Operation procedure of transformer insulation resistance test?

Answer:

Wiring method for measuring insulation resistance of primary winding to two winding and ground (shell):A three-phase winding terminal lU, lV, 1W with bare copper wire short circuit for ground megger "L" end; two winding ends of N, 2U, 2V, and 2W (crust) with bare copper wire short circuit, connected to the megohmmeters "E" end; when necessary, after in order to reduce the influence of surface leakage measurements can be wound a few turns in a side ceramic casing porcelain skirt with bare copper wire and insulation wire is connected with the megohmmeter "G" end;

Before measuring will shake table an open circuit and short circuit test, check the shake table is good, if the two connecting lines open shake the handle pointer should refers to the infinity (infinite), then if the two line head short answer, the pointer should refer to in 0, when the shaking table is good well, it is the error of shake table;

Shaking table should be connected to the good insulation of the two separate single line (preferably two-color), two lines do not tie together, it is best not to make contact with the ground, so as not to cause bad insulation due to poor wiring;

The meter shall be selected according to the voltage level of the equipment, and the 2500 volt shaker shall be used for the 10KV-35KV transformer

Before measuring the insulation resistance, the power supply of the equipment under test shall be cut off and short circuit discharge shall be carried out. The purpose of discharging is to ensure the safety of the personal and the equipment and to make the measurement result accurate;