Grundfos UNILIFT AP35B, Installation And Operating Instructions Manual

Page: 7 / 204

English (GB)
7
3. Electrical connection
The electrical connection must be carried out in
accordance with local regulations.
The operating voltage and frequency are marked on
the pump nameplate. Make sure that the motor is
suitable for the power supply on which it will be used.
Three-phase pumps must be connected to an
external motor-protective circuit breaker with
differential release. The rated current of the motor-
protective circuit breaker must correspond to the
electrical data marked on the pump nameplate.
If a level switch is connected to a three-phase pump,
the motor-protective circuit breaker must be
magnetically operated.
Single-phase pumps incorporate thermal overload
protection and require no additional motor
protection.
3.1 Checking the direction of rotation
Three-phase pumps only
Check the direction of rotation every time the pump
is connected to a new installation.
1. Position the pump so that you can observe the
impeller.
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
interchanging two of the phases to the motor.
If the pump is connected to a pipe system, check the
direction of rotation in this way:
1. Start the pump and check the quantity of water or
the 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 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
direction of rotation.
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.
Warning
As a precaution, the pump must be
connected to a socket with earth
connection. The installation must be fitted
with an earth leakage circuit breaker
(ELCB) with a tripping current less then 30
mA.
The pump must be connected to an
external mains switch with a minimum
contact gap of 3 mm in all poles. If the
pump is not installed close to the switch,
the switch must be of a lockable type.
Warning
The protective earth of the socket outlet
must be connected to the protective earth
of the pump. The plug must therefore have
the same PE connection system as that of
the socket outlet. If not, use a suitable
adapter.
Note
If the motor is overloaded, it will stop
automatically. When the motor has cooled
to normal temperature, it restarts
automatically.