Installation With External Coupling Device; Connection To The Power Supply And Determination Of The Sense Of Rotation; Installation Of Float Switches; Maintenance - Zenit DRO Manuel D'utilisation Et D'entretien

4.2.2 INSTALLATION WITH EXTERNAL COUPLING DEVICE

For fixed installations, motor pumps with a vertical outlet can be fitted with an external coupling device comprising
a fixed part, fitted to the outlet using either a standard DN 50 flange or BSP 2" thread, and a movable part which is
screwed onto the delivery pipeline (having first established the length). This device does not require any
anchorages at the bottom of the tank, and can therefore be fitted even when the tank is full.
Fig. 1/a illustrates the method of installation with external coupling device.

4.3 CONNECTION TO THE POWER SUPPLY AND DETERMINATION OF THE SENSE OF ROTATION

All operations connecting the motor pump to the electricity supply must be performed by specialised staff in full
compliance with current regulations.
WARNING: in the electrical connection phase connect the yellow-green earth cable first, then the other
connections, as indicated in chapter 8 "ELECTRICAL CONNECTIONS".
Check that the voltage and the frequency of the power supply are the same as those indicated on the motor pump
data plate and that the power absorbed by the motor pump is less than the maximum current available.
Before installation check that the power line is earthed and complies with current regulations and that the motor
pump cables are undamaged.
To protect the motor pump motor use an overload cutout suited to the electrical characteristics shown on the data
plate.
A diagram illustrating the correct supply of the motor pump is supplied in chapter 8 "ELECTRICAL
CONNECTIONS".
Before making the definitive connections of three phase motors the sense of rotation of the motor pump must be
determined.
To determine the sense of rotation proceed as follows:
- apply the provisions of paragraphs 1.2 and 1.3;
- lay the motor pump on one side in a horizontal position and leave unrestrained;
- connect the yellow-green earth lead and then the live leads temporarily to the solenoid switch;
- make certain there are no persons or objects within one metre of the motor pump;
- press the run button for a very brief period.
- look through the inlet hole and check that the rotor rotates anticlockwise.
If the direction of rotation is not correct, invert any two phase connections at the solenoid switch and try again.
Once the rotation is correct, MARK the connection sequence of the leads.
DEACTIVATE the temporary power connection and install the motor pump in its permanent position.

4.4 INSTALLATION OF FLOAT SWITCHES

If the motor pump is fitted with a float it operates completely automatically. Check that there are no objects which
could impede its movement. It is very important to fix float switches so that the cables cannot interfere with one
another, neither become twisted nor catch on projections inside the well. Float switches should be installed in such
a way that the minimum level is NEVER lower than the top cover of the motor pump. Float switches are best
secured to a rigid bracket mounted inside the well. Once the installation of the motor pumps, control panel and float
switches is completed, carry out a final inspection to check functional efficiency. Check with an ammeter that the
motor pump current is within the limits indicated on the data plate; also that the float switches cut in at the required
level.

5. MAINTENANCE

Before inspection and maintenance operations carefully read and apply the safety procedures indicated in
paragraphs 1.2 and 1.3
To ensure regular and long-lasting operation of the motor pump the user must perform regular inspections, periodic
maintenance and replacement of used parts. Monthly inspections are recommended, or every 500-600 working
hours.
- check that the supply voltage corresponds to the values indicated on the data plate;
- check that noise and vibrations are at their original levels;
- for three phase motors, use
balanced and do not exceed the values shown on the rating plate.
An exploded view of the motor pump is shown in fig. 2 - 2/a.

5.1 CHECKING AND CHANGING THE OIL IN THE MECHANICAL SEAL CHAMBER

Before inspection and maintenance operations carefully read and apply the safety procedures indicated in
paragraphs 1.2 and 1.3
The oil should be changed every 5000-7000 working hours, or at least once a year.
Proceed as follows:
Position the motor pump horizontally.
- Unscrew the plug and drain off the oil into a suitable container, or use an oil aspiration device.
- If the oil is clean, then the mechanical seal is still in good condition and the chamber can be refilled with fresh
oil.
amperimetric pincers to check the absorbances on the three phases are
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