Indian Patents. 269194:A METHOD OF MANUFACTURING A STARTING DEVICE FOR A THREE-PHASE ELECTRIC MOTOR, AND A STARTING DEVICE

Title of Invention	A METHOD OF MANUFACTURING A STARTING DEVICE FOR A THREE-PHASE ELECTRIC MOTOR, AND A STARTING DEVICE
Abstract	When manufacturing a starting device (100) for a three-phase electric motor, especially a soft starter, are quenching system (230) is at least partly removed from a commercially available contactor (200) that so becomes to a modified contactor (200B). Said modified contactor (200B) is used as contactor in the starting device (100). Independent claim also for a starting device (100).

Full Text	Description A method of manufacturing a starting device for a three-phase electric motor, and a starting device Field of the invention The invention relates to manufacturing of starting devices for three-phase electric motors especially in the higher power range suitable for operating currents larger than 29 A, and to such starting devices. Background axt If a three-phase electric motor is started directly or using star-delta starting, unpleasant side-effects such as mechanical impacts inside the machine or voltage dips in the power supply system may be encountered. To avoid these adverse effects, a so-called soft starter may be used to start-up or ramp-down a three-phase electric motor. With a soft starter, mechanical loads in the operating mechanism can be reduced, causing also less strain to the power supply system. In this manner, simple and economically more efficient use of the motor and machinery and equipment connected thereto may be achieved. A soft starter may need to be able to switch very large currents, especially if it has been adapted to start-up or ramp-down a larger motor. For example, SIEMENS soft starter SIRIUS 3RW44 is currently capable to operate a motor with a power of 710 kW at 400 V in an inline circuit, and up to 1200 kW at 400 V in an inside-delta circuit. This means that switching must be performed for single-phase currents exceeding 1000 A which is a very challenging task. Contactors, especially air contactors, are commonly used in a soft starter to protect the soft starter against electric arc and to protect the motor and machinery and equipment connected thereto against adverse effects of a bypass. The fact that contactors used in soft starters for the higher power range (for currents 29 - 1200 A and higher) are usually relatively large results in a correspondingly larger volume of the housing of a soft starter, thus increasing the material cost and making installation of the device more difficult and space-consuming. Summary of the invention A first objective of the invention is to enable reducing the size of a starting device for an electric motor or to enable increasing the size of electronics cooling system in a starting device without increasing the size of the starting device. This objective can be met with a manufacturing method as set out in claim 1. A second objective of the invention is to bring out a starting device for an electric motor that may have a smaller size. This objective can be met with a starting device as set out in claim 6. Dependent claims describe various advantageous aspects of different aspects of the invention. Advantages of the invention If in manufacturing a starting device for a three-phase electric motor, especially a soft starter, arc quenching system is at least partly removed from a commercially available contactor that so becomes modified contactor which is then used as contactor in the starting device, the starting device may be made smaller, or the thus available more space may be used for cooling the starting device, especially if the starting device has an electronic control unit. A particularly advantageous benefit is that since the contactors need not be specially manufactured, the cost for manufacturing the starting device can be kept low. In particular, the starting device may be made smaller by removing an arc splitter chamber completely or in part, since the arc splitter chamber is usually relatively large. Further size reduction can be obtained if at least one de-ion plate is removed. The starting device may be made more stabile and robust against external forces, such as strain and torque, if external contact members of the starting device are connected to contact members of the modified contactor. The stability may be further improved by connecting an electronic control unit in parallel to said modified contactor from contact members of the modified contactor or from contact members of the starting device. Because the modified contactor is smaller than the commercially available contactor, it becomes easier to make the parallel connection for the electronic control unit since it the contact members become better accessible. In particular, if said commercially available contactor is an air contactor, the space saving may be considerable. List of drawings In the following, the invention will be described in more detail with reference to examples in the accompanying drawings in Figures 1 to 3, of which: Figure 1 illustrates a starter device; Figure 2 illustrates a commercially available contactor; and Figure 3 illustrates a modified contactor. Same reference numerals refer to similar structural elements throughout the Figures. Detailed description Figure 1 shows a starting device 100 that is a soft starter. The starting device 100 may be connected to power lines (not shown) via its contact members 101, of which there is preferably one contact member 101 for each phase, and to a three-phase electric motor (not shown) via its contact members 102, likewise of which there is preferably one contact member 102 for each phase. The starting device 100 comprises a user interface unit 110 that preferably remains visible from the cover (not shown) of the housing. The user may control the functioning of the starting device 100 via the user interface unit 110, e.g. set the operation current of the motor, or command the starting device 100 to start-up or ramp-down the electric motor. The starting device 100 further comprises an electronic control unit 120 that in Figure 1 is shown partly covered by a support panel 130. The electronic control unit 120 preferably comprises thyristors that may be used to control the start-up or ramp-down current of the electric motor which is sometimes referred to as semiconductor control. In particular, the starting device 100 is adapted to switch the current instead of the electronic control unit 120 