Grundfos MS Serie Instrucciones De Instalación Y Funcionamiento página 15

5.6.3 3-wire motors
MS 402 3-wire motors incorporate motor protection
and must be connected to the mains via a Grundfos
SA-SPM 5, 7 or 8 control box without motor
protection.
MS 4000 3-wire motors must be connected to the
mains via a Grundfos SA-SPM 5, 7 or 8 control box
incorporating motor protection.
When a conventional motor-protective circuit breaker
is used, the electrical connection must be carried out
as described below.
5.6.4 Checking of direction of rotation
When the motor has been connected to the power
supply, determine the correct direction of rotation as
follows:
1. Add a few drops of water to the shaft seal before
starting.
2. Start the motor and check the direction of rotation
by watching the motor shaft. For Grundfos SP
pumps, the direction of rotation must be counter-
clockwise.
3. Compare the result from item 1 with the demand
of the pump.
4. Interchange two of the phase connections if the
direction of rotation is wrong. In the case of
motors wound for star-delta starting, exchange
U1 by V1 and U2 by V2.
5.6.5 Motors wound for direct-on-line starting
The connection of Grundfos submersible motors
wound for direct-on-line starting appears from the
table below and fig. 11.
Cable/connection
Mains
Grundfos 4" and 6" motors
PE PE (yellow/green)
L1
L2
L3
Check the direction of rotation as described in
section 5.6.4 Checking of direction of
PE L1 L2
PE U
M
3
Fig. 11 Motors wound for direct-on-line starting
U (brown)
V (black)
W (grey)
rotation.
L3
V W
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