1, transformer core grounding inspection in the removal of iron choke after taking 5 pieces, in the burr at the maximum measurement with micrometer measurement, shearing burr < 0.03mm; Long side deviation 0.15mm, short side deviation 0.03mm, width deviation 0.2mm, parallelism < 0.4mm, straightness < 0.5mm, Angle deviation 0.03.

2, to detect whether the end face of the iron core is uneven with the depth of the vernier caliper, ruler measurement of the difference between the two adjacent iron chips on the upper end face of the iron choke, should not be > 1.0mm, core column diameter sign 330 mm. Check the flatness between upper limbs of the two lower clamps. Use 3O0mm steel plate ruler and plug ruler to measure the outer side of phase A and C, and the flatness should be less than 3mm and the iron core diameter is 33Omm.

3, check the surface condition of the iron core to see the outer surface of the iron core should not be rust, but allow to be covered by the paint film rust, its area should not be greater than 20% of the visible part. The core lamination should not be wrong lamination, and overlapping edge pressing should not occur at the joints of each stage. Joint gap: when core diameter ≤ 330mm ≤ 1.5mm. Grounding check If the ground lug is connected, the iron core pair clamp and the gasket should be in the path, and the ground lug removed should be disconnected.

4. Check the appearance of the iron core. After the iron core is upright, the core column should not be obviously bent or deformed, and the inclination of the core should not be greater than 5 ‰ of the total height of the iron core. Iron core weight Check The weight of the iron core after stacking should be basically consistent with the drawing. If there is an agreement, the net weight should not exceed 0.5% of the weight specified in the drawing. After passing the no-load loss test, the new trial-produced product is allowed to deviate by + 30% compared with the standard.

5, inspection records Inspection personnel should fill in the above inspection results in the Core Testing Record. The judgment that examines a result and mark examine to outside appoint the iron core sampling that processes, above any unqualified all judge is unqualified to taste, should double spot check, examine to unqualified project 2 times still unqualified, judge this batch of products is unqualified to approve, should execute "unqualified product control program".