AD437153353153en-010301.pdf - 第4页
Centrifugal pump – W ater Need to reduce water pr essure surges and mains supply disturbance at star t- up? Then a gentle star t using a soft star ter is a good idea. It also provides a soft stop to control the effects o…
0 200,00 400,00 600,00 800,00 1000,00 1200,00
Savings
in €
70% running
30% ramping
80% running
20% ramping
95% running
5% ramping
No
bypass
External
bypass
Integrated
bypass,
MCD 600
Integrated bypass – for all-round savings
Many Danfoss soft starters provide an
integrated bypass to allow direct-on-
line operation as an alternative. The
integrated bypass offers multiple cost-
saving benefits.
Reduce heat loss
Integrated bypass provides the
opportunity to switch over to direct-
on-line operation, after initial start-up
via the soft starter. By running partially
direct-on-line, you win the advantages
of reduced losses and need for heat
dissipation, thus saving energy due to
decreased cooling requirements.
Save space
Danfoss soft starters with integrated
bypass take up less panel space than a
soft starter with an external contactor.
Save time
With only six terminals instead of
twelve, it is much faster to wire a VLT®
Soft Starter with integrated bypass,
than an alternative soft starter with
external contactor. Less cable is
required, which additionally reduces
cost. Save even more time, by using
the handy set-up software tool
VLT® Motion Control Tool MCT 10 to
configure the soft starter via PC.
You can use the same set-up tool with
VLT® drives.
Save energy – fast payback
The soft starter with integrated bypass
contactor saves space by comparison
to an external contactor connected to
a non-bypassed unit.
Select a soft starter with integrated
bypass when you want to save costs.
The payback time is just months, using
a Danfoss soft starter with integrated
bypass. See how in this example:
Example: VLT® Soft Starter MCD 600
In the example, a VLT® Soft Starter MCD 600 regulates a water pump,
with motor specifications as follows:
Motor
Supply ....................................................................................400 V AC
Rating .....................................................................................132 kW
FLC ...........................................................................................244 A
Start duty .............................................................................300% for 30 seconds
Electricity prices...............................................................(industry – EU)
Estimated savings, non-bypassed versus bypassed
Save more with bypass, compared to no bypass.
The energy saved depends on the relationship between ramping and running.
The more the application is running the more the bypass will save – see illustration.
Cost saving using a bypass, showing the beneficial savings effect
of increased running time and reduced ramping time.
Integrated bypass versus external bypass
Win back your investment faster with integrated bypass, compared to external
bypass. The payback period is only a few months.
Investment
(indexed values)
No bypass,
Direct-on-line
Soft starter with
external bypass
Soft starter with
integrated bypass
VLT® Soft Starter MCD 600
Soft starter 100 100 100
Bypass contactor + wiring
+ mounting
0 58 58
Extra panel space, parts,
and labour
0 3 3
Total 100 161 161
Extra cost compared
to no bypass
- 61 61
Simple payback period
[months]
– 3.3 3.3
AD437153353153en-010301 > VLT® Soft Starter
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Centrifugal pump
– Water
Need to reduce water pressure surges
and mains supply disturbance at start-
up? Then a gentle start
using a soft starter is a good idea.
It also provides a soft stop to control
the effects of fluid hammer often
associated with uncontrolled pump
stop – ultimately extending pump
life and reducing running costs. For
new projects, build these savings in
at design phase – there is no need
to specify pressure surge tanks and
motorized valves to cater for repetitive
high-pressure surges. The minimum
start current function reduces
electrical disturbance on mains supply
and limits demand on supply as well –
reducing reticulation costs for
example in farmland irrigation projects.
The soft starter
• Prevents motor overheating via
integrated protection
• Ensures that pump does not run in
reverse, via start-up protection
• Detects blocked pipes or lack of
fluid via undercurrent protection,
thus preventing unnecessary pump
damage
Centrifugal fan
– HVAC
Extend the life of centrifugal fans
by adding a soft starter – to ensure
gentle acceleration and deceleration,
minimizing wear on coupling, belts,
and bearings.
The soft starter
• Reduces electrical disturbance on the
supply via a minimal start current
• Prevents overheating of motor
windings and body
• Prevents starting when fan direction
is reversed, avoiding damage
• Trips in the event of excess start time,
indicating a jammed or stalled fan,
also providing early indication of
bearing failure
• Detects broken couplings and belts
or clogged fan filter, via and optional
trip or flag for motor undercurrent
To integrate the soft starter directly
with a BMS, the VLT® Soft Starter MCD
600 supports monitoring fan loading,
without the need for extra equipment
an analog output.
Compressor
– Protect your motor
Has the compressor ever locked up,
for instance due to entry of liquid
ammonia? Using a soft starter,
ongoing monitoring prevents damage
to motor, compressor, and couplings in
a lock up situation.
Soft starters provide instant protection
against motor overload, by tripping
the motor immediately.
The soft starter
• Enables load shedding before the soft
starter trips, for compressor overload
or motor overtemperature
• Trips to prevent motor damage
when start-up time exceeds a pre-
programmed limit, for example due
to a jammed or stalled compressor
• Monitors the compressor load using a
0-20 mA/4-20 mA analog output
• Enables optimized compressor
performance with dual speed
dahlander motor control
• Avoids short cycling via restart delay,
promoting longer life of motor,
compressor, and coupling
• Is an easy retrofit for start/delta
starters
Applications
AD437153353153en-010301 > VLT® Soft Starter 4
Conveyor belt – Food and
beverage industries
Extend the life of your conveyor belt,
and gain the benefit of consistent
start-up regardless of whether the
belt is loaded or not. The soft starter
ensures gentle acceleration and
deceleration, reducing risk of product
damage due to jerky starts and sudden
stops. It also protects the couplings,
belts, and bearings against mechanical
wear.
The soft starter
• Prevents conveyor belt slap during
start
• Reduces stress on counter- balances
and weights
• Reduces electrical disturbance on the
supply, via a minimum start current
function
• Provides protection against
accidental running in reverse
• Detects broken couplings or
broken belts, and trips the motor
immediately
• Detects overload, or a jammed
or stalled conveyor, and protects
equipment by tripping the motor
immediately
Crusher and mill
– Mining
Maximise your crusher or mill
throughput by installing a soft starter
at the motor input. The soft starter
allows the motor to operate at its
upper thermal limit, while carefully
monitoring thermal capacity to ensure
motor protection. The crusher can
then safely ride through temporary
product overload situations
The soft starter
• Eliminates the need for special
control equipment, by connecting
motor thermistors directly into the
VLT® Soft Starter MCD 600 thermistor
input
• Extends the life of couplings, belts,
and bearings by gentle start-up,
minimizing torque transients
• Reduces electrical disturbance on the
supply
• Limits the demand on the supply,
especially critical on remote sites
supplied by generator sets
• Prevents damage due to
unintentional running in reverse, by
preventing start when rotation of the
3-phase incoming supply changes
• Detects broken couplings and
broken crusher belts via undercurrent
protection, and trips to prevent
further damage
AD437153353153en-010301 > VLT® Soft Starter
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