def PhaseWtSum(G2frame, histo):
    """
    Calculate sum of phase mass*phase fraction for PWDR data (exclude magnetic phases)
    
    :param G2frame: GSASII main frame structure
    :param str histo: histogram name
    :returns: sum(scale*mass) for phases in histo
    """
    Histograms, Phases = G2frame.GetUsedHistogramsAndPhasesfromTree()
    wtSum = 0.0
    for phase in Phases:
        if Phases[phase]['General']['Type'] != 'magnetic':
            if histo in Phases[phase]['Histograms']:
                if not Phases[phase]['Histograms'][histo]['Use']:
                    continue
                mass = Phases[phase]['General']['Mass']
                phFr = Phases[phase]['Histograms'][histo]['Scale'][0]
                wtSum += mass * phFr
    return wtSum
