Electrical Connection - Grundfos SE Service Instructions Manual

8. Electrical connection

EMC shielding of power and control cables must be connected and fixed by the operator.
DANGER
Electric shock
Death or serious personal injury
‐
Unauthorised people must not have any access to this product.
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 that it cannot be switched on
unintentionally.
WARNING
Electric shock
Death or serious personal injury
‐
Before installation and startup, check the power cable for damage.
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 ground complies
with the local regulations.
Connect the pump to an external main switch ensuring all-pole disconnection with a contact separation according to EN 60204-1,
5.3.2. 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 the local regulations.
Connect the pumps to a controller with a motor protection relay with IEC trip class 10 or 15 or NEMA-equivalent.
The power supply for the motor protection circuit must be low voltage, class 2.
If the power cable is damaged, it must be replaced by the manufacturer or his service agent.
Connect the pump to a motor-protective circuit breaker.
Set the motor-protective circuit breaker to the rated current of the pump, +10 % service factor for 50 Hz motors, +15 % service factor
for 60 Hz motors. The rated current is stated on the nameplate.
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.
The motor is effectively grounded with the power cable and pipes. The motor top cover is equipped with connections for external grounding or
an equipotential bonding conductor.
The most commonly used startup methods are the following:
• Direct-on-line starting (DOL).
• Star-delta starting (Y/D).
• Soft start.
The suitable starting method depends on several considerations on usage and mains 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 milliseconds, or according to the manufacturer's specifications.
The pump can be operated with a frequency converter according to the specifications of the manufacturer.
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