ABB Softstarters User Manual

SOFTSTARTER HANDBOOK

FOREWORD

This book is written with the thought of being a general guide for people working with softstarter applications but also for those just interested in learning more about this type of starting method. It doesn’t matter if you are an expert or novice, hopefully you will find some interesting and useful information either by reading from cover to cover or just the chapters of interest. The index at the end of the book can be used to simplify your search.

The content of this book is very much based on the 20 years of experience we have within ABB of developing, manufacturing and selling low voltage softstarters. The book is not a complete technical guide or manual for all type of ABB Softstarters that may exist on the market. It is a complement to the technical catalogues and brochures we have for our products and will give a general picture of what to think about when working with softstarters. More information about softstarters as well as other ABB products is available on www.abb.com

All advice given in this book is only general and every single application must be handled as a specific case.

ABB Automation Technology Products AB, Control February 2003

Magnus Kjellberg Sören Kling

ABB will not take any responsibility for any type of faults or damage due to the use of this handbook.

Standards ...1

European Directives ...1 CE Marking ...1 Specification in USA and Canada ...1 Used standards ...1

General about motors ...2

Squirrel cage motors ...3 Voltage ...4 Power factor ...5 Speed ...6 Torque ...7 Slip-ring motors ...7

Different starting methods ...8

Direct-on-line start (D.O.L) ...9 Star-delta start ...10 Frequency converter ...12 Softstarter ...13 Common problem when starting and stopping motors ...14

Different applications ...15

Centrifugal fan ...16

Direct-on-line start (D.O.L) ...16 Star-delta start ...17 Softstarter ...17 Selection of a suitable Softstarter ...18

Contents

Centrifugal pump ...19

Direct-on-line start (D.O.L) ...19 Star-delta start ...20 Softstarter ...21 Selection of a suitable Softstarter ...22

Compressor ...23

Direct-on-line start (D.O.L) ...23 Star-delta start ...24 Softstarter ...25

Contents

Selection of a suitable Softstarter ...26

Conveyor belt ...27

Direct-on-line start (D.O.L) ...27 Star-delta start ...28 Softstarter ...29 Selection of a suitable Softstarter ...30

How to select a softstarter ...31 Description of the softstarters ...33

Description of different components ...34

Common settings ...36

Start ramp ...36 Stop ramp ...36 Initial voltage ...36 Current limit ...37 Step down voltage ...38 Adjustable rated motor current ...38

Different indications ...39

Different voltage names ...40 Ambient temperature ...41 High altitudes ...42

Start of several motors ...43

Parallel start of motors ...43 Sequential start of motors ...44

Different ways of connecting the softstarter ...45

In-Line connection ...46 Inside Delta connection ...46 Location of the main contactor ...47

Basic settings ...49

Table for settings without current limit function ...50 Table for settings with current limit function ...51

Starting capacity and overload protection ...52

Starting capacity for softstarters ...52 Starting capacity when using by-pass contactor ...53 Starting capacity when using overload protection ...53

Number of starts/hour ...54

Intermittance factor ...54

Contents

Harmonics ...55

Harmonic content ...55

Explosive atmospheres (EEx) ...56

Hazardous areas and zones ...57 Location and selection of softstarter ...57

Co-ordination ...58

Types of co-ordination ...59 Utilization Categories ...60 Types of fuses ...61 Where to find the co-ordination tables ...62 How to read the co-ordination tables ...63

ESD aspects ...65

Two type of faults and different circuits ...65 Electro static voltage levels ...66 Protection against ESD damages ...66

III

Frequently Asked Questions (FAQ) ...67 Environmental information ...69

LCA ...69

Contents

EPD ...70

Industrial IT ...71

Different levels ...72 Softstarter level ...72

Formulas and conversion factors ...73

Formulas ...73 Quantities and units ...75 Conversion factors ...76

Glossary ...78

Index ...84

Standards

All ABB low voltage softstarters are developed and manufactured according to the rules set out in the IEC (International Electrotechnical Commission) which is a part of the International Standard Organisation, ISO. ISO issue IEC publications that act as a basis for the world market.

Softstarters built according to these standards are in most countries not subject to any other tests besides the manufacturer responsibility. In some countries, law requires certificates.

For softstarters used on board ships, maritime insurance companies sometimes require certificates of approval from BV (Bureau Veritas), GL (Germanisher Lloyd) and LRS (Lloyd’s Register of Shipping) or other independent certification organisation.

European Directives

There are three essential European directives:

Low Voltage Directive 73/23/EEC

Concerns electrical equipment from 50 to

1000 V AC and from 75 to 1500 V DC.

Machines Directive 89/392/EEC

Concerns safety specifications of machines

and equipment on complete machines.

Electromagnetic Compatibility Directive

89/336/EEC

Concerns all devices able to create electro-

magnetic disturbance including the level of

emission and immunity.

CE Marking

When a product is verified according to its applicable IEC standard (IEC 947-4-2 for softstarters) the product will then fulfil both the ”Lown Voltage Directive” and ”Electromagnetic Compability Directive” and it is allowed to use the CE marking on the product. In this case the CE marking does not cover the ”Machines Directive” concerning the connection of the softstarter for a safe run of the motor. The CE marking is not a quality label; it is proof of conformity with the European Directives concerning the product.

Specifications in USA and Canada

The specifications for the American and Canadian markets are quite equal but differ a lot from the IEC standards and other European specifications.

USA UL Underwriters Laboratories

File ref. 072301-E161428

110800-E161428

Canada CSA Canadian Standards

File ref. 1031179

Used standards

Following standards are used or partly used for the softstarters.

IEC 60947-1 IEC 60947-1/A11 IEC 60947-4-2, Amd 1 EN 50082-2 UL 508 CSA C22.2 No. 14 - M91 LRS 00/00154

Standards

About Motors

Modern electrical motors are available in many different forms, such as single phase motors, three-phase motors, brake motors, synchronous motors, asynchronous motors, special customised motors, two speed motors, three speed motors, and so on, all with their own performance and characteristics.

For each type of motor there are many different mounting arrangements, for example foot mounting, flange mounting or combined foot and flange mounting. The cooling method can also differ very much, from the simplest motor with free self-circulation of

About Motors

air to a more complex motor with totally enclosed air-water cooling with an interchangeable cassette type of cooler.

To ensure a long lifetime for the motor it is important to keep it with the correct degree of protection when under heavy-duty conditions in a servere environment. The two letters IP (International Protection) state the degree of protection followed by two digits, the first of which indicates the degree of protection against contact and penetration of solid objects, whereas the second states the motor’s degree of protection against water.

