Installation Of Float Switches; Maintenance; Checking And Changing The Oil In The Mechanical Seal Chamber; Checking Parts Subject To Wear - Zenit DRF 75/2/G32V A0CM-EX Manuel D'utilisation Et D'entretien

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
WARNING: the explosion proof layer and cable clamps of any explosion proof motor pump must not be interfered with.
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 amperimetric pincers to check the absorbances on the three phases are 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 - 2/b - 2/c - 2/d - 2/e - 2/f - 2/g - 2/h on page 73-74-75-76-77-78-79-80-81.

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.
- If a very small quantity of water is detected at the bottom of the mechanical seal chamber, this will be due to condensation and is normal, not a
sign of any fault with the mechanical seal.
- If a substantial quantity of water has entered the oil chamber and contaminated the oil, this indicates that the mechanical seal needs inspecting,
and perhaps replacing
- Fill the chamber completely with biodegradable oil, CASTROL HYDROIL P46 or similar, and once full remove 20-25 cc to ensure a sufficient air
cushion in the chamber;
- When finished tighten the plug and re-install the motor pump.
If none of the above is available, exceptionally, common vaseline oil can be used. For maintenance, contact our nearest service centre.
Any repairs to the motor pump must be carried out by the manufacturer or by specialist personnel. If this is not respected, the guarantee will be
invalidated and the machine may become unsafe.

5.2 CHECKING PARTS SUBJECT TO WEAR

Before inspection and maintenance operations carefully read and apply the safety procedures indicated in paragraphs 1.2 and 1.3
During programmed maintenance or at any time in which the performance of the motor pump should be reduced or if vibrations and noise
should increase, the hydraulic parts subject to wear must be checked. Original spare parts only should be used. If the hydraulic part should be
partially or totally blocked it should be cleaned thoroughly with a jet of high pressure water. If necessary dismantle the hydraulic part referring to the
exploded view in fig. 2 - 2/a - 2/b - 2/c - 2/d - 2/e - 2/f - 2/g - 2/h on page 73-74-75-76-77-78-79-80-81.

6. MINOR PROBLEMS: CAUSES AND SOLUTIONS

FAULTS
motor does not turn
motor functions normally but no water
is pumped
pump has reduced flow rate
thermal protector has cut in
POSSIBLE CAUSE
no voltage
automatic switch tripped
impeller jammed
thermal protection cut in
check valve jammed
blocked pipeline
impeller, valve or pipelines obstructed
liquid level too low
incorrect supply voltage
wrong direction of rotation (three phase motor)
impeller jammed
temperature of liquid too high
check the power supply line
reset the switch and establish the cause
establish the cause of the trouble and remove it
resets automatically (not on -EX versions)
clean the valve and check its operation
identify the obstruction and remove it
identify the obstruction and remove it
turn the pump off immediately
match the voltage to the values indicated on the
data plate
invert any two phases
identify the cause of the trouble and remove it
contact your nearest zenit dealer
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SOLUTION