Operation test steps of transformer insulation resistance tester:

(1) The megohmmeter should be selected according to the voltage level of the equipment. For transformers ranging from 10KV to 35KV, a 2500V megohmmeter should be selected

(2) Before measuring insulation resistance, the power supply of the tested equipment should be cut off and short-circuit discharge should be carried out. The purpose of discharge is to ensure the safety of personnel and equipment, and to ensure accurate measurement results;

(3) The connection of the shaking table should be two separate single wires with good insulation (two colors), and the two wires should not be tangled together, so as not to make contact with the ground and avoid errors caused by poor insulation of the wires;

(4) Before measurement, conduct an open circuit and short circuit test on the shaking table to check if it is in good condition. If the transformer insulation resistance tester opens the two connecting wires and shakes the handle, the pointer should point to ∞ (infinity). If the two connecting wires are instantly short circuited, the pointer should point to 0, indicating that the shaking table is in good condition. Otherwise, the shaking table will have errors;

(5) The wiring method for shake testing the insulation resistance of the primary winding to the secondary winding and ground (shell):

Short circuit the three-phase terminals of the primary winding, including lU, lV, and 1W, with bare copper wire for connection to the "L" terminal of the megohmmeter; Short circuit the secondary winding terminals N, 2U, 2V, 2W and ground (earth crust) with bare copper wire, and connect them to the "E" terminal of the megohmmeter; When necessary, to reduce the impact of surface leakage on measurement values, bare copper wire can be wrapped around the porcelain skirt of the primary side porcelain sleeve for a few turns, and then connected to the "G" end of the megohmmeter with insulated wire;

(6) The wiring method for shake testing the insulation resistance of the secondary winding to the primary winding and ground (shell) is to short-circuit the 2U, 2V, 2W, and N terminals of the secondary winding with bare copper wire. To be connected to the "L" end of the megohmmeter; Short circuit the three-phase terminals 1U, 1V, 1W of the primary winding and the ground (shell) with bare copper wire, and connect them to the "E" terminal of the megohmmeter; If necessary, to reduce the impact of surface leakage on measurement values, bare copper wire can be wrapped around the porcelain skirt of the secondary side porcelain sleeve for a few turns, and then connected to the "G" end of the megohmmeter with insulated wire.

(7) During measurement, hold the outer shell of the shaking table with one hand (to prevent shaking of the table). When the pointer indicates 0, the shaking should be stopped immediately to avoid burning the watch;

(8) When measuring, the shaking table should be placed in a horizontal position, and the shaking handle of the generator should be rotated at a speed of about 120 revolutions per minute. Read one number (R15) at 15 seconds and another number (R60) at 60 seconds, and record the shaking measurement data.