Connecting Diagrams - cemp F Serie Manual De Instrucciones

3.

Connecting diagrams

3.1 Three-phase motors
3.1 Three-phase motors
The winding of standard motors can be
connected together to form two different
connections:
- star connection
- delta connection
Star connection
GB
Connecting together the W2, U2, V2
terminals (star point) and connecting to the
mains the U1, V1, W1 terminals a star
connection is obtained.
The phase current I and the phase voltage
ph
U are the following:
ph
I = I
ph n
U = U / ED 3
ph n
where I the line current and U
n
voltage.
Delta connection
Connecting the end of each winding to the
beginning of the next winding a delta
connection is obtained.
The phase current I and the phase
ph
voltage U are the following:
ph
I = I / ED 3
ph n
U = U
ph n
Star - Delta starting
The star-delta starting is an easy way to
reduce the starting current and starting
torque.
Motors can be started with the star-delta
starting method whenever the supply
voltage correspond to the rated voltage of
the motors in delta connections.
18
is the line
n
Two speed motors
Standard two speed motors are designed for
only one rated voltage and for direct
starting.
When the speed ratio is 1/2 the standard
motors have one winding (Dahlander
connection). For the other ratios motors
have two different windings.
U2 V2 W2
U ph
I ph
U1 V1 W1
L3
L1 L2
U n
Fig. 3 A
U2 V2 W2
U ph
U1 V1 W1
L1 L2 L3
U n
Fig. 3 B
Star point
U ph
I ph
U ph
L1 L2 L3
U n
I n
I ph I ph
U ph L3
L1 L2
U n