def phs3mvasc(Vth, Zseq, Rf=0, Sbase=1):
    """
    Three-Phase MVA Short-Circuit Calculator
    
    Calculator to evaluate the Short-Circuit MVA of a three-phase fault given the system
    parameters of Vth, Zseq, and an optional Rf. Uses the formula as follows:
    
    .. math:: MVA_{sc} = \\frac{\\left|V_{th}^2\\right|}{|Z_1|} * Sbase
    
    Parameters
    ----------
    Vth:        complex
                The Thevenin-Equivalent-Voltage
    Zseq:       list of complex
                Tupple of sequence reactances as (Z0, Z1, Z2)
    Rf:         complex, optional
                The fault resistance, default=0
    Sbase:      real, optional
                The per-unit base for power. default=1
    
    Returns
    -------
    MVA:        real
                Three-Phase Short-Circuit MVA.
    """
    MVA = abs(Vth) ** 2 / abs(Zseq[1]) * Sbase
    if Sbase != 1:
        MVA = MVA * 1e-06
    return MVA
