CAUTION
Danger of injury from moving parts
After a power failure or a standstill as a result of overheating, the motor restarts automatically. There
is a risk of injury to fingers and hands if they enter the operating range of rotating parts.
► Safely disconnect motor from the mains.
► Secure the motor against reactivation.
► Dismantle the vacuum pump for inspection, away from the system if necessary.
NOTICE
Risk of damage from excess voltage
Incorrect or excessive mains voltage will destroy the motor.
► Always observe the motor rating plate specifications.
► Route the mains connection in accordance with locally applicable provisions.
► Always provide a suitable mains fuse to protect the motor and supply cable in the event of a fault.
– Pfeiffer Vacuum recommends the circuit breaker type "K" with slow tripping characteristic.
NOTICE
Property damage from high starting torque
The specific load behavior of the vacuum pump requires direct on-line starting at full motor power.
Engine damage occurs if a different starting circuit is used.
► Always start the motor directly.
►
Never
use a star-delta start-up circuit.
5.5.1 Connect three phase motor with 6-pin terminal board
There are 2 different circuit configurations:
● Delta connection for low voltage
● Star circuit for high voltage
W2
U1
U2
V2
V
V1
W1
L1
L2
L3
Fig. 8:
Delta connection
The 3 wires are connected in series. Their connection points are connected to the mains. The voltage
per phase is equal to the mains voltage, while the mains current is √3 times the phase current. The del-
ta connection is marked with the
∆
symbol. The voltage between the incoming mains supply lines is
called mains voltage. The mains current is the current flowing in the incoming supply lines.
Connect the three phase motor with delta connection
► Connect the three phase motor according to the connection diagram.
V
L1
L2
L3
W2
U1
U2
V2
V1
W1
Fig. 9:
Star circuit
The ends of the 3 phases are connected in the star point. The terminal voltage is √3 times the phase
voltage, the mains current is equal to the phase current. The star circuit is marked with the
Y
symbol.
Installation
26/62