by contactor 200B as soon as the operation current of the motor has been reached or is about to be reached. The main reason for this is that a contactor 200B has much better energy efficiency than the semiconductor control, where heat dissipation of up to 3 W/A may be encountered, which would cause extensive heating up of the starting device with norm operating current of 880 A, for example. The contactor 200B is preferably contacted to the power lines and the motor by contacting its contact members 215, 225 to contact members 101, 102, respectively. Figure 2 shows a commercially available contactor 200 that has been used in prior start devices. The commercially available contactor 200 is preferably suitable to be used within the higher power range, i.e. with currents larger than 29 A. A commercially available contactor 200 usually comprises a mounting base 210, a contactor part 220, and an arc quenching system 230. According to one aspect of the invention, before or during construction of the starting device 100, a commercially available contactor 200 is first .modified to a modified contactor 200B and the modified contactor 200B is then used as contactor when assembling the starting device 100. Figure 3 shows a modified contactor 200B. When performing the modifying, arc quenching system 230 is at least partly but preferably fully removed from the commercially available contactor 200 that so becomes to a modified contactor 200B. For SIRIUS 3RT14 air contactors, for example, this can be performed with a screw driver, since the arc quenching system is in a particular module that has been attached to the contactor 200 by screws. Sawing or other more powerful measures can nevertheless be used alone or in combination with the screw driver to get rid of the arc quenching system 230 or to make it smaller. Depending on the contactor 200, in the modified contactor 200B the movable contact elements 240 may thus become visible. Basically, the art quenching system 230 comprises an arc splitter chamber which may be a chamber filled with air. The arc splitter chamber may further comprise a series of de-ion plates, the function of which is to split the voltage causing the electric arc to smaller voltages, thereby efficiently eliminating the electric arc. Some or all walls of the arc splitter chamber may thus be removed, and if still more size reduction is necessary, some or preferably all of the de-ion plates may be dismounted or removed, fully or in part. That the modified contactor 200B does not comprise an arc quenching system 230 any more does not cause a problem, since during starting-up and ramping-down of the motor, the current is controlled by the electronic control unit 120 through thyristors, where usually no arcing will take place. After finishing starting-up, when the current fed to the motor has reached the operation current, the electronic control unit 120 and the modified contactor 200B are run in parallel for a moment before the current is passed fully through the modified contactor 200B. Because the switching from the electronic control unit 120 to the modified contactor 200B does not involve change of load, there will be no arcing. Before starting ramping-down, the electronic control unit 120 and the modified contactor 200B are again run in parallel before the current is passed fully through the electronic control unit 120. Because the switching from the electronic control unit 120 to the modified contactor 200B does not involve change of load, there will be no arcing. Even though the invention has been described by using particular examples, the skilled person readily appreciates that the invention is by no means limited to these but can be interpreted within the scope and spirit of the accompanying claims. In particular, the commercially available contactor 200 may be an air contactor. Claims 1. A method of manufacturing a starting device (100) for a three-phase electric motor, especially a soft starter, wherein the improvement comprises the steps of: at least partly removing arc quenching system (230) from a commercially available contactor (200) that so becomes to a modified contactor (200B); and using said modified contactor (200B) as contactor in the starting device (100). i 2. A method according to claim 1, wherein: in the step of at least partly removing arc quenching system (230) an arc splitter chamber is removed completely or in part. 3. A method according to claim 2, wherein: in the step of at least partly removing arc quenching system (230) at least one, preferably all, de-ion plates are removed completely or in part. 4. A method according to any one of claims 1 to 3, further comprising the step of: connecting external contact members (101) of the starting device (100) to contact members (215) of the modified contactor (200B). 5. A method according to claim 4, wherein: an electronic control unit (120) is connected in parallel to said modified contactor (200B) from contact members (215) of the modified contactor (200B) or from contact members (101) of the starting device (100) . 6. A starting device (100) for a three-phase electric motor, especially a soft starter, comprising: a modified contactor (200B) made from a commercially available contactor (200) from which arc quenching system (230) has at least partly been removed. 7. A starting device (100) according to claim 6, wherein: of the arc quenching system (230), an arc splitter chamber or at least one, preferably all, de-ion plates have been removed completely or in part. 8. A starting device (100) according to claim 6 or 7, further comprising: external contact members (101) connected to contact members (215) of the modified contactor (200B). 9. A starting device (100) according to claim 8, further comprising: an electronic control unit (120) that has been connected in parallel to said modified contactor (200B) from contact members (215) of the modified contactor (200B) or from contact members (101) of the starting device (100). 10. A starting device (100) or a method according to any one of the preceding claims, wherein: said commercially available contactor (200) is an air contactor. When manufacturing a starting device (100) for a three-phase electric motor, especially a soft starter, are quenching system (230) is at least partly removed from a commercially available contactor (200) that so becomes to a modified contactor (200B). Said modified contactor (200B) is used as contactor in the starting device (100). Independent claim also for a starting device (100).

