Revit Guides
Data Management
ELI5
zone indicator
part of indicating equipment which visually indicates the zone of origin of a alarm of fire or faultwarning BS 4422 2005 Zone Indicator in Fire Alarm Systems The zone indicator
Ze
That part of the earth fault loop impedance which is external to the circuit under consideration. For the supply cable it will be the impedance external to the installation. For
Z2
Z2 – That part of the earth fault loop impedance which comprises the impedance under earth fault conditions of the circuit protective conductor (cpc) of the circuit under consideration.
Z1
Z1 – That part of the earth fault loop impedance which comprises the impedance under earth fault conditions of the line conductor of the circuit under consideration.
Max Zs
Themaximum value of earth fault loop impedance (Zs) that will allow the protective device in a circuit to disconnect an earth fault within the prescribed time. Example: if themaximum earth
