Standard requirements for grounding of concealed door distribution boxes
148 (Grounding Conductor): Requires metallic junction boxes—and by extension, cabinet doors—to bond to ground using a designated grounding screw or clip. The conductors shall be run as multiconductor cord or cable assemblies or within raceways; or, where not subject to physical damage, they may be run as open conductors on insulators not more than 10 feet. Thread Depth: The pre-drilled thread must meet the tightening torque requirements after crimping multiple wires. Contact Surface Treatment: Coatings or oxide layers should be removed from the connection area to expose the natural metal and reduce contact resistance. 8 kV) feeder outlets of HV / MV Substations down to SEC Customer interface including KWH-Meters and meter boxes.
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