Basic Electrical Installation Work

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Balancing single-phase loads A three-phase load such motor has equally balanced phases since the resistance each phase winding will the same. after this point that reach the consumer’s installation. The important relationship between phase and line currents and voltages also shown.6. When connecting single-phase loads to a three-phase supply, care should taken distribute the single-phase loads equally across the three phases that each phase carries approxi- mately the same current.Polyphase three-phase electrical systems 225 At the main’s intake position, the supplier will provide sealed HBC fuse and sealed energy meter measure the consumer’s electricity consump- tion. Equally distributing the single-phase loads across the three-phase supply known ‘balancing’ the load. lighting load of 18 luminaires would ‘balanced’ six luminaires were connected each of the three phases.c. 11. Delta connection also used to 400V Three-phase and neutral load Brown phase Black phase Grey phase Blue neutral Substation transformer 11kV/400V 11kV 400V 400V Three-phase load 230V Single- phase load 230V Single- phase load 230V Single- phase load 400V Single- phase load FIGURE 11. . Therefore, the current taken each phase will equal. The square root 3 (兹3) simply constant for three-phase circuits, and has value 1.732.5 Three-phase four-wire distribution. Star and delta connections The three-phase windings a. The delta connection used for electrical power transmission because only three conductors are required. generator may star connected or delta connected shown Fig