English (GB)
11
Fig. 3
To ensure sufficient cooling of the motor, it is
important to observe the maximum liquid
temperature of 35 °C under all conditions.
The motor should always be installed above the well
screen. If a flow sleeve is used, the pump may be
installed freely in the borehole.
If the actual temperature of the pumped liquid
exceeds the specified value or the operating
conditions otherwise fall outside the specified
conditions, the pump may stop. Please contact
Grundfos.
5. Electrical connection
5.1 General
The electrical connection should be carried out by an
authorised electrician in accordance with local
regulations.
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.
TM0
1
051
8
1
2
9
7
Caution
The borehole diameter must be at least
76 mm (approx. 3").
Caution
Do not let the pump run against a
closed discharge pipe for more than
5 minutes. When the discharge pipe is
closed, there is no cooling flow and
there is a risk of overtemperature in
motor and pump.
Liquid
temperature
Borehole
diameter
Pump
diameter
Warning
Before starting work on the pump,
make sure that the power 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.
Caution
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.
