Zenit Grey Serie Installation Und Betrieb Seite 30

Safety, Installation and Operations Manual - Original instructions
3. INSTALLATION
3.1 General safety precautions
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Fence off the working area by appropriate means and wear personal protection equipment.
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Before carrying out any operation, make sure that the pump and electrical panel are disconnected from the electrical mains and cannot be
accidentally powered up.
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Check the electric cable and gaskets for damage and make sure that the impeller turns freely.
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The size of the tank in which the pump is installed must be such that:
- any level float switches are able to move freely;
- the number of pump switch on/switch off cycles does not exceed the permitted number stated in the technical information;
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The pump must be lowered into the tank using a sling or chain of suitable size tied to the handle.
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Prior to installation, make sure the tank bottom is even.
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To prevent the cavitation problems caused if the pump draws in air, ensure that the liquids do not flow into the tank near to or towards the pump.
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Make sure that the pump does not operate off its characteristic curve.
Make sure that the atmosphere in the working area is not potentially explosive.
Persons must not enter the installation area when the atmosphere is explosive.
The classification of the installation site must be approved by the local fire-fighting
autorities in each individual case.
EN
The shock from built up electrostatic charges on isolated components could cause
an explosion. -Ex pumps do not have isolated components that are electrostatically
chargeable and they are all equipped with screw for connection to the equipotential
ground network (Fig. 9). Any additional components installed in the hazardous area
must be connected to the earthing network according to the EN 1127-1 rule.
Check the suitability for use in potentially explosive atmospheres of each additional
component installed in the hazardous area.
Prior to installation, check the oil level in the mechanical seals oil chamber.
3.2 Checking the impeller rotation direction
Before making the definitive electrical connection, a skilled technician must make sure the impeller rotation direction is correct.
The pump carries a decal which indicates the correct impeller rotation direction (green arrow) and the relative kickback direction (red arrow) when
the pump is viewed from above (Fig. 5).
All of the following operations should be carried out in a secure place, in absence of potentially explosive atmospheres;
Proceed as follows:
1. Place the pump vertical on its feet or base.
2. Secure the pump by tying a suitably sized chain or sling to the handle on the top to prevent it from falling over after the kickback.
CAUTION
The kickback may be very strong. Do not stand close to the pump during the procedure.
3. Temporarily connect the yellow-green wire to the system ground connector and then connect the power supply wires to the contactor.
4. Make sure there are no people or objects within a distance of at least 2 metres of the pump.
5. Operate the start switch, power up the pump for a few seconds and then shut off the power by flicking the stop switch.
6. Check that the rotation direction is correct.
If the pump is rotating in the wrong direction, invert two of the pump's three power supply phases and try again, repeating the procedure described.
Once the connection which provides the correct rotation direction has been obtained, MARK the precise order in which the wires have been con-
nected to the system, DISCONNECT the power supply wires from the pump and proceed with definitive installation.
CAUTION
If more than one pump is connected to a single control panel, the rotation direction must be checked individually for each
unit installed.
3.3 Installing the float switch control system
Float switches allow one or more pumps to be started and stopped in response to the level of liquid in the tank.
They can also be connected to alarm devices to prevent operational problems (overflow or unexpected dry
running) (Fig. 10).
They must be installed well away from turbulence or inflows of water.
In the event of strong turbulence, float switches should be installed on a rigid rod mounted inside the pit.
Make sure that there are no items which may obstruct movement of the floats and that the wires do not inter-
fere with each other, and cannot become tangled or trapped on projections inside the tank.
Float switches must be installed in such a way that the correct minimum liquid level is guaranteed.
The user must ensure that the pump operates always with the minimum level of pumped liquid
controlled by two level sensors (in redondancy) to shut down the power supply when the liquid
to be pumped belows the minimum level.
Only use level sensor according with the -Ex classification of the installation site.
The connection to the electric control panel must be carried out using an Intrinsic Safe Circuit
such as a Zener safety barrier or a galvanic isolation barrier.
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better together
9
ON
OFF
10