Vogt NM Series, Руководство по обслуживанию, Страница: 15 / 30

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Start-up
It is important to check before the first start-up that the technical specifications of the motor, which come on the nameplate,
correspond to the technical characteristics required by the pump and those of the place where the motor is going to operate.
Verify that:
• The characteristics of the mains supply, voltage, number of phases, frequency, and amperage match those of the
motor.
•
The electrical panel must be suitable for the type of motor drive, direct start or star-delta.
•
The degree of insulation and protection of the motor must correspond to the conditions in which it will operate.
• Before final start-up, it is necessary to check the direction of rotation to prevent damage to the thrust assembly. The
direction of rotation of the motor is correct when it coincides with the direction indicated by the arrow cast on the
pump body (counterclockwise when looking at the motor facing the shaft).
Start-up
6.6 Engine Considerations !
CAUTION
6.7 Other General Operating Considerations
DO NOT throttle the suction of the pump; throttling the suction of a centrifugal pump causes a reduction of the absolute
pressure at the impeller inlet. This is very harmful for the pump, since it causes erosion and premature destruction of its
components, product of the phenomenon called cavitation. Suction throttling is only allowed when the available NPSH of the
installation exceeds by a wide margin the NPSH required by the pump.
If the pump is jammed or turns with difficulty, the equipment must not be operated until the cause of the problem is located
and solved.
6.8 Rotation Management Control
Before final start-up, it is necessary to check the direction of rotation to ensure correct operation of the pump.
Correct direction of rotation
The motor cables are marked with the letters U-V-W, and should be connected to the corresponding U-V-W terminals on the
control panel. Identify and mark the power supply terminals R-S-T, using a cyclic phase detector with a clockwise rotating
indicator, and connect them to the R-S-T terminals on the control panel.
If you do not have a cyclic phase detector, precede as indicated. Connect the power supply cables to the control panel and to
the power supply circuit, just for a moment, and observe in which direction the motor-pump assembly tends to rotate. The
direction of rotation of the motor is correct when the assembly tends to rotate in the direction indicated by the arrow cast on
the pump. If the motor pump tends to rotate in the opposite direction to that indicated by the arrow, reverse the position of
any two power cables and you will obtain the correct direction of rotation.