Grundfos SP Installation And Operating Instructions Manual page 13

5.7.2 Grundfos motors, direct-on-line starting
The connection of Grundfos submersible motors wound for direct-
on-line starting appears from the table below and fig. 14.
Mains
Grundfos 4" and 6" motors
PE
L1
L2
L3
Check the direction of rotation as described in section
5.7.1 Checking of direction of rotation.
PE L1
PE U
M
3
Fig. 14 Grundfos motors, direct-on-line starting
5.7.3 Grundfos motors, star-delta starting
The connection of Grundfos submersible motors wound for star-
delta starting appears from the table below and fig. 15.
Connection
PE
U1
V1
W1
W2
U2
V2
Check the direction of rotation as described in section
5.7.1 Checking of direction of rotation.
PE L1
W2 U2
PE U1
Fig. 15 Grundfos motors, star-delta starting
Cable/connection
PE (yellow/green)
U (brown)
V (black)
W (grey)
L2 L3
V W
Grundfos 6" motors
Yellow/green
Brown
Black
Grey
Brown
Black
Grey
L2 L3
V2
V1 W1
M
3
If star-delta starting is not required, but direct-on-line starting is,
the submersible motors should be connected as shown in fig. 16.
PE L1
W2 U2
PE U1 V1
Fig. 16 Grundfos motors, direct-on-line starting
5.7.4 Connection in the case of unidentified cable marking/
connection (Franklin motors)
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 pump to the mains as is expected to be right.
Then check the direction of rotation as described in section
5.7.1 Checking of direction of rotation.
Motors wound for star-delta starting
The windings of the motor are determined by means of an
ohmmeter, and the lead sets for the individual windings are
named accordingly: U1-U2, V1-V2 and W1-W2, see fig. 17.
U1 U2
V1
Fig. 17 Unidentified cable marking/connection – motors
wound for star-delta starting
If star-delta starting is required, the leads should be connected as
shown in fig. 15.
If direct-on-line starting is required, the leads should be
connected as shown in fig. 16.
Then check the direction of rotation as described in section
5.7.1 Checking of direction of rotation.
5.7.5 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 switch.
Ramp times: Maximum 3 seconds.
For further details, please contact your soft starter supplier or
Grundfos.
L2 L3
V2
W1
M
3
V2
W1W2
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