the power supply to the electrical apparatus and the 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 the resistance of the loop to ground, the L end is connected to the exposed conductor of the loop and the E end is connected to the ground wire or metal shell when measuring the resistance d 'loop isolation, the first and; the last ends of the loop are connected respectivelyement to L and E; 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. Do not shake the megger for too long.
When purchasing a water cooling meter (insulation resistance tester for water cooled generators), there are two main points to note: Firstly, the meGenerator cooling method should be water cooled rather than water cooled. than air cooled. The instrument is intended for water-cooled generators only; second, select the voltage level and range. There are three main types of water jerk meters (insulation resistance testers for water-cooled generators) in the market based on voltage level: 2500V/10G, 5000V/20G and 2500 V/5000 V/20 G. They vary depending on the voltage level. and generator capacity. Make your selection. Third: Second, choose instruments that can automatically compensate and eliminate the impact of water polarization potential on measurement results. Automatically measure R15, R60 and R600 and automatically calculate absorption rate and polarization index. The test voltage is negative high voltage 2500V, and the charging capacity of 5000V is strong. Whenthe resistance (water resistance) between the winding and the water collection pipe is as low as 70kΩ, the test voltage drops <10%. The measuring range is 0-20GΩ, and the range is automatically switched. able to self-compensate and dynamically eliminate the impact of water polarization potential on test results. When the resistance between the water collection pipe and the machine base is as low as 3kΩ, the measurement accuracy can still be guaranteed.