The end of the motor is defined in the IEC-standard as follows:

• The D-end is normally the drive end of the motor.

• The N-end is normally the non-drive end of the motor.

Note that in this handbook we will focus on asynchronous motors only.

Drive shaft

Stator windings

Terminal box

Cooling fan

N-endD-end

Stator

Rotor

Squirrel cage motors

In this book the focus has been placed on the squirrel cage motor, the most common type of motor on the market. It is relatively cheap and the maintenance cost is normally low. There are many different manufacturers represented on the market, selling at various prices. Not all motors have the same performance and quality as for example motors from ABB. High efficiency enables significant savings in energy costs during the motor’s normal endurance. The low level of noise is something else that is of interest today, as is the ability to withstand severe environments.

There are also other parameters that differ. The design of the rotor affects the starting current and torque and the variation can be really large between different manufacturers for the same power rating. When using a softstarter it is good if the motor has a high starting torque at Direct-on-line (D.O.L) start. When these motors are used together with a softstarter it is possible to reduce the starting current further when compared to motors with low starting torque. The number of poles also affects the technical data. A motor with two poles often has a lower starting torque than motors with four or more poles.

About Motors

Current diagram for typical sqirrel cage motor

Max. starting current

Rated current

rpm

Starting torque

Torque diagram for a typical squirrel cage motor

Max. torque

Rated torque

rpm

Voltage

Three-phase single speed motors can normally be connected for two different voltage levels. The three stator windings are connected in star (Y) or delta (D).

The windings can also be connected in series or

About Motors

parallel, Y or YY for instance. If the rating plate on a squirrel cage motor indicates voltages for both the star and delta connection, it is possible to use the motor for both 230 V, and 400 V as an example.

The winding is delta connected at 230 V and if the main voltage is 400 V, the Y-connection is used.

When changing the main voltage it is important to remember that for the same power rating the rated motor current will change depending on the voltage level.

The method for connecting the motor to the terminal blocks for star or delta connection is shown in the picture below.

V2 V1

– Connection 230 V (400 V)

Wiring diagram for Y- and Delta connection

W1U1 V1

V2W2 U2

W1U1 V1

L3L1 L2

Y – Connection

400 V

(690 V)

Power factor

A motor always consumes active power, which it converts into mechanical action. Reactive power is also required for the magnetisation of the motor but it doesn’t perform any action. In the diagram below the active and reactive power is represented by P and Q, which together give the power S.

The ratio between the active power (kW) and the reactive power (kVA) is known as the power factor, and is often designated as the cos ϕ. A normal value is between 0.7 and 0.9, when running where the lower value is for small motors and the higher for large ones.

About Motors

Diagram indicating P, Q, S and Cos ϕ

Speed

The speed of an AC motor depends on two things: the number of poles of the stator winding and the main frequency. At 50 Hz, a motor will run at a speed related to a constant of 6000 divided by the number of poles and for a 60 Hz motor the constant is 7200 rpm.

About Motors

To calculate the speed of a motor, the following formula can be used:

2 x f x 60

n =

n = speed f = net frequency p = number of poles

Example:

4-pole motor running at 50 Hz

2 x 50 x 60

n =

This speed is the synchronous speed and a squirrel-cage or a slip-ring motor can never reach it. At unloaded condition the speed will be very close to synchronous speed and will then drop when the motor is loaded.

= 1500 rpm

The difference between the synchronous and asynchronous speed also named rated speed is ”the slip” and it is possible to calculate this by using the following formula:

n1 - n

s =

s = slip (a normal value is between 1 and 3 %)

n1 = synchronous speed n = asynchronous speed (rated speed)

Table for synchronous speed at different number of poles and frequency:

No. of poles 50 Hz 60 Hz

2 3000 3600

4 1500 1800

6 1000 1200

8 750 900

10 600 720

12 500 600

16 375 450

20 300 360

Diagram showing syncronous speed vs.rated speed

Rated speed

Syncronous speed

}

rpm

Slip

Torque

The starting torque for a motor differs significantly depending on the size of the motor. A small motor, e.g. ≤ 30 kW, normally has a value of between 2.5 and 3 times the rated torque, and for a medium size motor, say up to 250 kW, a typical value is between 2 to 2.5 times the rated torque. Really big motors have a tendency to have a very low starting torque, sometimes even lower than the rated torque. It is not possible to start such a motor fully loaded not even at D.O.L start.

The rated torque of a motor can be calculated using the following formula:

9550 x P

Mr = Rated torque (Nm) Pr = Rated motor power (kW) nr = Rated motor speed (rpm)

Slip-ring motors

In some cases when a D.O.L start is not permitted due to the high starting current, or when starting with a star-delta starter will give too low starting torque, a slip-ring motor is used. The motor is started by changing the rotor resistance and when speeding up the resistance is gradually removed until the rated speed is achieved and the motor is working at the equivalent rate of a standard squirrel-cage motor.

The advantage of a slip-ring motor is that the starting current will be lower and it is possible to adjust the starting torque up to the maximum torque.

In general, if a softstarter is going to be used for

this application you also need to replace the motor.

About Motors

Tst/Tn1.5...2.5

Torque diagram for a typical squirrel cage motor

rpm

Torque diagram for a slip-ring motor

rpm

Current diagram for a slip-ring motor

Different starting methods

The following is a short description of the most common starting methods for squirrel cage motors. An overview of common problems when starting and stopping a motor with different starting methods, see page 14

Direct-on-line start (D.O.L)

Different starting methods

Start-delta start

Frequency converter

Softstarter

Direct-on-line start (D.O.L)

This is by far the most common starting method available on the market. The starting equipment consists of only a main contactor and thermal or electronic overload relay. The disadvantage with this method is that it gives the highest possible starting current. A normal value is between 6 to 7 times the rated motor current but values of up to 9 or 10 times the rated current exist. Besides the starting current there also exists a current peak that can rise up to 14 times the rated current since the motor is not energised from the the first moment when starting.

The values are dependent on the design and size of the motor, but in general, a smaller motor gives higher values than a larger one.

During a direct-on-line start, the starting torque is also very high, and is higher than necessary for most applications. The torque is the same as the force, and an unnecessary high force gives unnecessary high stresses on couplings and the driven application. Naturally, there are cases where this starting method works perfectly and in some cases also the only starting method that works.

Different starting methods

D.O.L. starter with contactor and O/L relay

KM 1 Main contactor FR 1 Overload relay

KM 1

FR 1

Single line diagram for a D.O.L.

