Electrical Connection - Grundfos SE Serie Notice D'installation Et De Fonctionnement

7. Electrical connection

DANGER
Electric shock
Death or serious personal injury
‐
Before starting any work on the product, make sure
that the power supply is switched off and it cannot be
switched on unintentionally.
DANGER
Electric shock
Death or serious personal injury
‐
The pump must be grounded.
‐
Before connecting the pump to the voltage supply,
make sure the connection to the ground complies with
local regulations.
Connect the pump to an external main switch ensuring all-
pole disconnection with a contact separation according to
National Electrical Code (NEC) and all local codes. It must
be possible to lock the main switch in position 0.
The supply voltage and frequency are marked on the
nameplate. Make sure that the motor is suitable for the
power supply at the installation site.
The electrical connection must comply with local
regulations.
Connect the pump to a controller with a motor protection
relay with IEC trip class 10 or 15 or NEMA equivalent.
Power supply for the motor protection circuit must be low
voltage, Class 2.
Connect pumps installed in hazardous locations to a
control box with a motor protection relay with an IEC trip
class 10.
• Do not install pump controllers, Ex barriers or 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.
• On explosion-proof pumps, make sure that an external
ground conductor is connected to the external ground
terminal on the pump by a secure cable clamp. Clean
the surface of the external ground conductor and
mount the cable clamp.
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• The ground conductor must be minimum AWG 12 type
RHH, RHW, RHW-2 or similar, rated for 600 V and
minimum 194 °F (90 °C), yellow and green.
• Make sure that the ground conductor is protected from
corrosion.
• Make sure that all protective equipment is 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 with an
intrinsically safe barrier to ensure a safe circuit.
If the supply cable is damaged, it must be replaced by the
manufacturer or its service agent.
Connect the pump to a motor-protective circuit breaker.
Set the motor-protective circuit breaker to the rated
current of the pump + 15 % service factor. The rated
current is stated on the nameplate.
If the pump has an FM mark on the nameplate, make sure
that it is connected in accordance with the instructions of
this manual.
The supply voltage and frequency are marked on the nameplate.
The voltage tolerance at the motor terminals must be within ± 10 %
of the rated voltage.
Make sure that the motor is suitable for the power supply available
at the installation site.
The motor is grounded through the power cable and the pipes. The
motor top cover is equipped with connections for external grounding
or an equipotential bonding conductor.
Maintenance and service work on explosion-proof pumps
FM
must be carried out by Grundfos or an authorized service
workshop.
Before installation and the first startup of the pump, check
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the condition of the cable to avoid short circuits.
The most commonly used startup methods are the following:
• direct-on-line (DOL) start.
• star-delta (Y/D) start.
• soft start.
The starting method depends on several considerations on usage
and main supply conditions.
When using star-delta start, it is important to keep
switching transient time to a minimum to avoid high
transient torques. Use a time relay with a switching time of
maximum 50 minutes or according to the specifications of
the manufacturer.
The pump can be operated by a frequency converter according to
the specifications of the manufacturer.
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