Electrical Connection; Frequency Converter - Grundfos SL1 Notice D'installation Et De Fonctionnement

9. 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 National
Electrical Code and all local codes.
It must be possible to lock the mains switch in
position 0. Type and requirements as specified in
National Electrical Code and all local codes.
The electrical connection must be carried out in
accordance with local regulations.
Warning
The pumps must be connected to a controller
with a motor protection relay with IEC trip class
10 or 15 or nema equivalent.
Warning
Power supply for motor protection circuit must
be low voltage, Class 2.
See motor protection wiring diagram in section
9.1 Wiring diagrams.
Warning
FM
Pumps for hazardous locations must be
connected to a controller with a motor protection
relay with IEC trip class 10.
See fig. 12.
Warning
FM
Do not install Grundfos 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 lead 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 earth lead must be minimum AWG 12 type
RHH, RHW, RHW-2 or similar, rated for 600 V and
min. 194 °F (90 °C), 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 Dedicated Controls, DC/DCD or the
SLC/DLC controllers, via an intrinsically safe
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 current of the pump +15 % Service factor.
Caution
The rated current is stated on the pump
nameplate.
If the pump has an FM mark on the nameplate,
make sure that the pump is connected in
Caution
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.
Pumps without sensor must be connected to one of these two
controller types:
• a Grundfos DC, DCD pump controller
• a Simplex (SLC) or Duplex (DLC) pump controller.
Pumps with sensor must be connected to a Grundfos IO 113
and the following controller type is recommended:
• a Grundfos DC, DCD pump controller.
Warning
FM
Before installation and the first start-up 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
Caution
be 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.

9.7 Frequency converter

13