Starting torque

Torque/speed curve att D.O.L start

Current curve at D.O.L start

Max. starting current

Max. torque

Rated torque

rpm

Rated current

rpm

Star-delta start

This is a starting method that reduces the starting current and starting torque. The device normally consists of three contactors, an overload relay and a timer for setting the time in the star-position (starting position). The motor must be delta connected during a normal run, in order to be able to use this starting method.

The received starting current is about 30 % of the starting current during direct on line start and the starting torque is reduced to about 25 % of the torque available at a D.O.L start. This starting method only works when the application is light

Different starting methods

loaded during the start. If the motor is too heavily loaded, there will not be enough torque to

accelerate the motor up to speed before switching over to the delta position. When starting up pumps and fans for example, the load torque is low at the beginning of the start and increases with the square of the speed. When reaching approx. 80-85 % of the motor rated speed the load torque is equal to the motor torque and the acceleration ceases. To reach the rated speed, a switch over to delta position is necessary, and this will very often result in high transmission and current peaks. In some cases the current peak can reach a value that is even bigger than for a D.O.L start. Applications with a load torque higher than 50 % of the motor rated torque will not be able to start using the start-delta starter.

KM 2

KM 3 KM 1

400 V

Different starting methods

230 V

KM 1 Main contactor KM 2 Delta contactor KM 3 Star contactor FR 1 Overload relay

FR 1

KM 1

KM 3KM 2

Single line diagram for a Star-delta starterStar-delta starter with contactors and O/L relay

rpm

Torque/speed curve at Star-Delta start Current curve at Star-Delta start

rpm

Frequency converter

The frequency converter is sometimes also called VSD (Variable Speed Drive), VFD (Variable Frequency Drive) or simply Drives, which is probably the most common name.

The drive consists primarily of two parts, one which converts AC (50 or 60 Hz) to DC and the second part which converts the DC back to AC, but now with a variable frequency of 0-250 Hz. As the speed of the motor depends on the frequency this makes it possible to control the speed of the motor by changing the output frequency from the drive and this is a big advantage if there

Different starting methods

is a need for speed regulation during a continuous run.

In many applications a drive is still only used for starting and stopping the motor, despite the

fact that there is no need for speed regulation during a normal run. Of course this will create a need for much more expensive starting equipment than necessary. By controlling the frequency, the rated motor torque is available at a low speed and the starting current is low, between 1 and 1.5 times the rated motor current. Another available feature is softstop, which is very useful, for example when stopping pumps where the problem is water hammering in the pipe systems at direct stop. The softstop function is also useful when stopping conveyor belts from transporting fragile material that can be damaged when the belts stop too quickly. It is very common to install a filter together with the drive in order to reduce the levels of emission and harmonics generated.

KM 1 Main contactor Q 1 Frequency converter

Q 1

Frequency converter

KM 1

Single line diagram for a frequency converter

Softstarter

A softstarter has different characteristics to the other starting methods. It has thyristors in the main circuit, and the motor voltage is regulated with a printed circuit board. The softstarter makes use of the fact that when the motor voltage is low during start, the starting current and starting torque is also low. During the first part of the start the voltage to the motor is so low that it is only able to adjust the play between the gear wheels or stretching driving belts or chains etc. In other words, eliminating unnecessary jerks during the start.

Gradually, the voltage and the torque increase

so that the machinery starts to accelerate.

One of the benefits with this starting method is the possibility to adjust the torque to the exact need, whether the application is loaded or not. In principle the full starting torque is available, but with the big difference that the starting procedure is much more forgiving to the driven machinery, with lower maintenance costs as a result.

Another feature of the softstarter is the softstop function, which is very useful when stopping pumps where the problem is water hammering in the pipe system at direct stop as for star-delta starter and direct-on-line starter.

The softstop function can also be used when stopping conveyor belts to prevent material from damage when the belts stop too quickly.

Different starting methods

Softstarter

KM 1

FR 1

Q 1

KM 1 Main contactor FR 1 Overload relay Q 1 Softstarter

Single line diagram for a softstarter

Common problems when starting and stopping motors with different starting methods

Type of problem Type of starting method

Direct-on-line Star-delta start Drives Softstarter

Slipping belts and Yes Medium No No heavy wear on bearings

High inrush current Yes No No No

Heavy wear and tear Yes Yes No No

Different starting methods

on gear boxes (loaded start)

Damaged goods / Yes Yes No No products during stop

Water hammering in pipe Yes Yes Best Reduced system when stopping solution

Transmission peaks Yes Yes No No

Auto transformer start and start of a part winding motor have similar problems to the star-delta start.

Different applications

All motors are used for starting and running different applications. This chapter covers the most common ones. The different applications will also result in different load conditions for the motor. There are two factors to consider:

1. Braking load torque, a direct braking force on the motor shaft. To be able to accelerate, the motor has to be stronger than the load. The accelerating torque is the difference between the available motor torque and the load toque.

Accelerating torque = Available motor torque – load torque

2. Involved moment of inertia or flywheel mass will also affect the start. The bigger inertia the longer starting time for the same motor.

Available motor torque

Accelerating torque

Braking load (load torque)

rpm

Centrifugal fan

Centrifugal pump

Compressor

Conveyor belt

Different applications

Centrifugal fan

For some applications the motor is started with reduced load torque, i.e. unloaded start. Big centrifugal fans are often started with a closed damper and this will make the start easier (shorter) but since the moment of inertia is still present the starting time might be quite long anyway.

Direct-on-line start

Centrifugal fans are very often driven by one or more drive belts. During a D.O.L start these belts have a tendency to slip. The reason is that these

Different applications

types of fans always have a more or less high moment of inertia (big flywheel). So even if the fan is started unloaded, the flywheel is still there.

1616

rpm

Torque/speed curve at D.O.L start Current curve at D.O.L start

The belts slip depending on whether the starting torque from the motor is too high during the start sequence and the belts are not able to transfer these forces. This typical problem gives high maintenance costs but also production losses when you need to stop production to change belts and bearings.

rpm

Star-delta starter (Y-D)

The star-delta starter gives lower starting torque but depending on the fact that the load torque increases with the square of the speed, the motor torque will not be high enough in the star position to accelerate the fan to the rated speed.

When switching over to delta position it will be both a high transmission and current peak, often equal to values when making a D.O.L start or even higher, with a slipping belt as a result. It is possible to reduce the slip by stretching the belts very hard. This gives high mechanical stresses on bearings both in the motor and the fan with high maintenance costs as result.

