current withstand curves for the Generator

Contact the original equipment manufacturer for advice.

You see!any generator winding can deliver rated current continuously provided the temperature rise is kept within limits. That is if proper cooling arrangements are available. But, when the generator is overloaded or is supplying a fault, the current increases and thus the heating too. Damage to winding insulation is effected by heat and heat is I2t. So, overload currents and fault currents can be tolerated by the generator windings only for a brief period. Any generator manufacturer will supply this relationship of current versus time in the form of a curve. This is called WIthstand Curve for that generator. You hav eto contact the gebnerator manufacturer and obtain it.

can we get over current withstand form there? and is equal to field current at rated load..

Yes! You can very much get the over current withstand. Actually, the curve will have tolerable time in the 'Y' axis and the current as a multiple of the rated current in the 'X' axis. The curve is an exponential curve.

It is only relating armature current and not field current.,