5.6.6 Motors wound for star-delta starting
The connection of Grundfos submersible motors
wound for star-delta starting appears from the table
below and fig. 12.
Connection
PE
U1
V1
W1
W2
U2
V2
Check the direction of rotation as described in
section
5.6.4 Checking of direction of
PE
L1
L2
W2 U2
PE U1
V1
3
Fig. 12
Motors wound for star-delta starting
If star-delta starting is not required, but direct-on-line
starting is, the submersible motors must be
connected as shown in fig. 13.
PE
L1
W2 U2
PE U1
V1
Fig. 13
Motors wound for direct-on-line starting
16
Grundfos 6" motors
Yellow/green
Brown
Black
Grey
Brown
Black
Grey
rotation.
L3
V2
W1
M
L2
L3
V2
W1
M
3
5.6.7 Connection in the case of unidentified cable
marking/connection
If it is unknown where the individual leads are to be
connected to the mains in order to ensure the correct
direction of rotation, proceed as follows:
Motors wound for direct-on-line starting
Connect the motor to the mains as is expected to be
right.
Then check the direction of rotation as described in
section
5.6.4 Checking of direction of
Motors wound for star-delta starting
Determine the windings of the motor by means of an
ohmmeter, and name the lead sets for the individual
windings accordingly: U1-U2, V1-V2 and W1-W2.
See fig. 14.
Fig. 14
Unidentified cable marking/connection -
motors wound for star-delta starting
If star-delta starting is required, connect the leads as
shown in fig. 12.
If direct-on-line starting is required, connect the
leads as shown in fig. 13.
Then check the direction of rotation as described in
section
5.6.4 Checking of direction of
5.6.8 Soft starter
Grundfos only recommends the use of soft starters
which control the voltage on all three phases and
which are provided with a bypass contact.
Ramp times: Maximum 3 seconds.
For further details, please contact your soft starter
supplier or Grundfos.
rotation.
rotation.