Softstarter

Different applications

The key to solve these problems is to reduce the starting torque from the motor during start. By using an ABB softstarter the voltage is decreased to a low value at the beginning of the start, low enough to avoid slip but high enough to start up the fan. The softstarter provides the ability to adjust to fit any starting condition, both unloaded and fully loaded starts.

Torque/speed curve at Star-Delta start

Current curve at Star-Delta start

rpm

Torque/speed curve when using a softstarter

rpm

Current curve when using a softstarter

Selection of a suitable softstarter

Normal start

For fans with small or medium large flywheels, select a softstarter according to the rated motor power.

The above is valid if the time for D.O.L start

is less than 5 seconds.

Heavy duty start

For fans with large flywheels, select a softstarter

Different applications

designed for heavy duty start according to the rated motor power. It is also possible to select a softstarter for normal start, select a unit with one size bigger power rating than the motor and use an overload relay class 30.

The above is valid if the time for D.O.L start

is more than 5 seconds.

1818

Recommended basic settings:

Start ramp: 10 sec. Stop ramp: 0 sec. Initial voltage: 30 % Current limit is recommended for use.

Application with a centrifugal fan

Centrifugal pump

There are a lot of different types of pumps; like piston pumps, centrifugal pumps, screw pumps etc. But the most common version is the centrifugal pump and we have selected this one to describe.

Direct-on-line start

Starting up a pump is normally not a problem for a squirrel cage motor. The problem is the wear and tear depending on pressure waves in the pipe system created when the motor starts and stops too quickly. During a D.O.L start the motor gives much too high starting torque with the result that the motor accelerates and reaches nominal speed too quickly. The reason is that the braking load torque is low for a pump during start. This starting method also gives maximum possible starting current.

Different applications

Torque/speed curve at D.O.L start

rpm

Current curve at D.O.L start

Star-delta starter (Y-D)

When stopping a pump

By using a star-delta starter it is possible to reduce the starting torque. The motor torque in the star position is too weak to be able to complete the start and reach the rated speed.

The quadratic load torque will become too high for the motor when reaching approx. 80-85 % of the rated speed and the switch over to the delta position will give both high transmission and current peaks with pressure waves as a result.

Different applications

The current peaks can be equally high as at a D.O.L start or even higher.

During stop it is also normal to have problems. When making a direct stop by disconnecting the main supply the motor stops too quickly. Depending on high mass flow in the pipe system the water will continue with the same speed for a short period and then come back again, backwards in the pipe system. This creates high pressure shocks on valves and gives high mechanical stresses on the pipe system.

2020

rpm

Torque/speed curve at Star-Delta start Current curve at Star-Delta start

rpm

Softstarter

By using an ABB softstarter the voltage is reduced during the start sequence with the result that the motor torque is reduced. During the start sequence the softstarter increases the voltage so that the motor will be strong enough to accelerate the pump to the nominal speed without any torque or current peaks. A normal starting current with a softstarter when starting a fully loaded centrifugal pump is approx. 4 times rated motor current.

Also during the stop sequence the softstarter is the solution. The softstarter reduces the voltage during stop via a voltage ramp and the motor becomes weaker and weaker. Because of this the water speed slows down very smoothly without creating any pressure waves.

A special function on the softstarter is sometimes available, called "step-down voltage",which ensures an optimum setting to the actual need for any pipe system.

Different applications

rpm

Torque/speed curve when using a softstarter Current curve when using a softstarter

rpm

Selection of a suitable softstarter

Normal start

Starting a pump is a typical normal start condition. Select a softstarter according to the rated motor power.

Heavy duty start

Not applicable for this application.

Different applications

2222

Recommended basic settings:

Start ramp: 10 sec. Stop ramp: 20 sec. Initial voltage: 30 %

Application with a pump.

Compressor

Smaller compressors are often of piston type and the load torque increases linearly with the speed. Screw compressors are often used when there is a bigger need for air flow and this type has a load torque increasing with the square of the speed. Drive belts are often used between motor and compressor but direct connections via some type of toothed couplings are also common. Some compressors are started with reduced load.

Direct-on-line start (D.O.L)

Compressors started direct-on-line are exposed to high mechanical stresses on the compressor itself, but also on drive belts and couplings. The result is shortened endurance. In cases where the

drive belts are used the belts very often slip during start. The high starting torque received during starting with this method is the source of the problems. The starting current is always high at D.O.L start. A normal value can be approx. 7 times rated motor current.

Different applications

Torque/speed curve at D.O.L start

rpm

Current curve at D.O.L start

Star-delta starter (Y-D)

Star-delta start gives a lower starting torque and starting current but the motor is too weak during the start up to be able to accelerate the motor up to nominal speed. When switching to the delta position both current and torque peaks

Different applications

will occur with high mechanical stresses as a result. Compressors are very often running at no load condition for longer periods when the pressure in the system is high. A motor running under these circumstances always has a poor power factor and low efficiency. Some times the value is so low that it must be compensated.

2424

rpm

Torque/speed curve at Star-delta start Current curve at Star-delta start

rpm

Softstarter

By using an ABB softstarter it is possible to limit the starting torque to a level suitable for all different applications. The result is less stress on couplings, bearings and no slipping belts during start. The maintenance cost will be reduced to a minimum. When using a softstarter the starting current received is approx. 3 to 4 times the rated motor current.

Different applications

rpm

Torque/speed curve when using a softstarter Current curve when using a softstarter

rpm

Selection of a suitable softstarter

Normal start

For compressors with D.O.L starting time less than 5 seconds, select a softstarter according to the rated motor power.

Heavy duty start

For compressors with D.O.L starting time more than 5 seconds, select a softstarter designed for heavy duty start according to the rated motor

Different applications

power.

It is also possible to select a softstarter for normal start, select a unit with one size bigger power rating than the motor and use an overload relay class 30.

2626

Recommended basic settings:

Start ramp: 10 sec. Stop ramp: 0 sec. Initial voltage: 30 % (piston compressor)

40 % (screw compressor)

Application with a compressor

Conveyor belt

Conveyor belts can have a lot of different looks and directions of use. It is a typical constant torque load with low to high braking torque depending on how heavy it is loaded.

Direct-on-line start (D.O.L)

Conveyor belts often need a starting torque very near or just above the rated torque of the motor. A direct-on-line start with a normal squirrel cage motor gives approx. 1.5 to 2.5 times rated torque of the motor depending on motor size, type etc. When making a direct-on-line start there is a very high risk of slipping between the belt and

Low braking torque

the driving role depending on this high starting torque. Gearboxes and couplings are also exposed to high mechanical stresses. This result is considerable wear and tear and often high maintenance costs. Sometimes fluid couplings are used to reduce the transferred torque. This method is expensive and requires a lot of maintenance.

