Electrical - Grundfos SP Series Installation And Operating Instructions Manual

Warning
Important: Plastic and flexible pipe
tend to stretch under load. This
stretching must be taken into
account when securing the cable to
the riser pipe. Leave 3 to 4 inches of
slack between clips or taped points
to allow for this stretching. This
tendency for plastic and flexible pipe
to stretch will also affect the
Note
calculation of the pump setting
depth. As a general rule, you can
estimate that plastic pipe will stretch
to approximately 2 % of its length.
For example, if you installed 200 feet
(61 m) of plastic riser pipe, the pump
may actually be down 204 feet
(62 m). If the depth setting is critical,
check with the manufacturer of the
pipe to determine who to
compensate for pipe stretch.
The pipe manufacturer or representative should
be contacted to insure the pipe type and physical
characteristics are suitable for this use.
Use the correct joint compound recommended by
the pipe manufacturer. In addition to making sure
that joints are securely fastened, the use of a
torque arrester is recommended when using
plastic pipe.
Do not connect the first plastic or flexible riser
section directly to the pump. Always attach a
metallic nipple or adapter into the discharge
chamber of the pump. When tightened, the
threaded end of the nipple or adapter must not
come in contact with the check valve retainer in
the discharge chamber of the pump.
The drop cable should be secured to the riser
pipe at frequent intervals to prevent sagging,
looping and possible cable damage. Nylon cable
clips or waterproof tape may be used. The cable
splice should be protected by securing it with
clips or tape just above each joint.
Check valves:
A check valve should always be installed at the
surface of the well. In addition, for installations
deeper than 200 feet (61 m), check valves should
be installed at no more than 200 foot (61 m)
intervals.
Protect the well from contamination:
To protect against surface water entering the well
and contaminating the water source, the well
should be finished off above grade, and a locally
approved well seal or pitless adapter unit utilized.

3.5 Electrical

Warning
USA: All electrical work should be
performed by a qualified electrician
and installed in accordance with the
National Electrical Code, local
codes and regulations.
8
Warning
Canada: All electrical work should
be performed by a qualified
electrician and installed in
accordance with the Canadian
Electrical Code, local codes and
regulations.
Warning
To reduce the risk of electrical
shock during operation of this pump
requires the provision of acceptable
grounding. If the means of
connection to the supply connected
box is other than grounded metal
conduit, ground the pump back to
the service by connecting a copper
conductor, at least the size of the
circuit supplying the pump, to the
grounding screw provided within
the wiring compartment.
Verification of the electrical supply should be
made to ensure the voltage, phase and frequency
match that of the motor. Motor voltage, phase,
frequency and full-load current information can
be found on the nameplate attached to the motor.
Motor electrical data can be found in section
7.6.1 Grundfos submersible pump motors - 60 Hz
on p. 24.
Warning
If voltage variations are larger than
+/-10%, do not operate the pump.
Direct on-line starting is used due to the
extremely fast run-up time of the motor (0.1
second maximum), and the low moment of inertia
of the pump and motor. Direct on-line starting
current (locked rotor amp) 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, an
autotransformer or resistant starters should be
used for 5 to 30 Hp motors (depending on cable
length). For motors over 30 Hp, use auto-
transformer starters.
3.5.1 Engine-driven generators
If the submersible pump is going to be operated
using an engine driven generator, we suggest the
manufacturer of the generator be contracted to
ensure the proper generator is selected and
used. See section 7.2 Guide for engine-driven
generators in submersible pump applications on
p. 19 for generator sizing guide.
If power is going to be supplied through
transformers, section 7.3 Transformer capacity
required for three-phase submersible pump
motors on p. 20 outlines the minimum KVA rating
and capacity required for satisfactory pump
operation.
3.5.2 Control box/panel wiring
Single-phase motors
Single-phase motors must be connected as
indicated in the motor control box.