Starting Up The Product; Preparing For Startup - Grundfos MTR Montage- Und Betriebsanleitung

6.2.2 Mains-voltage-dependent conditions
200-240 V
No output filters are required for frequency-converter-
operated motors with mains voltages up to 240 V.
380-500 V
For frequency-converter-operated motors with a
power cable length less than 25 m and a mains
supply up to 460 V, no additional motor protection
against voltage peaks is required. For frequency-
converter-operated motors with a power cable length
of more than 25 m or a mains supply higher than 460
V, sine-wave filters are required.
500 V and higher
Always use sine-wave filters for motors marked with
500 V or higher voltages.
Motors with reinforced insulation can be
supplied as an option. These motors are
according to IEC 60034-25, and therefore
there is no need for sine-wave filters. This
do not eliminate the requirement for insula-
ted bearings from frame size 225.
Exception
• Protect Grundfos motors types MG 71 and MG 80
(up to 1.1 kW/2-pole and up to 0.75 kW/4-pole) for
supply voltages up to and including 440 V without
phase insulation against voltage peaks above 650
V between the supply terminals.
• If you use MG 71 and MG 80 without phase
insulation for input voltages above 240 V, it
requires that you use sine-wave filters at the
output of the frequency converter.
MG 71 and MG 80 with phase insulation for use with
variable frequency drives are available as standard
products.
Motors supplied by Grundfos
You can connect all three-phase MG motors with
phase insulation to a frequency converter.
Other motor makes than those supplied by
Grundfos
Contact Grundfos or the motor manufacturer.
14
6.2.3 Phase insulation, MG 71 and 80
MG motors, frame sizes 71 and 80, do not have
phase insulation as standard. The motors are not
suitable for frequency converter operation as they are
not protected against the voltage peaks caused by
the frequency converter operation. Only motors with a
rated voltage equal to 460 V or above have phase
insulation.
Frequency converter operation of MG mo-
tors without phase insulation will cause
damage to the motor.
We recommend that you protect all other motors
against voltage peaks higher than 1200 V by 2000 V/
μsec.
You can eliminate the above disturbances, that is
both increased acoustic noise and detrimental voltage
peaks, by fitting an LC filter between the frequency
converter and the motor.
For further information, contact the frequency
converter or motor supplier.

7. Starting up the product

CAUTION
Too high pressure and leakage
Minor or moderate personal injury
‐
Do not run the product against a
closed outlet valve for more than ap-
proximately 5 minutes.

7.1 Preparing for startup

• Make sure that all pipe connections are tight,
stress-free and sealed.
• Make sure that the pump is immersed to the
recommended level and that it is partly filled with
liquid.
• Make sure that the liquid level in the tank is above
the minimum immersion depth.
• Make sure that the strainer or chip trays are not
blocked by impurities.
• Make sure that all safety equipment is installed
and tested for functionality.