High braking torque

Different applications

Torque/speed curve at D.O.L start

Current curve at D.O.L start

rpm

Torque/speed curve at D.O.L start

rpm

Current curve at D.O.L start

Star-delta start

It is not possible to use this starting method when the load torque is close to the rated motor torque during start (see figure below, High braking torque).

Different applications

Low braking torque High braking torque

2828

rpm

Torque/speed curve at Star-delta start Torque/speed curve at Star-delta start

rpm

Current curve at Star-delta startCurrent curve at Star-delta start

rpm

Softstarter

Different applications

By using an ABB softstarter the starting torque can be reduced to a minimum value still able to start up the conveyor belt. The setting possibility of the softstarter makes it possible to adjust the torque to exactly the level that is necessary for the start. The result is the least possible stress on

rpm

Torque/speed curve when using a softstarter

gearboxes and couplings and no slipping belts during start. This will reduce the maintenance cost to a minimum. When using a softstarter you will receive approx. 3 to 4 times rated motor current during start.

High braking torqueLow braking torque

rpm

Torque/speed curve when using a softstarter

Current curve when using a softstarter

rpm

Current curve when using a softstarter

Selection of a suitable softstarter

Normal start

A start of short and light loaded conveyor belt is a typical normal start. For conveyors with D.O.L starting time less than 5 seconds, select a softstarter according to the rated motor power.

Heavy duty start

Conveyor belts can in some cases be very long and

Different applications

if the belt is fully loaded during start the starting time can be very long. For such applications select a softstarter designed for heavy duty start. It is also possible to select a softstarter for normal start if the softstarter is chosen one size larger than the rated motor power and use an overload relay class 30.

3030

Recommended basic settings:

Start ramp: 10 sec. Stop ramp: 0 sec. (If fragile material use 10 seconds) Initial voltage: 40 %

Application with a conveyor belt

How to select a softstarter for different applications

It is normally possible to select a softstarter according to the rated motor power. In some cases it is neccessary to select a larger softstarter than the rated motor power depending on the starting conditions (heavy duty start, many starts/h etc.) The starting capacity of a softstarter is very much depending on the thyristor capacity and the heat sink. The table below can be used as a guide to select a softstarter if you need a quick answer and you want to be sure that the size is large enough to suit the application. This selection will not give the most optimized solution. If an opimised solution is required, the software selection program ”ProSoft” for selection of softstarters can be used, available on www.abb.com/lowvoltage.

Quick guide

How to select a softstarter

Normal start

Typical applications

Bow thruster »Centrifugal pump

» »Compressor »Conveyor belt (short) »Elevator »Escalator

Selection

Select the softstarter according to the rated motor power.

For units with built-in overload, select trip class 10.

Select one size larger than the selection above.

If more than 6 starts /h

Heavy duty start

Typical applications

Centrifugal fan »Conveyor belt (long)

» »Crusher »Mill »Mixer »Stirrer

Selection

For softstarters designed for nomal start, select one size larger than the rated motor power.

For softstarters designed for heavy duty start, select according to the rated motor power.

For units with built-in overload, select trip class 30.

Description of the softstarters

- Design, settings and signals

A softstarter in general is built up with a few main components such as a printed circuit board (PCB), heat sink, thyristors, fans and housing (plastic or metal). The controlling circuits can be of digital type, analogue type or a combination of these. The output signal relays can be of a type with fixed function or as a free programmable type where the user can decide upon the output function.

The softstarter is sometimes equipped with a built-in electronic overload relay (EOL) replacing the conventional bi-metal relay which is normally used. A built in EOL has much better accuracy than a conventional relay, since the values are calculated electronically and this is especially useful when on intermittent duty.

The need for communication between different devices in a plant and from the devices to a control board is increasing all the time. Many of today’s softstarters are equipped with a port for such communication, which normally consists of a few fibre optic cables instead of former solutions, which often reqired hundreds of thousands of wires. Many different communication protocols exist today and some of them are more common than others, for example Modbus, Profibus, DeviceNet,

Interbus-S, LON Works and so on.

Description of the softstarter

Description of different components:

Housing

Printed circuit board

Description of components

Thyristor

Housing

Main terminals

Heat sink

Fan

Printed circuit board is used to

control the firing of the thyristors based on the current and voltage references, and also for the calculation of different values, for example the power factor, active power, etc. It can also be used for storing historical data, the event log, indicating trends and much more.

Heat sink is used to get rid of the heat in

the softstarter generated by the current during the start and the continuous run. The capacity of the heat sink very much reflects the starting capacity and the operational current of the softstarter.

Fans are used to increase the cooling

capacity of the heat sink. One, two or several fans can be used depending on size and design. Some smaller softstarters don’t have fans at all and the number of starts may be limited.

Zero crosses

Housing can be made of plastic material,

Description of components

metal or a combination of these, and its function is to protect the inside components from mechanical and electrical damage. It is also used to protect the components from dust and dirt. For total outside protection from dust and dirt a separate enclosure is often required since the degree of protection (IP class) of the unit itself is too low.

Thyristors are semi-conducting

components connected in an anti-parallel fasion and placed in two or three phases of the main circuit. They regulate (by increasing or decreasing) the level of voltage during start and the stop ramp, as described in the picture below. During a continuous run the thyristors are conducting fully.

Firing angle

Start: The thyristors let part of the voltage through at the beginning and then increase it, according to the set ramp time for the start.

Stop: The thyristors are fully conducting and when soft stopping, they decrease the voltage according to the set ramp time for stop.

Off : Thyristor is non-conducting On : Thyristor is conducting

Common settings

This section includes a short description of some common setting parameters available on most of the softstarters. Other settings may be available depending on the type of softstarter and manufacturer. The setting can be done either by adjusting potentiometers, changing dip switches, using a key pad, a computer or similar.

Start ramp is the time from were the

Common settings

softstarter start its ramp (initial voltage) until full voltage is reached. The ramp time should not be too long, as this will only result in unnecessary heating of the motor and a risk of the overload relay to trip. If the motor is unloaded the start time for the motor will probably become shorter than the set ramp time, and if the motor is heavily loaded, the start time will probably become longer.

Stop ramp is used when a soft stopping

of the motor is required, for example a pump or a conveyor belt. The stop ramp is the time from full voltage until stop voltage (initial voltage) is reached. If the ramp time is set to zero the stop will be like a direct stop.

