scope:

This specification relates to baking varnishes which shall be suitable for the impregnation of electrical windings on Service equipment such as the armature and fieldwindings of generators and motors, the coils of transformers and eleotro-magnets, or any other winding that is required to be rigid and to have a high insulation resistance between turns and earth.

The varnishes shall be suitable for use at the temperatures and with the materials normally used where Class A, Class E and Class B insulation (as deíined in B.S.2757) are specified.

The hard type is tended for use where high mechanical strength is required, e.g. to hold together windings rotating at high speed and at high temperature.

Note: In addition to their primary use referred to above, the varnishes may be used for the prior impregnation of other materials used in the manufacture of coil windings, etc. or, incidentally, as a surface finish on the metals carrying the electrical windings referred to above.