Electrical Connection; General; Motor Protection; Connection Of Motor - Grundfos SQ Installation And Operating Instructions Manual

4. Electrical connection

4.1 General

The electrical connection should be carried out by an
authorized electrician in accordance with local
regulations.
Before starting work on the pump,
make sure that the electricity supply
has been switched off and that it cannot
be accidentally switched on.
The pump must be earthed.
The pump must be connected to an
external mains switch with a minimum
contact gap of 3 mm in all poles.
If the motor cable is damaged, it must
be replaced by Grundfos, an authorised
Grundfos service workshop or similarly
qualified persons to avoid a hazard.
The supply voltage, rated maximum current and
power factor (PF) appear from the motor nameplate.
The required voltage for Grundfos submersible
motors, measured at the motor terminals, is
–10%/+6% of the nominal voltage during continuous
operation (including variation in the supply voltage
and losses in cables).
If the pump is connected to an electric installation
where an earth-leakage circuit breaker (ELCB) is
used as an additional protection, this circuit breaker
must trip out when earth fault currents with DC
content (pulsating DC) occur.
The earth leakage circuit breaker must be marked
with the following symbol:
Supply voltage:
1 x 200-240 V –10 %/+6 %, 50/60 Hz, PE.
The current consumption can only be measured by
means of a true RMS instrument. If other instruments
are used, the value measured will differ from the
actual value.
On SQ/SQE pumps, a leakage current of 2.5 mA at
230 V, 50 Hz, can typically be measured. The
leakage current is proportional to the supply voltage.
The SQE and SQE-NE pumps can be connected to a
control box, type CU 300 or CU 301.
Note: The pump must never be connected to a
capacitor or to another type of control box than
CU 300 or CU 301.
The pump must never be connected to an external
frequency converter.
.

4.2 Motor protection

The motor incorporates thermal overload protection
and requires no additional motor protection.

4.3 Connection of motor

The motor incorporates a starter device and can
therefore be connected directly to the mains.
Start/stop of the pump will typically be done via a
pressure switch, see fig. 3.
Note: The pressure switch must be rated for the
maximum amps of the specific pump size.
N L
P
Fig. 3

5. Installation

5.1 General
Before starting any work on the pump/
motor, make sure that the electricity
supply has been switched off and that it
cannot be accidentally switched on.
Note: Do not lower or lift the pump by means of the
motor cable.
The loose data plate supplied with the pump should
be fixed close to the installation site.

5.2 Assembly of pump part and motor

To assemble pump part and motor, proceed as folows:
1. Place the motor horizontally in a vice and tighten
it, see fig. 5.
2. Pull the pump shaft out to the position shown in
fig. 4.
Fig. 4
Pressure switch
9