Initial voltage

)

ini

Initial voltage. Sometimes named

pedestrian voltage or torque, this is the point from where the softstarter starts or stops its ramps. The torque of the motor will drop with the square of the voltage and if the voltage is set too low, for example 20 %, the starting torque will become 0.22 = 0.04 = 4 % only, and the motor will not start from the very beginning. Therefore it is very important to find a level that is just high enough to make the motor take off directly to avoid unnecessary heating.

Start ramp Stop ramp

Diagram showing start ramp, stop ramp and initial voltage

Time

Current limit can be used in applications

where a limited starting current is required, or at a heavy-duty start when it is difficult to achieve a perfect start with the setting of the initial voltage and the start ramp only. When the current limit is reached, the softstarter will temporarily stop increasing the voltage until the current drops below the set limit, and then continues ramping up to full voltage.

Note that this feature is not available on

all softstarters.

100 %

fixed voltage

30 %

Common settings

reached set level of current limit

t1 + t2 = set ramp time

Current limit function in softstarter use

set level of current limit

Time

Step down voltage gives a special

type of stop ramp. It is possible to adjust the voltage to drop to a level where the speed of the motor starts to reduce immediately at the stop command. For low loaded motors the speed will not reduce until a very low voltage is reached, but using the step down voltage function can eliminate this phenomenon and is especially useful for stopping pumps.

Common settings

Adjustable rated motor current makes it possible to set the motor

rated current on the softstarter for the used motor. This setting may affect other values as well, such as the trip level of the electronic overload relay, the level of the current limit function and so on.

Step down voltage = U

100 %

Example 50 %

30 %

Curve showing the step down voltage function

Initial voltage 30 % (= end voltage 30 %)

Stop Time

Different indications

The indications on a softstarter differ very much from one type to another and also between manufacturers. Some of the most common indications are described below.

Different indications

On normally indicates that the power supply

is connected to the softstarter and that the unit is ready to start the motor.

Top of Ramp indicates that the start

ramp is completed and full voltage is reached. If a by-pass contactor is used it will be activated at this point.

Fault indication can be of many different

types. One is if there is an internal fault on the softstarter itself, a fault on the feeding side (phase loss, blown fuse or similar) or on the motor side (motor not connected, phase missing etc.)

Overload indicates that the overload

protection has tripped. The reason for a tripping overload can be too high motor current, too long starting time, too many starts after each other, wrong set overload, wrong trip class of overload or a combination of these.

Overtemperature indicates that the

softstarter unit is over-heated, due to the number of starts exceeded, too high-rated current, too long starting time or similar.

Different voltages

Different named voltages are used for the softstarters. The name and use of these different voltages is stated in the IEC-standard as below.

Main Voltage (Ue),

which is the voltage feeding the motor and also the voltage exposed to the main circuit (thyristors) in the softstarter. 200 - 690 V

Different voltages

are normal values.

Supply voltage (Us),

which is the voltage feeding the electronic components inside the softstarter, for example the printed circuit board. Common values are 110 - 120 V or 220 - 240 V.

Internal supply

Main Voltage (Ue)

Start Stop

Power supply

Main voltage and supply voltage to a softstarter

Supply Voltage (Us)

Control Voltage (Uc),

which is the voltage for controlling the start and stop command of the softstarter. Values between 24 - 480 V exist.

Main Voltage (Ue)

Control Voltage (Uc)

Start

Stop

Power supply

(Internal power supply)

Main voltage and control voltage to a softstarter

Ambient temperature

The ambient temperature is the average surrounding temperature of the softstarter over a period of 24 hours. For most types of softstarter the temperature may not exceed 40 oC without derating the operational current for the unit.

The maximum ambient temperature during operation differs from one type of softstarter to another and must be checked individually according to the manufacturer’s specification.

When using an ABB softstarter with an ambient temperature of above 40 oC, the following formula can be used to calculate the operational current:

Ie derated = I

Ie derated = maximum operational current

- (∆ T x I

after derating

= rated current of the softstarter

x 0.008)

∆ T = temperature difference

0.008 = derating factor

Example 1

Rated current: 105 A Ambient temperature: 48 oC Derating with 0.8 % per oC above 40 oC (PS S 18...300)

∆ T = 48-40 New current = I 105 - (8 x 105 x 0.008) = 98,2 A

Example 2

Rated current: 300 A Ambient temperature: 46 oC Derating with 0.8 % per oC above 40 oC (PS S 18...300)

∆ T = 46-40 New current = I 300 - (6 x 300 x 0.008) = 285.6 A

C = 8 oC

- (∆ T x I

C = 6 oC

- (∆ T x I

x 0.008) =

Ambient temperature

Derating when used at high altitudes

When a softstarter is used at high altitudes the rated current for the unit has to be derated, due

High altitudes

to less cooling. For most manufacturers the catalogue values are valid up to 1000 m above sea level before derating is necessary.

In some cases a larger softstarter is required to be able to cope with the motor current when used at high altitudes.

For ABB softstarters the following formula can be used for calculating the derating:

x - 1000

% of I

100 %

90 %

150

% of Ie = 100 -

x = actual altitude for the softstarter

Example:

Softstarter with rated current 300 A used at 2500 meter above sea level.

1500

2500 - 1000

150

= 90

% of Ie = 100 -

= 100 -

150

Ie = 300 x 0.9 = 270 A

The diagram below can also be used for defining the derating of the softstarter.

80 %

1000

Derating of motor current at high altitudes

2000

meter above sea level

3000

4000 m

Start of several motors

In some applications, more than one motor will be started with one softstarter, in parallel with each other or in a sequence. This is often possible to do but some data has to be taken into consideration.

Parallel start of motors

If a softstarter is going to be used for starting several motors at the same time (parallel start), there are two important parameters to check:

1. The softstarter must be able to cope with the rated current for all motors together.

2. The softstarter must be able to cope with the starting current for all motors together until rated speed is achieved.

Note! If a by-pass contactor is used for the softstarter, only point 2 above has to be taken into consideration.

Example:

Start of two motors with I relative starting current 4 x Ie. Starting time is 10 seconds. Total starting current is 100 x 4 x 2 = 800 A over 10 seconds.

Check the softstarter starting capacity graph to verify the selected size.

= 100 A and

KM 1

FR 1

Q 1

Parallel start of motors using a softstarter

KM 1 Main contactor FR 1 Overload relay Q 1 Softstarter

Start of several motors

Sequential start of motors

If a softstarter is going to be used for starting several motors one by one (sequential start), it is important to check that the softstarter is able to cope with the starting current for each motor during the whole starting sequence.

