English (GB)
8
5. Electrical connection
5.1 General
The electrical connection must be carried out by an
authorised electrician in accordance with local
regulations.
The supply voltage, rated maximum current and
cos φ are displayed on the separate nameplate that
must be fitted close to the installation site.
The required voltage quality for Grundfos MS and
MMS asynchronous submersible motors, measured
at the motor terminals, is - 10 % / + 6 % of the
nominal voltage during continuous operation
(including variation in the mains voltage and losses
in cables).
Furthermore, make sure there is voltage symmetry in
the power supply lines, that is, the difference of
voltage between the individual phases is the same.
See also section 11. Checking the motor and cable,
item 2.
If MS motors with a built-in temperature transmitter
(Tempcon) are not installed together with an MP 204
motor protection unit, they must be connected to a
0.47 μF X2 capacitor (IEC 384-14) approved for the
actual voltage. The capacitor must be connected to
the two phases to which the temperature transmitter
is connected. See fig. 6.
Fig. 6 Connection of capacitor
The motors are wound for direct-on-line (DOL) or
star-delta starting, and the starting current is
between four and six times the rated current of the
motor.
The run-up time of the motor is only about 0.1
second. Direct-on-line starting is therefore normally
approved by the power supply company.
DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before
starting any work on the product.
- Make sure that the power supply cannot
be accidentally switched on.
DANGER
Electric shock
Death or serious personal injury
- The pump must be earthed.
- The pump must be connected to an
external main switch and must be
provided with means to locking it in the
OFF (isolated) position. Type and
requirements are specified in
EN 60204-1, 5.3.2
The electrical connection must be carried
out by an authorised person in accordance
with local regulations.
TM00 7100 0696
If an MS motor with temperature
transmitter is connected to a frequency
converter, he fuse melts and the
transmitter becomes inactive. The
transmitter can no longer be reactivated,
consequently, the motor thereafter
operates like one without a temperature
transmitter.
To enable monitoring of the motor
temperature when running at frequency
converter operation, Grundfos
recommends that a Pt100 or a Pt1000
sensor be installed.
During frequency converter operation, it is
not advisable to run the motor at a
frequency higher than the rated frequency
(50 or 60 Hz). In connection with pump
operation, it is important never to reduce
the frequency (and consequently the
speed) to such a level that the necessary
flow of cooling liquid past the motor is no
longer ensured.
0.47 μF
1 = L1: Brown
2 = L2: Black
3 = L3: Grey
4 = PE: Yellow and green
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