Page 155 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

Fig 7 Fig 8

Duplex lap winding : In duplex lap winding, the end lead of coil 1 is connected to the beginning lead of coil 3,
through commutator segments. The commutator pitch of two segments is maintained as shown in Figs 9a and b.
In triplex lap and quadruplex lap windings, the end leads of coil 1 are connected to the beginning leads of coil 4
and coil 5 respectively through commutator segments. In general commutator pitches
Yc = 1 segment for simplex lap winding

Yc = 2 segments for duplex lap winding
Yc = 3 segments for triplex lap winding
Yc = 4 segments for quadruplex lap winding.
Simplex wave winding : In simplex wave winding, the end lead of the coil 1 is connected to the beginning of a
coil placed at a distance equal to one pole pitch. (Fig 10)

Fig 9 Fig 10

Duplex wave winding : In duplex wave winding there is parallel combination of two simplex wave windings as
shown in Fig 11.
Triplex wave winding : Triplex wave winding will have a parallel combination of three simplex wave windings,
and so on.

The width of the brush will be such that in simplex lap or wave winding, the brush will make contact
with only one segment. The brush will contact two segments in duplex, three in triplex and four in
quadruplex. (Refer to Fig 12)

142 143

CITS : Power - Electrician & Wireman - Lesson 86-92