Standard for Installation of Fire Safety Devices based on Use and Occupancy Article 127

Wiring of automatic fire alarm equipments shall comply with the following provisions in addition to Regulations for Installation of User's Electricity Device:1.Signal loop of normally opened detectors shall employ serial connection, and terminal resistor shall be attached for the fire signal-receiving switchboard to perform automatic detection of loop disconnection.2.Where Type P signal receiving switchboard employs the wiring mode of several divisions sharing a same public line, the number of the divisions shall be not more than 7.3.Detector loop resistance of Type P signal receiving switchboard shall be less than 50Ω4.A 250V insulation ohmmeter shall be used to measure the insulation resistance between wires of power supply circuit as well as between the wire and the earth. Where the voltage to earth is not more than 150V, the resistance shall be not less than 0.1MΩ; where the voltage to earth exceeds 150V, the resistance shall be not less than 0.2MΩ. A 250V insulation ohmmeter shall also be used to measure the insulation resistance between loop wires of the detector as well as between the wire and the earth, and in each fire alarm division the resistance shall be not more than 0.1MΩ.5.Where the wire is buried out the door or is likely to be immersed by water, cable coated by metal pipe or plastic wire conduit shall be used, and a distance not less than 30cm shall be kept between the signal cable and the electric wire.