Electrical And Variable-Frequency Drive Information - Grundfos SP Series Installation And Operating Instructions Manual

6.7 Electrical and variable-frequency drive information

DANGER
Electric shock
Death or serious personal injury
‐
Switch off the power supply before starting any work
on the product.
‐
Make sure that the power supply cannot be
accidentally switched on.
USA and Canada: All electrical work must be performed
by a qualified electrician and installed in accordance with
the National Electrical Code/Canadian Electrical Code,
local codes and regulations.
DANGER
Electric shock
Death or serious personal injury
‐
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 the motor. Motor voltage, phase number,
frequency and full-load current information can be found on the
motor nameplate.
The equipment-grounding lead, when one is provided, is the
conductor that has an outer surface of insulation that is green with
or without one or more yellow stripes.
If voltage variations are larger than
± 10 %, do not operate the pump.
Direct-on-line (DOL) 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. DOL starting current (locked rotor
current) is between 4 and 6.5 times the full-load current.
If DOL 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.
Related information
10.6.1 Grundfos submersible motors, 60 Hz
6.7.1 Engine-driven generators
If the pump is operated by an engine driven generator, contact the
manufacturer of the generator to ensure the proper generator is
selected and used. See sectionGuide for engine-driven generators
in submersible pump applications for generator sizing guide for
generator sizing guide.
If power is supplied through transformers, section Transformer
capacity required for three-phase submersible motors outlines the
minimum KVA rating and capacity required for satisfactory pump
operation.
Related information
10.2 Guide for engine-driven generators in submersible pump
applications
10.3 Transformer capacity required for three-phase submersible
motors
6.7.2 Control box or panel wiring
Single-phase motors
Connect single-phase motors as indicated in the motor control box.
A typical single-phase wiring diagram using a Grundfos control box
is indicated in the figure below.
Motor burnout protection through CUE, CU331SP, or MP
204.
Use approved dry-run protectio0n, such as MP 204.
9
1
3 4 5 6
Single-phase wiring diagram for Grundfos control boxes
Pos. Description
1 Control box
2 Fused disconnect switch
3 Red
4 Green
5 Yellow
6 Black
7 Use dotted line for 115 V operation
8 Well seal
9 Pressure switch
2
7
8
15