IsConnectorConnected

import clr
clr.AddReference('RevitAPI')
import Autodesk
from Autodesk.Revit.DB import *

#На вход подаю один фемели-инстанс с коннекторами.
elem = UnwrapElement(IN[0])
conList = [x for x in elem.MEPModel.ConnectorManager.Connectors]

OUT = list()

for con in conList:
    reflist = [x for x in con.AllRefs]
    isElectrical = con.Domain == Autodesk.Revit.DB.Domain.DomainElectrical
    if  reflist and isElectrical:
        isConnected = True
    elif not(reflist) and isElectrical:
        isConnected = False
    else:
        con = None
        isConnected = None
    OUT.append([con, isConnected])