Size of busbar chamber depends on following factors.
Total load or load current on installation Future load on installation No. of tappings provided on buabar Spare feeders provided if any Size of incoming and outgoing cable Whether bus bar is outdoor or indoor type
Bus bar chamber is required for larger installation. The electrical load of commercial installation is large therefore 3-phase 4 wire power service connection is provided to satisfy the requirement of the entire load. Thus to distribute the load on 3-phase four wire system, bas-bar chamber is used. Bus-bar is a copper or aluminum conductor (strip) to which number of inputs and number of outputs can be connected. Incoming and outgoing wires or cables are connected to bus-bar by screw and nut arrangement.