METHOD FOR JUDGING VARNISH IMPREGNATION STATE

摘要

A method for judging the varnish impregnation state of a core assembly (1) obtained by disposing an insulation paper (31) and a coil (4) in a slot (21) of a motor core (2) and impregnating the coil (4) and the slot (21) with a varnish (5) by nondestructive inspection. An AC voltage (E) is applied between the motor core (2) and the coil (4) for the core assembly (1) and the dielectric loss tangent tand of the core assembly (1) is determined. If the value of tand is not larger than a predetermined reference value of acceptable product, a decision is made that the varnish impregnation state of the core assembly (1) is normal.