6.7.4 Connection in the case of unidentified cable
marking/connection (Franklin motors)
If you do not know 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
6.7.1 Checking the 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, W1-W2. See fig. 18.
Fig. 18 Unidentified cable marking/connection - motors wound
for star-delta starting
If star-delta starting is required, connect the leads as shown in
fig. 16.
If direct-on-line starting is required, connect the leads as shown
in fig. 17.
Then check the direction of rotation as described in section
6.7.1 Checking the direction of
6.7.5 Soft starter
We only recommend 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, contact your soft starter supplier or Grundfos.
6.7.6 Frequency converter operation
Three-phase MS motors can be connected to a frequency
converter.
To enable the monitoring of the motor
temperature, we recommend that you install a
Note
Pt100/Pt1000 sensor together with a PR5714 or
CU 220 (50 Hz).
Permissible frequency ranges: 30-50 Hz and 30-60 Hz.
Ramp times: Maximum 3 seconds for start and stop.
Depending on the type, the frequency converter may cause
increased acoustic noise from the motor. Furthermore, it may
expose the motor to detrimental voltage peaks. This can be
abated by installing an LC filter between the frequency converter
and the motor.
For further details, contact your frequency converter supplier or
Grundfos.
14
rotation.
rotation.
7. Installation
We recommend that you first fit a 50 cm long pipe to the pump to
facilitate handling of the pump during installation.
Lift the pump to vertical position before removing
Caution
it from the wooden box.
Fig. 19 Lifting the pump into vertical position
7.1 Fitting the motor to the pump
When the pump part and the motor are supplied as separate units
(long pumps), fit the motor to the pump as follows:
1. Use pipe clamps when handling the motor.
2. Place the motor in vertical position at the borehole seal.
See fig. 20.
Fig. 20 Motor in vertical position