Checking The Impeller Rotation Direction; Installing The Float Switch Control System - Zenit Grey Serie Manual De Primera Instalación

First installation manual – Translation of original instructions

2.4 Checking the impeller rotation direction

Before making the definitive electrical connection, a skilled technician must make sure the impeller rotation direction is correct.
The three-phase 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. 2).
All of the following operations must be carried out in safety area, in absence of potentially explosive atmospheres.
Proceed as follows:
1. Take the precautions detailed in the "Safety Precautions" manual.
2. Place the pump vertical on its feet or base.
3. 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.
warning!
The kickback may be very strong. Do not stand close to the pump during the procedure.
4. Temporarily connect the yellow-green wire to the system ground connector and then connect the power supply wires to the contactor.
5. Make sure there are no people or objects within a distance of at least 2 metres of the pump.
6. Operate the start switch, power up the pump for a few seconds and then shut off the power by flicking the stop switch.
7. Check that the rotation direction is correct.
EN
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.
warning!
If more than one pump is connected to a single control panel, the rotation direction must be checked individually for each
unit installed.

2.5 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 dry running) (Fig. 5).
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 interfere
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 minimum liquid level must be controlled by two float switch (in redondancy) to shut down
the power supply when the liquid to be pumped belows the minimum level (pump fully submer-
ged).
Only use float switch sensor according with the 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.
Ensure that the switch from shut down to start-up occurs only and exclusively if all the floats find themselves
in the position shown in Fig 6.
Ensure that the switch from start-up to shut down occurs only and exclusively if both of the floats find themsel-
ves in the position shown in Fig 7.
Make sure that effective volume of the tank does not become so low that the number of starts per hour exceeds the maximum admitted.
20
ON
Fig. 6
OFF
Fig. 7
Grey
better together
ON
OFF
Fig. 5