Full Text

Description
A method of manufacturing a starting device for a three-phase
electric motor, and a starting device
Field of the invention
The invention relates to manufacturing of starting devices
for three-phase electric motors especially in the higher
power range suitable for operating currents larger than 29 A,
and to such starting devices.
Background axt
If a three-phase electric motor is started directly or using
star-delta starting, unpleasant side-effects such as
mechanical impacts inside the machine or voltage dips in the
power supply system may be encountered.
To avoid these adverse effects, a so-called soft starter may
be used to start-up or ramp-down a three-phase electric
motor. With a soft starter, mechanical loads in the operating
mechanism can be reduced, causing also less strain to the
power supply system. In this manner, simple and economically
more efficient use of the motor and machinery and equipment
connected thereto may be achieved.
A soft starter may need to be able to switch very large
currents, especially if it has been adapted to start-up or
ramp-down a larger motor. For example, SIEMENS soft starter
SIRIUS 3RW44 is currently capable to operate a motor with a
power of 710 kW at 400 V in an inline circuit, and up to 1200
kW at 400 V in an inside-delta circuit. This means that
switching must be performed for single-phase currents
exceeding 1000 A which is a very challenging task.
Contactors, especially air contactors, are commonly used in a
soft starter to protect the soft starter against electric arc

and to protect the motor and machinery and equipment
connected thereto against adverse effects of a bypass.
The fact that contactors used in soft starters for the higher
power range (for currents 29 - 1200 A and higher) are usually
relatively large results in a correspondingly larger volume
of the housing of a soft starter, thus increasing the
material cost and making installation of the device more
difficult and space-consuming.
Summary of the invention
A first objective of the invention is to enable reducing the
size of a starting device for an electric motor or to enable
increasing the size of electronics cooling system in a
starting device without increasing the size of the starting
device. This objective can be met with a manufacturing method
as set out in claim 1.
A second objective of the invention is to bring out a
starting device for an electric motor that may have a smaller
size. This objective can be met with a starting device as set
out in claim 6.
Dependent claims describe various advantageous aspects of
different aspects of the invention.
Advantages of the invention
If in manufacturing a starting device for a three-phase
electric motor, especially a soft starter, arc quenching
system is at least partly removed from a commercially
available contactor that so becomes modified contactor which
is then used as contactor in the starting device, the
starting device may be made smaller, or the thus available
more space may be used for cooling the starting device,
especially if the starting device has an electronic control
unit.

