There are several types of IDMT (Inverse Definite Minimum Time) curves, including:
Normal Inverse (NI): This curve is used for normal system conditions and has a moderate slope.
Very Inverse (VI): This curve is used for systems with high fault currents and has a steep slope.
Extremely Inverse (EI): This curve is used for systems with very high fault currents and has a very steep slope.
Long Time Inverse (LTI): This curve is used for systems with slow fault clearing times and has a shallow slope.
Instantaneous (I): This curve is used for systems with instantaneous fault clearing times and has a slope of infinity.
All IDMT curves are defined by a set of parameters, including the current setting, the time multiplier, and the curve type. The current setting and time multiplier determine the point at which the curve intersects the time axis, while the curve type determines the slope of the curve.