12
Installation
Three-phase motor
The three-phase current motor circuit
The connections U1 - L2, V1 - L1 and W1 - L3 result in a clockwise rotation of the motor
shaft as seen looking towards the motor fan.
Delta Connection
The three coils are connected in series with the connection point connected to the mains.
The voltage of each coil is the same as the mains voltage whereas the mains current is
the cube root of the coil current. Delta connections are denoted by the symbol
∆
. The
voltage between the mains supply lines is called mains voltage. The mains current is the
current which flows in the supply lines.
Fig. 5:
Motor coil and connecting plate of Delta Connection (for low voltage)
Star Connection
The ends of the three coils are connected at the star center. The terminal voltage is the
cube root of the coil voltage; the mains and the coil current are the same. Star connec-
tions are denoted by the symbol
Y
.
Fig. 6:
Motor coil and connecting plate of Star Connection (for high voltage)
Inspection of the direction of rotation
For pumps with three-phase motors, it is necessary to check the direction of rotation!
Remove the locking cap from the exhaust flange (if existing).
Switch the pump on briefly (from 2 to 3 sec.).
– The motor and motor fan must turn in a clockwise direction (see the arrow on the
support stand).
If the direction of rotation is incorrect: Swap two phase contacts at the connecting ca-
ble.
Fill up the operating fluid.
W2
U1
L1
V2
V1
W1
U2
L3
L2
W2
U2
V2
U1
V1
W1
L1
L2
L3
W2
U1
L1
V2
V1
W1
U2
L3
L2
W2
U2
V2
U1
V1
W1
L1
L2
L3
CAUTION
Operating fluids may leak out!
If the direction of rotation is incorrect, there is a danger that operating fluids may leak at
the vacuum flange.
Always check the direction of rotation before filling in operating fluid.
