6.7 Electrical and variable-frequency
drive information
WARNING
USA: All electrical work must be
performed by a qualified electrician
and installed in accordance with the
National Electrical Code, local codes
and regulations.
WARNING
Canada: All electrical work must be
performed by a qualified electrician
and installed in accordance with the
Canadian Electrical Code, local codes
and regulations.
WARNING
Provide acceptable grounding in
order to reduce the risk of electric
shock during operation of this pump.
If the means of connection to the box
connected to the power supply is
other than a grounded metal conduit,
ground the pump by connecting a
copper conductor, at least the size of
the circuit supplying the pump, to the
grounding screw provided within the
terminal box.
Make sure that the voltage, phase number and
frequency of the power supply match those of
the motor. Motor voltage, phase number,
frequency and full-load current information can
be found on the nameplate attached to the
motor.
Motor electrical data can be found in section
10.6.1 Grundfos submersible motors, 60
WARNING
If voltage variations are larger than
± 10 %, do not operate the pump.
Direct-on-line starting is used due to the
extremely short run-up time of the motor
(maximum 0.1 second), and the low moment of
inertia of the pump and motor. Direct-on-line
starting current (locked rotor current) is between
4 and 6.5 times the full-load current.
If direct-on-line starting is not acceptable and
reduced starting current is required, use an
autotransformer or resistant starters for 5 to 30
hp motors, depending on the cable length. For
motors over 30 hp, use autotransformer starters.
14
Hz.