This sentence applies to generators whose cooling method is the water-hydrogen-hydrogen method, that is, water passes through the hollow conductor inside the winding of the stator. The water carries away the heat generated during the operation of the generator and obtains it. cooling effect. The stator core and rotor. There are ventilation channels inside the winding and hydrogen cooling is used.
If the temperature of the internal cooling water of the generator stator winding is higher than the temperature of the hydrogen outside the winding, condensation will form on the outer surface of the stator winding, i.e. the insulation surface. of the stator winding will become very wet, which will damage the insulation of the stator winding. As a result, the stator winding will be partially discharged and will no longer be able to function.