A particularly advantageous benefit is that since the
contactors need not be specially manufactured, the cost for
manufacturing the starting device can be kept low.
In particular, the starting device may be made smaller by
removing an arc splitter chamber completely or in part, since
the arc splitter chamber is usually relatively large. Further
size reduction can be obtained if at least one de-ion plate
is removed.
The starting device may be made more stabile and robust
against external forces, such as strain and torque, if
external contact members of the starting device are connected
to contact members of the modified contactor. The stability
may be further improved by connecting an electronic control
unit in parallel to said modified contactor from contact
members of the modified contactor or from contact members of
the starting device.
Because the modified contactor is smaller than the
commercially available contactor, it becomes easier to make
the parallel connection for the electronic control unit since
it the contact members become better accessible.
In particular, if said commercially available contactor is an
air contactor, the space saving may be considerable.
List of drawings
In the following, the invention will be described in more
detail with reference to examples in the accompanying
drawings in Figures 1 to 3, of which:
Figure 1 illustrates a starter device;
Figure 2 illustrates a commercially available contactor; and
Figure 3 illustrates a modified contactor.

Same reference numerals refer to similar structural elements
throughout the Figures.
Detailed description
Figure 1 shows a starting device 100 that is a soft starter.
The starting device 100 may be connected to power lines (not
shown) via its contact members 101, of which there is
preferably one contact member 101 for each phase, and to a
three-phase electric motor (not shown) via its contact
members 102, likewise of which there is preferably one
contact member 102 for each phase.
The starting device 100 comprises a user interface unit 110
that preferably remains visible from the cover (not shown) of
the housing. The user may control the functioning of the
starting device 100 via the user interface unit 110, e.g. set
the operation current of the motor, or command the starting
device 100 to start-up or ramp-down the electric motor.
The starting device 100 further comprises an electronic
control unit 120 that in Figure 1 is shown partly covered by
a support panel 130. The electronic control unit 120
preferably comprises thyristors that may be used to control
the start-up or ramp-down current of the electric motor which
is sometimes referred to as semiconductor control.
In particular, the starting device 100 is adapted to switch
the current instead of the electronic control unit 120 by
contactor 200B as soon as the operation current of the motor
has been reached or is about to be reached. The main reason
for this is that a contactor 200B has much better energy
efficiency than the semiconductor control, where heat
dissipation of up to 3 W/A may be encountered, which would
cause extensive heating up of the starting device with norm
operating current of 880 A, for example.

The contactor 200B is preferably contacted to the power lines
and the motor by contacting its contact members 215, 225 to
contact members 101, 102, respectively.
Figure 2 shows a commercially available contactor 200 that
has been used in prior start devices. The commercially
available contactor 200 is preferably suitable to be used
within the higher power range, i.e. with currents larger than
29 A. A commercially available contactor 200 usually
comprises a mounting base 210, a contactor part 220, and an
arc quenching system 230. According to one aspect of the
invention, before or during construction of the starting
device 100, a commercially available contactor 200 is first
.modified to a modified contactor 200B and the modified
contactor 200B is then used as contactor when assembling the
starting device 100.
Figure 3 shows a modified contactor 200B. When performing the
modifying, arc quenching system 230 is at least partly but
preferably fully removed from the commercially available
contactor 200 that so becomes to a modified contactor 200B.
For SIRIUS 3RT14 air contactors, for example, this can be
performed with a screw driver, since the arc quenching system
is in a particular module that has been attached to the
contactor 200 by screws. Sawing or other more powerful
measures can nevertheless be used alone or in combination
with the screw driver to get rid of the arc quenching system
230 or to make it smaller. Depending on the contactor 200, in
the modified contactor 200B the movable contact elements 240
may thus become visible.
Basically, the art quenching system 230 comprises an arc
splitter chamber which may be a chamber filled with air. The
arc splitter chamber may further comprise a series of de-ion
plates, the function of which is to split the voltage causing
the electric arc to smaller voltages, thereby efficiently
eliminating the electric arc. Some or all walls of the arc

