2.
OPERATION
IOM manual CTI & CTH centrifugal pumps
13
2.
OPERATION
2.1.
Start-up
Check manually that the motor is free to turn, moving the motor cooling fan.
Make sure that the piping is not clogged and is free from residues or foreign objects.
Make sure that the liquid flows regularly into the pump.
The pump and piping connected to it, at least the suction pipe, must be full of liquid.
Any air or gas must be carefully released. In case of suction with negative head, fill the
suction piping and check how the bottom valve works. It must guarantee that the liquid
must not flow back, emptying therefore the suction pipe with consequent disconnection
of the pump.
The suction shut-off valve (if any) must be completely open.
The shut-off / regulation valve on the discharge side must be completely closed.
The motor must turn in the same direction as the arrow shown on the pump. The
direction of rotation is always clockwise looking at the pump from the motor side; check
by starting briefly, then looking at the direction of rotation of the motor fan through the
fan lid. If it is wrong, the motor must be stopped immediately. Change the connection
to the terminals of the electric motor (chapter 1.10 “Motor connection”) and repeat the
procedure described above.
Any auxiliary connections must all be connected.
If the pump is equipped with an oil reservoir, make sure to fill it before start-up.
2.1.1.
Starting the pump
Start the electric motor and open the discharge shut-off / regulation valve gradually until the
desired output has been reached. The pump must not run two or three minutes with closed
discharge. Longer operation in these conditions can seriously damage the pump.
If the pressure shown on the pressure gauge on the discharge piping does not increase, turn
off the pump immediately and release pressure carefully. Repeat the connection procedure.
If there are changes of flow rate, head, density, temperature or viscosity of the liquid, stop
the pump and get in touch with our technical service.
2.1.2.
Restarting after power shut-off
In case of accidental stopping, make sure that the non-return valve has prevented backflow
and check that the motor cooling fan has stopped. Start the pump again following the
instructions of chapter 2.1.1 ”Starting the pump”.
If the pump intakes from a lower level than it is positioned, it can un-prime during the
standstill and therefore you must check again before starting that the pump and the suction
piping are full of liquid.
