5, Electrical Connection; Starting; Stopping; Periodical Checks And Maintenance - Calpeda N Serie Instrucciones Originales De Uso

between pump casing feet and baseplate.
First tighten the screws joining the foot and the
base and then, the screw between the foot and the
support. In this way, alignment will not be altered by
the support foot.
After alignment procedure, before star-
ting the pump attatch the coupling guard
(safety protection against accidental con-
tact).
5. Electrical connection
Electrical connection must be carried
out only by a qualified electrician in
accordance with local regulations.
Follow all safety standards.
The unit must be properly earthed (grounded).
Compare the frequency and mains voltage with the
name-plate data and connect the supply conduc-
tors to the terminals in accordance with the name-
plate specifications and the operating instructions
(if available) of the motor.
With motor power rating ≥ 5,5 kW, avoid direct
starting. Provide a control panel with star-
delta starting or an other starting device.
Install a device for disconnection from the mains
(switch) with a contact separation of at least 3 mm
on all poles.
Install an overload protection device appropriate
for the rated current of the pump.

6. Starting

ATTENTION: never run the pump dry - not
even for a short trial run.
Start the pump after filling it completely with liquid.
When the pump is located above the water
level (suction lift operation, fig. 4) or with a positi-
ve suction head which is too low (less than 1 m)
to open the non-return valve, fill the suction pipe
and the pump through the priming hole (fig. 8).
Replace threaded plug after each operation.
Fig. 8 Filling.
When the liquid level on the suction side is
above the pump (inflow under positive suction
head), fill the pump by opening the suction gate
12
valve slowly and completely, keeping the delivery
gate valve open to release the air.
Close the delivery gate valve completely, and check
the pressure of the suction head to make sure the
maximum final pressure does not then exceed 10 bar.
Start the pump with the delivery gate valve clo-
sed. Then slowly open the discharge gate valve and
proceed to regulate the pump duty point within the
limits indicated on the nameplate.
Never run the pump for more than five
minutes with a closed gate valve.
Make sure the direction of rotation is as shown by
the arrow on the pump casing. If rotation is in the
opposite direction disconnect electrical power and
reverse the connections of two phases.

6.1. Stopping

Close the delivery gate valve if a check valve is
not fitted.
Close the suction gate valve if a foot valve is not fitted.
Switch off the motor.

7. Periodical checks and maintenance

Make sure the pump operates in conformity with
the range of specified levels of performance and
that absorbed current indicated on the nameplate
is not exceeded.
Check the alignment of the coupling (see section 4.).

7.1. Pumps with mechanical seal

Mechanical seals do not require maintenance.
Except for possible initial leakage after the first
start-up, the mechanical seal on the shaft must
function without any loss of liquid.
Do not run the pump when dry.
When a leak occurs and gradually increases, the
seal must be replaced.
Replacing the mechanical seal (see section 8).
Make sure that the spring of the new seal has a
clockwise winding (when viewing the seal from
the stationary part) to conform with the direction
of rotation of the shaft.
Make sure that all the parts which the seal comes
into contact with are clean and that there are no
cutting edges or burr on the chamfered edges
where the elastic seal rings are fitted in the sea-
ting of the fixed part and on the shaft or shaft
sleeve.
ATTENTION: never allow seal rings in EPDM
(Ethylene-Propylene-Diene Monomer) to come
into contact with oil or grease. To make
assembly easier, lubricate the seatings and seal
4.93.141 rings with water or other liquids compatible with
the material in which the seal rings are made.
Care must be taken to avoid damaging the seal
surfaces by impact.