splitter chamber may thus be removed, and if still more size
reduction is necessary, some or preferably all of the de-ion
plates may be dismounted or removed, fully or in part.
That the modified contactor 200B does not comprise an arc
quenching system 230 any more does not cause a problem, since
during starting-up and ramping-down of the motor, the current
is controlled by the electronic control unit 120 through
thyristors, where usually no arcing will take place.
After finishing starting-up, when the current fed to the
motor has reached the operation current, the electronic
control unit 120 and the modified contactor 200B are run in
parallel for a moment before the current is passed fully
through the modified contactor 200B. Because the switching
from the electronic control unit 120 to the modified
contactor 200B does not involve change of load, there will be
no arcing.
Before starting ramping-down, the electronic control unit 120
and the modified contactor 200B are again run in parallel
before the current is passed fully through the electronic
control unit 120. Because the switching from the electronic
control unit 120 to the modified contactor 200B does not
involve change of load, there will be no arcing.
Even though the invention has been described by using
particular examples, the skilled person readily appreciates
that the invention is by no means limited to these but can be
interpreted within the scope and spirit of the accompanying
claims.
In particular, the commercially available contactor 200 may
be an air contactor.

Claims
1. A method of manufacturing a starting device (100) for a
three-phase electric motor, especially a soft starter,
wherein the improvement comprises the steps of:
at least partly removing arc quenching system (230) from
a commercially available contactor (200) that so becomes
to a modified contactor (200B); and
using said modified contactor (200B) as contactor in the
starting device (100).
i
2. A method according to claim 1, wherein: in the step of at
least partly removing arc quenching system (230) an arc
splitter chamber is removed completely or in part.
3. A method according to claim 2, wherein: in the step of at
least partly removing arc quenching system (230) at least
one, preferably all, de-ion plates are removed completely or
in part.
4. A method according to any one of claims 1 to 3, further
comprising the step of: connecting external contact members
(101) of the starting device (100) to contact members (215)
of the modified contactor (200B).
5. A method according to claim 4, wherein: an electronic
control unit (120) is connected in parallel to said modified
contactor (200B) from contact members (215) of the modified
contactor (200B) or from contact members (101) of the
starting device (100) .
6. A starting device (100) for a three-phase electric motor,
especially a soft starter, comprising: a modified contactor
(200B) made from a commercially available contactor (200)
from which arc quenching system (230) has at least partly
been removed.

7. A starting device (100) according to claim 6, wherein: of
the arc quenching system (230), an arc splitter chamber or at
least one, preferably all, de-ion plates have been removed
completely or in part.
8. A starting device (100) according to claim 6 or 7,
further comprising: external contact members (101) connected
to contact members (215) of the modified contactor (200B).
9. A starting device (100) according to claim 8, further
comprising: an electronic control unit (120) that has been
connected in parallel to said modified contactor (200B) from
contact members (215) of the modified contactor (200B) or
from contact members (101) of the starting device (100).
10. A starting device (100) or a method according to any one
of the preceding claims, wherein: said commercially available
contactor (200) is an air contactor.

When manufacturing a starting device (100) for a three-phase electric motor, especially a soft starter, are quenching system (230) is at least partly removed from a commercially available
contactor (200) that so becomes to a modified contactor (200B). Said modified contactor (200B) is used as contactor in the starting device (100). Independent claim also for a starting
device (100).

Documents:

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Patent Number

269194

Indian Patent Application Number

1557/KOLNP/2008

PG Journal Number

41/2015

Publication Date

09-Oct-2015

Grant Date

08-Oct-2015

Date of Filing

17-Apr-2008

Name of Patentee

SIEMENS AKTIENGESELLSCHAFT

Applicant Address

WITTELSBACHERPLATZ 2, 80333 MUNCHEN

Inventors:

#	Inventor's Name	Inventor's Address
1	MARCO DORNAUER	PETER-VISCHER-WEG 6 90562 HEROLDSBERG
2	PETER SCHLEGL	ZUM BIRKENSCHLAG 19 A 90518 ALTDORF
3	MARKUS MEIER	BLUMENTHALSTR. 27 92286 RIEDEN

PCT International Classification Number

H02P 1/28, H01H 9/54

PCT International Application Number

PCT/EP2005/012441

PCT International Filing date

2005-11-21

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA