SAER Elettropompe CL95 Serie Manuel D'utilisation Et D'entretien page 38

"IN TUBE" INSTALLATION
It is possible to use suction shells, pressure or cooling according to the schemes of Fig. 4
In the case of installation horizontally or inclined, follow the directions above.
PLANTS THAT ARE SUBJECT TO A RISK OF WATER HAMMER
The water hammer is a hydraulic phenomenon that occurs when a fluid, inside a conduit, undergoes a strong variation in speed (for ex-
ample as a result of sudden closure or opening of a valve).
The occurrence of water hammer causes a strong System overpressure which can severely damage the equipment (pump, motor,
valves, pipes, etc. ..).
Main precautions to be taken to avoid the water hammer:
- Avoid sudden and rapid maneuvers;
- Adopting progressive start and stop systems;
- Install a check valve directly at the pump outlet;
- Install vents that allow the removal of pressurized air bags at the appropriate positions;
- Install pressure relief valve (s);
- Install an upstream pressure relief surge anticipating control valve);
- Install expansion crates (tanks) when needed.
CONNECTION TO THE POWER SUPPLY
In order to work, the motor must be connected to an electrical control panel.
Use control panels according to CEI EN 60204-1 and to the National standards of the place where it is installed.
The control panel must also be provided with all the protections necessary to prevent failure or malfunction of the
power supply (voltage fluctuations, lack of phase, etc. ...) or overload can cause damage to the engine: see para-
WARNING! graph "Checks on the
electrical system".
The use of a control panel that is not suitable voids the warranty on the motor.
WARNING! Set properly the values of the electrical devices (protections, electronic devices etc...)
The connection to the power grid must be done in the respect of the local and national standards of the electric
system of the place where the pump is installed.
Furthermore, respect the connection diagrams supplied with the motor and with the control panel.
Perform the earth connection before all the other connections.
Verify the correct operation of the electric equipment (control panel etc...)
TYPES OF STARTING ALLOWED
WARNING! The group must not be started under full load. Refer to paragraph 6 for the starting procedure.
DIRECT STARTING (DOL)
Any motor can be started directly. This type of starting has the following disadvantages:
the starting current reaches very high values (refer to the technical documentation, catalogs and sheets for the starting current
•
values).
the stress on mechanical components of pump, motor and installation, is greater than that caused by progressive starters.
•
the direct starting of the group can cause a voltage drop along the power line.
•
For this reason in recommended only for small power motors (indicatively up to 37 kW)
Set the security value of the current 5% in most of the absorbed current value at the operating point (in any case this value must not
exceed more than 5% of the rated current of the motor nameplate).
PROGRESSIVE STARTERS
STARTING STAR / DELTA (Y / D)
Recommended for motors with a power not exceeding 110 kW. The motors for Y / D starting, so with 6 output cables are available on
request.
The maximum duration of the starting time (Y-operation) must not exceed 2.5 s and the time of commutation from
WARNING!
star (Y) to delta (D) must not exceed 60 ms.
If the protection on the current is on the line, set the security value of the current 0.58 x value of current absorbed in the duty point.
If the protection on current is not installed on the line, set the security value on the current 5% in most of the absorbed current value to
the duty point (in
each case, the set value must not exceed more than 5% of the rated current the motor nameplate).
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- Translation of the original instructions