Electrical Connection - Grundfos SL1 Serie Montage- Und Betriebsanleitung

8. Electrical connection

Warning
The pump must not run dry.
An additional level switch must be installed to ensure
that the pump is stopped in case the stop level switch
is not operating.
Warning
Connect the pump to an external mains switch which
ensures all-pole disconnection with a contact
separation according to EN 60204-1, 5.3.2.
It must be possible to lock the mains switch in
position 0. Type and requirements as specified in EN
60204-1, 5.3.2.
The electrical connection must be carried out in
accordance with local regulations.
Warning
The pumps must be connected to a control box with
a motor protection relay with IEC trip class 10 or 15.
Warning
Power supply for motor protection circuit must be low
voltage, Class 2.
See motor protection wiring diagram in section
8.1 Wiring diagrams.
Warning
Pumps for hazardous locations must be connected to
a control box with a motor protection relay with IEC
trip class 10.
Warning
Do not install Grundfos control boxes, pump
controllers, Ex barriers and the free end of the power
cable in potentially explosive environments.
The classification of the installation site must be
approved by the local fire-fighting authorities in each
individual case.
On explosion-proof pumps, make sure that an
external earth conductor is connected to the external
earth terminal on the pump using a secure cable
clamp. Clean the surface of the external earth
connection and mount the cable clamp.
The cross section of the earth conductor must be at
2
least 4 mm , e.g. type H07 V2-K (PVT 90 °) yellow/
green.
Make sure that the earth connection is protected
from corrosion.
Make sure that all protective equipment has been
connected correctly.
Float switches used in potentially explosive
environments must be approved for this application.
They must be connected to the Grundfos LC, LCD
108 pump controller via the intrinsically safe LC-Ex4
barrier to ensure a safe circuit.
Warning
If the supply cable is damaged, it must be replaced
by the manufacturer, its service agent or similarly
qualified persons.
Set the motor-protective circuit breaker to the rated
Caution
current of the pump. The rated current is stated on
the pump nameplate.
If the pump has an Ex mark on the nameplate, make
Caution
sure that the pump is connected in accordance with
the instructions given in this booklet.
The mains supply voltage and frequency are marked on the pump
nameplate. The voltage tolerance must be within - 10 %/+ 10 % of
the rated voltage. Make sure that the motor is suitable for the
power supply available at the installation site.
12
All pumps are supplied with 10 m cable and a free cable end,
except for pumps for Australia which have 15 m cable.
Pumps without sensor must be connected to one of these three
controller types:
• a control box with motor-protective circuit breaker, such as a
Grundfos CU 100
• a Grundfos LC, LCD 107, LC, LCD 108 or LC, LCD 110 pump
controller
• a Grundfos DC, DCD pump controller.
Pumps with sensor must be connected to a Grundfos IO 113
and one of these three controller types:
• a control box with motor-protective circuit breaker, such as a
Grundfos CU 100
• a Grundfos LC, LCD 107, LC, LCD 108 or LC, LCD 110 pump
controller
• a Grundfos DC and DCD pump controller.
Warning
Before installation and the first startup of the pump,
check the condition of the cable visually to avoid
short circuits.
Pumps with WIO sensor
For safe installation and operation of pumps equipped with a
WIO sensor, we recommend to install an RC filter between the
power contactor and the pump.
If an RC filter is installed to avoid any kind of
transients in the installation, the RC filter must be
Caution
installed between the power contactor and the pump.
Please note that the following aspects may cause problems in
case of transients in the power supply system:
• Motor power:
– The bigger the motor, the higher the transients.
• Length of motor cable:
– Where power and signal conductors are running in parallel
close to each other, the risk of transients causing
interference between power and signal conductors will
increase with the length of the cable.
• Switchboard layout:
– Power and signal conductors must be physically separated
as much as possible. Close installation can cause
interference in case of transients.
• Supply network "stiffness":
– If a transformer station is located close to the installation,
the supply network may be "stiff" and transient levels will be
higher.
If combinations of the above aspects are present, it may be
necessary to install RC filters for pumps with WIO sensors to
protect against transients.
Transients can be completely eliminated if soft starters are used.
But be aware that soft starters and variable speed drives have
other EMC-related issues that must be taken into consideration.
For more information, see section
operation
8.7 Frequency converter