Connect the three phase motor with star circuit
► Connect the three phase motor according to the connection diagram.
5.5.2 Connect three phase motor with 9-pin terminal board
There are 2 different circuit configurations:
● Double star circuit for low voltage
● Star circuit for high voltage
L1
L2
L3
W2
W3
W1
U2
V3
V1
V2
U3
U1
V
Fig. 10:
Terminal board for low voltage
The parallel-switched winding strands are arranged in a star layout. The mains current is distributed to
two coils in each case.
Connect the three phase motor with double star circuit
► Connect the three phase motor according to the connection diagram.
L1
L3
L2
W2
W3
W1
V2
V3
V1
U2
U3
U1
V
Fig. 11:
Motor winding and terminal board for high voltage
The series-switched winding strands are arranged in a star layout. The mains voltage must be higher by
a factor of 2, the mains current is halved compared to the double star circuit.
Connect the three phase motor with star circuit
► Connect the three phase motor according to the connection diagram.
5.5.3 Checking the direction of rotation
NOTICE
Equipment damage from incorrect direction of rotation
The direction of rotation must be checked on vacuum pumps with three phase motors. If the vacuum
pump has an incorrect direction of rotation, damage may be caused to the pumping system after a
short time.
► Determine the intended direction of rotation based on the arrow sticker.
► Fill in the operating fluid only after that.
Procedure
1. Switch on the vacuum pump briefly (2 to 3 seconds).
– The motor and motor fan must rotate counter-clockwise (see the arrow on the fan cover).
2. If the direction of rotation is incorrect, exchange the 2 phases on the connection cable.
5.5.4 Setting the motor protection switch
Motor protection switches are current-dependent protective devices for the drive motors. Motor protec-
tion switches with slow tripping characteristics are suitable.
Installation
27/62
