Safety; Electrical Connection; Checking Of Direction Of Rotation; Installation - Grundfos Unilift AP35B Installations- Und Bedienanleitung

2. Safety

Pump installation in wells must be carried
out by specially trained persons.

3. Electrical connection

Note: Depending on local regulations, a pump with
10 metres of mains cable must be used if the pump
is used as a portable pump for different applications.
The electrical connection should be carried out in ac-
cordance with local regulations.
The operating voltage and frequency are marked on
the pump nameplate. Please make sure that the mo-
tor is suitable for the electricity supply on which it will
be used.
As a precaution, the pump must be con-
nected to a socket with earth connection.
The installation must be fitted with an
earth leakage circuit breaker (ELCB) with
a tripping current < 30 mA.
The pump must be connected to an exter-
nal mains switch with a minimum contact
gap of 3 mm in all poles. If the pump is not
installed close to the switch, this must be
of a lockable type.
Three-phase pumps must be connected to an exter-
nal motor starter with differential release. The nomi-
nal current of the motor starter must correspond to
the electrical data marked on the pump nameplate.
If a level switch is connected to a three-phase pump,
the motor starter must be magnetically operated.
Single-phase pumps incorporate thermal overload
protection and require no additional motor protec-
tion.
Note: If the motor is overloaded, it will stop automat-
ically. When it has cooled to normal temperature, it
will restart automatically.

3.1 Checking of direction of rotation

(Three-phase pumps only)
The direction of rotation should be checked every
time the pump is connected to a new installation.
Check the direction of rotation as follows:
1. Position the pump so that the impeller can be ob-
served.
2. Start the pump for a short period.
3. Observe the rotation of the impeller. The correct
direction of rotation is indicated by an arrow on
the top of the motor (clockwise when seen from
the bottom). If the impeller rotates in the wrong
direction, reverse the direction of rotation by in-
terchanging two of the phases to the motor.
If the pump is connected to a piping system, the di-
rection of rotation can be checked as follows:
1. Start the pump and check the quantity of water or
the discharge pressure.
2. Stop the pump and interchange two of the
phases to the motor.
3. Start the pump and check the quantity of water or
the discharge pressure.
4. Stop the pump.
5. Compare the results taken under points 1 and 3.
The connection which gives the larger quantity of
water or the higher pressure is the correct direc-
tion of rotation.

4. Installation

The installation of the pump must be car-
ried out by specially trained persons.
Care must be taken to ensure that persons
cannot come into contact with the pump
impeller.

4.1 Connection

For permanent installation, it is recommended to fit a
union, a non-return valve and an isolating valve in
the discharge pipe.
If the pump is installed in a pit with a minimum free
cable length of 100 mm, see fig. 5, the minimum pit
dimensions must be as shown in fig. 2.
Furthermore, the pit should be dimensioned accord-
ing to the relation between the water flow to the pit
and the pump performance.
Fig. 2
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550 mm

4.2 Pump location

The pump can be used in vertical or horizontal posi-
tion, see fig. 3.
During continuous operation, the motor and the
pump inlet must always be completely covered by
the pumped liquid.
Fig. 3
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