Danfoss VLT AQUA Drive Fact sheet

Fact Sheet

VLT® AQUA Drive deragging feature

keeps your wastewater pumps clean

The deragging feature has been developed
specifically for the VLT® AQUA Drive.

Wastewater from households and
industry contains particles and fibres
that are not removed by the screen
filters. The VLT® AQUA Drive deragging
feature removes clogs to protect the
pump and reduce maintenance.

Clogged impellers in wastewater
pumps can be a permanent and serious
problem. Over time, fibres and particles
will build up on the impeller vanes,
leading to poor efficiency and exten­sive wear of the pump. Clogging
reduces the capacity of the pump and
risks blocking the pump, resulting in
downtime for maintenance and ulti­mately a shorter lifetime expectency.

Avoid costly maintenance

Manually cleaning the pump is time
consuming, as maintenance staff must
travel to the site to lift, clean and
reinstall the pump; a process that often
needs special equipment.

With Deragging, Danfoss has added an
innovative pump cleaning and protec­tion feature to the VLT® AQUA Drive,
which ensures the preservation of the
maximum pump capacity by minimiz­ing deposits on the impeller. At the
same time the Deragging feature can
be optimized for the system by
configuring the delay times, the speed
and the energy monitoring system.

Proactive Deragging

With Deragging the pump cleaning can
be done proactively. During the
commissioning process, it can be
specified when the system is to
respond: At start and/or stop, at a
certain time, via digital input, via serial
communications or by using the Smart
Logic Controller.

For easy programming, all parameters
are arranged in one group.
The intelligent feature is flexible and
can be adapted to the individual
requirements of each application.

Reduce

maintenance costs
with regular de­ragging; a unique
feature that increases
pump lifetime and
eciency.

The deragging feature of the VLT® AQUA Drive provides effective protection and maximum uptime.

Clogging is a common problem, especially in wastewater pumps.

www.vlt-drives.danfoss.com

Intelligent Energy Monitoring

Power [kW/HP]

Power
high speed
Par. 29-30
Par. 29-31

Deragging activated

Power
low speed
Par. 29-26
Par. 29-27

Calculated power and
Power factor (read out)
Par. 29-20, Par. 29-21

Derag power factor
Par. 29-22

Reactive Deragging

During operation, an energy monito­ring system initiates a cleaning cycle
when pumping consumes more
energy, as it normally should do. At
this stage, the pump already starts to
with getting clogged - what proactive
deragging can prevent.

With the Danfoss VLT® AQUA Drive,
proactive and reactive deragging can
be combined. Therefore, we recom­mend to program the proactive Derag­ging, and the reactive deragging to be
carried out automatically between the
proactive deragging as needed.

Deragging Cycle

Speed

+/- Derag­speed:
Par.: 29-13
Par.: 29-14

0 Hz/RPM

Low Speed

Par. 29-24, Par. 29-25

Derag
function
activated

Derag O Delay:
Par. 29-15

High Speed

Par. 29-28, Par. 29-29

Speed [Hz/RPM]

The Cleaning Pattern

The new deragging feature of the
VLT® AQUA Drive cleans the impeller
by cyclic operation of the pump in
both directions. The user can specify
how often, how fast and how long the
impeller rotates. The graphical display
of the frequency indicates the status of
the deragging mode.

Please note that not every type of
pump can operate in the opposite
direction. Operators should always
consult the pump manufacturer before
using this function.

Time

Deragging Run Time: Par. 29-12

Number of cycles: Par. 29-10

Danfoss Drives, Ulsnaes 1, DK-6300 Graasten, Denmark, Tel. [phone], Fax [phone], www.vlt-drives.danfoss.com, E-mail: [e-mail]

DKDD.PFF.200.A2.02 © Copyright Danfoss Drives | 2015.10

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