Example:

Start of three motors with Ie=100 A and relative starting current 4 x Ie. Starting time for the motors is:

Start of several motors

Motor 1 = 5 seconds Motor 2 = 10 seconds Motor 3 = 8 seconds

The starting current for the motors is 100 x 4 = 400 A and the total starting time is 5 + 10 + 8 = 23 seconds.

Check the softstarter starting capacity graph to verify the selected size.

Note! It is not possible to add the starting time for each motor if the rated current is different from one motor to another. A separate calculation has to be made for those applications.

KM 1 Main contactor K 25, 27, 29 Starting contactor K 26, 26, 30 Run contactor FR 1, 2, 3 Overload relay Q 1 Softstarter

KM 1

Q 1

K 25 K 27 K 29

K 26

FR 1 FR 2 FR 3

Sequential start of motors using a softstarter

K 28 K 30

Different ways of connecting the softstarter

There are two different ways of connecting the softstarter - In line, which is the most common method, and Inside Delta. Note that only a few types of softstarters can actually be connected Inside Delta for example the ABB softstarter range PS S 18/30...300/515.

Different ways of connecting

In line Inside Delta

In-line connection

This is easily the most common way to connect the softstarter. All three phases are connected in a series with the overload relay, the main contactor and other devices used just like the diagram below. The selected devices for Inline connection must be chosen to cope with the rated motor current.

Example: 100 A motor requires a 100 A softstarter, 100 A main contactor etc.

Different ways of connecting

100 A

Inside Delta connection

The Inside Delta connection makes it possible to place the softstarter in the delta circuit and in that way it can easily replace an existing Y/D-starter.

When the softstarter is Inside Delta it will

only be exposed to 58 % (1/√3) of the In-line current. Therefore it is possible to downsize the devices in order to achieve a more cost-effective solution.

Example: A 100 A motor requires a 58 A softstarter, a 58 A main contactor if placed in the delta circuit, etc.

A motor used for an Inside Delta connection must be able to delta-connect during a continuous run. In the USA and some other countries a special six-wire motor has to be ordered for this type of connection.

100 A

Softstarter connected In-line with the motor

58 A

100 A

Softstarter connected Inside Delta

Location of the main contactor

When using the softstarter Inside Delta there are two options for the main contactor: in the delta circuit or outside. Both locations will stop the motor but in alternative A, the motor is still considered to be under tension. In alternative B the main contactor must be chosen according to the rated current of the motor, while the contactor in alternative A can be chosen according to 58 % (1/√3) of the rated current.

Different ways of connecting

Alternative A Main contactor located in the delta circuit

Alternative B Main contactor located outside the delta circuit

Basic settings

for

different

applications

The required settings for the softstarter will differ from one application to another depending on the type of load, motor characteristics, how much the motor is loaded, etc. For a more in depth description of each setting, please see chapter ”Description of the softstarters”.

Note ! All settings on next page are only proposals and may change from one application to another and therefore need to be checked individually.

Basic settings

Settings when using a softstarter without current limit function

Type of load Ramp time for Ramp time Initial voltage

Basic settings

Bow thruster 10 0 30 %

Centrifugal fan 10 0 30 %

Centrifugal pump 10 20 30 %

Centrifuge 10 0 40 %

Conveyor belt 10 0

Crusher 10 0 60 %

Escalator 10 0 30 %

Heat pump 10 20 30 %

Hydraulic pump 10 0 30 %

Lifting equipment 10 10 60 %

Mill 10 0 60 %

Piston compressor 10 0 30 %

Rotary converter 10 0 30 %

Scraper 10 10 40 %

Screw compressor 10 0 40 %

Screw conveyor 10 10 40 %

Stirrer, Mixer 10 0 60 %

Unloaded motor 10 0 30 %

start (sec.) for stop (sec.) U

ini

40 %

1) If fragile material, use 10 seconds.

Settings when using a softstarter with current limit function

Type of load Ramp time for Ramp time Initial voltage Current limit

start (sec.) for stop (sec.) Uini ( x Ie)

Bow thruster 10 0 30 % 3

Centrifugal fan 10 0 30 % 4

Centrifugal pump 10 20 30 % 3.5

Centrifuge 10 0 40 % 4.5

Conveyor belt 10 0

Crusher 10 0 60 % 5

Escalator 10 0 30 % 3.5

Heat pump 10 20 30 % 3.5

Hydraulic pump 10 0 30 % 3.5

Lifting equipment 10 10 60 % 4

Mill 10 0 60 % 5

Piston compressor 10 0 30 % 4

Rotary converter 10 0 30 % 3

Scraper 10 10 40 % 4.5

Screw compressor 10 0 40 % 4

Screw conveyor 10 10 40 % 4

Stirrer, Mixer 10 0 60 % 5

Unloaded motor 10 0 30 % 2.5

40 % 4

Basic settings

1) If fragile material, use 10 seconds.

Starting capacity and overload protection

Starting capacity for softstarters

When starting a squirrel cage motor there will

Starting capacity

always be a starting current (Ist) which is higher than the rated motor current.

The starting current depends on what type of starting method is used and in some cases also the size of the motor, particular at D.O.L-start. For a softstarter a normal value is 3-4 times the rated motor current.

Time

Sec.

1000

100

Heavy duty applications normally require a starting current between 4 and 5 times the rated motor current.

The maximum permitted starting current for a softstarter depends on the starting time. The ratio between the current and time is displayed in the graph below.

A higher starting current will give a shorter possible starting time, for example a crusher application. A lower current will allow a longer starting time, for example a pump application.

100

Typical starting capacty graph for a softstarter

200

300 400

Starting current

Starting capacity when using by-pass contactor

Starting capacity when using

Starting capacity

overload protection

When using a softstarter with a by-pass contactor it is sometimes possible to select a softstarter with a lower rated power than the motor rated power since the softstarter will be working during start and stop only, not continuously.

The softstarter can not withstand the rated motor current and therefore a check of the starting capacity must be carried out for the selected size.

Time

The overload protection for the motor (thermal or electronic) will very often set the limit of the starting capacity. A class 10 relay is used for normal starts in general while a class 30 relay is used for heavy-duty starts where a longer starting time must be used.

In some applications where the overload protection is by-passed (other protection active) during a start to achieve a longer available starting time, it is particularly important to check the softstarter starting capacity since this will be the limitation.

