English (GB)
17
7.4 Submerged installation, temporary
Proceed as follows:
1. Fit the ring stand to the pump suction flange.
2. Fit a 90 ° elbow to the pump discharge port and connect the
discharge pipe/hose.
If a hose is used, make sure that the hose does not buckle and
that the inside diameter matches that of the discharge port.
3. Lower the pump into the liquid by means of a chain secured to
the lifting bracket of the pump. It is recommended to place the
pump on a plane, solid foundation. Make sure that the pump is
hanging from the chain and not the cable.
4. Hang up the end of the chain on a suitable hook at the top of
the tank and in such a way that the chain cannot come into
contact with the pump housing.
5. Adjust the length of the motor cable by coiling it up on a relief
fitting to ensure that the cable is not damaged during
operation. Fasten the relief fitting to a suitable hook. Make
sure that the cables are not sharply bent or pinched.
6. Connect the motor cable and the control cable, if any.
7.5 Pump controllers
SE/SL pumps, 9-30 kW, can be connected to a separate
Grundfos pump controller for level control, which is available as
an accessory:
• type LC for one-pump installations
• type LCD for two-pump installations
• Grundfos Dedicated Controls for one to six pumps.
Depending on the application, different types of level control
equipment can be used:
The LC controller is fitted with two or three level switches. Two
for start and stop of the pump. The third level switch, which is
optional, is for high-level alarm.
The LCD controller is fitted with three or four level switches. One
for common stop and two for start of the pumps. The fourth level
switch, which is optional, is for high-level alarm.
The Grundfos Dedicated Controls is a control system designed
for installation in either commercial buildings or network pumping
stations with up to six pumps. Advanced control and data
communication is also possible with the Grundfos Dedicated
Controls system.
The Dedicated Controls system consists of the following
components:
• CU 361 control unit
• IO 351B module (general I/O module)
• IO 113 protection module (optional).
The Dedicated Controls system starts/stops the wastewater
pumps by means of the following devices:
• float switches
• analog pressure sensor
• ultrasonic sensor.
Furthermore, it is possible to control the water level by combining
float switches with an analog pressure sensor. Two additional
safety float switches can be installed in the Dedicated Controls
system for high-level and dry-running alarm.
When installing the level switches, please observe the following:
• To prevent air intake and vibrations in submerged pumps, fit
the stop level switch in such a way that the pump is stopped
before the liquid level is lowered below the top of the pump
housing. As a principal rule for pumps in dry installation, the
lowest stop level must be at least 20 cm above the opening of
the suction pipe. See fig. 9.
• Install the start level switch in such a way that the pump is
started at the required level; however, the pump must always
be started before the liquid level reaches the bottom inlet pipe
to the tank.
• If applicable, always install the high-level alarm switch about
10 cm above the start level switch; however, alarm must
always be given before the liquid level reaches the inlet pipe to
the tank.
8. Electrical connection
The supply voltage and frequency are marked on the pump
nameplate.
The voltage tolerance at the motor terminals must be within
- 10 %/+ 10 % of the rated voltage.
Make sure that the motor is suitable for the power supply
available at the installation site.
The motor is effectively earthed via the power cable and
pipework. The motor top cover is equipped with connections for
external earthing or an equipotential bonding conductor.
The pump must be connected to a motor-protective circuit
breaker.
The most commonly used start-up methods are direct-on-line
starting (DOL), see appendix fig. 2, star-delta starting (Y/D), see
appendix fig. 1, and soft start. The pump can even be started via a
frequency converter according to the frequency converter
manufacturer’s specifications. See section 8.2 Frequency converter
operation. The selection of suitable starting method depends on
several considerations on usage and mains supply conditions.
Warning
The pump must be connected to an external main
switch with a contact separation according to
EN 60204-1, 5.3.2.
The electrical connection must be carried out in
accordance with local regulations.
Warning
Before installation and the first start-up of the
pump, check the condition of the cable visually to
avoid short circuits.
When using star-delta starting, it is important to
keep switching transient time to a minimum to
avoid high transient torques. We recommend to
use a time relay with a switching time of
maximum 50 ms or according to the starter
manufacturer’s specifications.
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