Electrical Connection; Checking The Direction Of Rotation - Grundfos Unilift AP35B Installation And Operating Instructions Manual

3.3 Electrical connection

DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before
starting any work on the product.
- Make sure that the power supply cannot
be accidentally switched on.
DANGER
Electric shock
Death or serious personal injury
- The installation must be fitted with a
residual current device (RCD) with a
tripping current less than 30 mA.
DANGER
Electric shock
Death or serious personal injury
- Make sure that the power supply plug
delivered with the product is in
compliance with local regulations.
- The plug must have the same protective
earth (PE) connection system as the
power outlet. If not, use a suitable
adapter if allowed by local regulations.
DANGER
Electric shock
Death or serious personal injury
- Power cables without a plug must be
connected to a supply disconnecting
device incorporated in the fixed wiring
according to the local wiring rules.
All electrical connections must be carried
out by a qualified person in accordance
with local regulations.
Depending on local regulations, a pump
with minimum 10 m of mains cable must
be used if the pump is used as a portable
pump for different applications.
Make sure that the product is suitable for the supply
voltage and frequency available at the installation
site. Voltage and frequency are marked on the pump
nameplate.
The pump must be connected to an external main
switch. If the pump is not installed close to the
switch, the switch must be of a lockable type.
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.
If the motor is overloaded, it will stop
automatically. When the motor has cooled
to normal temperature, it restarts
automatically.

3.4 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 largest quantity of water indicates the correct
direction of rotation.
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