The delta connection used for electrical power transmission because
only three conductors are required.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.c. The square root 3
(兹3) simply constant for three-phase circuits, and has value 1. lighting load of
18 luminaires would ‘balanced’ six luminaires were connected each
of the three phases. 11.
Star and delta connections
The three-phase windings a. 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. 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. The important relationship between
phase and line currents and voltages also shown.
. Equally distributing the single-phase loads across
the three-phase supply known ‘balancing’ the load.6. generator may star connected or
delta connected shown Fig. after this point that reach the consumer’s installation.732.5
Three-phase four-wire distribution.
Balancing single-phase loads
A three-phase load such motor has equally balanced phases since the
resistance each phase winding will the same