Starting

a) Tripping curve for overload protection b) Max starting capacity for a softstarter (This will limit the starting time / current if the overload is by-passed during start)

current

Number of starts/hour

The maximum number of starts/hour for a softstarter depends on several different factors such as the starting current, ambient temperature, starting time and the intermittens factor.

Intermittens factor

The intermittens factor is a figure indicating how long the softstarter has been running for (starting time and running time) compared with the total cycle time.

It is important to define the intermittens

Number of starts/hour

factor when talking about the number of starts/ hour since the OFF time is the cooling time for the softstarter.

A high starting current and a long starting time require a longer OFF time than a low starting current and short time to maintain the same number of starts/hour.

ntermittens factor =

Duty cycle

Examples:

If a softstarter has been running for 5 minutes of a total duty cycle of 10 minutes then the intermittens factor is 50 % ON time and 50 % OFF time.

If a softstarter has been running for 45 minutes of a duty cycle of 60 minutes then the intermittens factor is 75 % ON time and 25 % OFF time.

Off

on + off

x 100 %

Time

Harmonics

Harmonics are unwanted voltages and currents existing in almost every electrical system today and are always a multiple of the rated frequency. Typical harmonics are 3rd, 5th, 7th, 9th etc. The harmonics contribute to the unnecessary heating of motors, cables and other equipment and may shorten the lifetime of these devices if exposed for a long period of time.

It can sometimes also disturb functions on electronics and systems. The harmonic contents and the level naturally depends on the source but also on several other parameters such as the impedance in the feeding network, the motor, capacitors and other devices used in the system altogether - in other words a quite complex phenomenon.

Harmonic content and softstarters

The question of harmonic content for softstarter applications is actually in general not relevant at all. These reflections usually come from drive applications where harmonics are generated continuously and a filter is always required in public networks and very often used also in industrial networks. With our softstarters we fulfil the EMC directive concerning emission and immunity and there is no need for any particular actions regarding this matter at all.

Harmonics

Explosive atmospheres (Ex)

For plants in environments where the hazard of explosion is due to an explosive mixture of gases, explosive matter or combustible dust other than explosive dust, special provisions are applicable regarding the use of electrical material. For electrical motors there are two main principles for explosion protection. One is to design the motor so that no sparks or dangerous heat occurs. The other method is to isolate sparks and dangerous heat inside the motor to prevent ignition of any explosive mixture of gases outside the motor.

The different classes of explosive protection (Ex) are described by the following parts of IEC 60079:

Explosive atmospheres

IEC 600079-1: flameproof enclosures ”d” IEC 600079-2: pressurised enclosures ”p” IEC 600079-5: powder filling ”q” IEC 600079-6: oil immersion ”o” IEC 600079-7: increased safety ”e”

IEC 600079-11: intrinsic safety ”i” IEC 600079-18: encapsulation ”m” IEC 600079-22: caplights for mines susceptible to firedamp (under consideration)

Example: Electrical apparatus for explosive atmospheres - oil immersion ”o” shall be recognised as Exo.

Hazardous areas and zones

The hazardous areas are categorised in zones as follows:

Zone 0

An area in which an explosive gas atmosphere is present continuously or for long periods. Only intrinsically-safe circuits of category Exi may be used in this zone. Motors are thus excluded.

Zone 1

An area in which an explosive gas atmosphere is likely to occur in normal operation. Motors of category Exd, Exe and Exp may be used in this zone.

Zone 2

An area in which an explosive gas atmosphere is not likely to occur during normal operation and if it does occur it will exist for a short period only. Equipment permitted in zones 0 and 1 may of course be used. Under certain conditions the equipment, motors for instance, need not to be of explosion-protected design.

3 m

r4.5 m

Location and selection of softstarter for Ex environments

If a softstarter is going to be used for an Ex application it is normally located in a separate enclosure outside any of the hazardous zones. The overload relay used shall be of a special version designed for EEx motors, for example TA 25 DU...V 1000 to T 900 DU/SU...V 1000. This type of relay has a more accurate tripping curve compared with the standard relay. Special attention has to be paid to this.

The softstarter type and size and other devices used in the circuit shall suitably be selected according to type 2 co-ordination.

Note !

If any electrical equipment is going to be

used in any of the hazardous zones a special

enclosure must be used. This type of

enclosure (steel box or similar) must be

able to withstand an inside explosion

caused by any of the components without

letting anything out to the surroundings.

This solution is in general very unusual.

Explosive atmospheres

3 m

Low point

Zone 0

Example of classification and extent of the hazardous area in a tank

Zone 1

Zone 2

To wall

Surface of liquid

Height of wall

Co-ordination

By co-ordination we mean a selected combination of electrical apparatus which is safe for the surroundings and personnel, even if an overload or a fault should occur in the system.

The co-ordinated group must ensure the following four essential functions:

• Protection against overloads. A protection, which guards all components, cables

Co-ordination

and the motor from overheating, active for all currents up to, locked rotor current. This device will send a trip signal to a disconnection mean, which is normally a contactor used for the motor control.

• Motor control. This function is commonly carried out by a contactor.

• Protection against short-circuits, which takes care of all currents above the locked rotor current - i.e. all fault currents.

• Isolation. Ensure an isolating air-gap when opened for personnel safety.

The co-ordinations for the ABB softstarters are done according to IEC 60947-4-2 ”AC semiconductor motor controllers and starters” and EN 60947-4-2. The provisions of IEC 60947-1, General Rules, are applicable to IEC 60947-4-2 where specifically called for.

Types of co-ordination

The standard IEC 60947-4-2 defines two types of co-ordination according to the expected level of service continuity. The standard IEC 60947-1, General Rule are applicable to this standard, where specifically called for.

Type 1:

Co-ordination requires that, under short-circuit conditions, the device shall cause no danger to persons or installation and may not be suitable for further service without repair and replacement of parts.

Type 2:

Co-ordination requires that, under short-circuit conditions, the device shall cause no danger to persons or installation and shall be suitable for further use. For hybrid controllers and starters, the risk of contact welding is recognized, in which case the manufacturer shall indicate the measures to be taken as regards the maintenance of the equipment.

Note ! When using a softstarter in a type 2 co-ordination, replacing the fuses and restart has to be accepted after a shortcircuit. Only semi-conductor fuses can be used to achieve a type 2 co-ordination for a softstarter.

Co-ordination

Utilization Categories

Some utilization categories are stated in the standard IEC 60947-4-2, ”AC semiconductor motor controllers and starters”. The one used for ABB Low Voltage softstarters is AC-53.

Co-ordination

Utilization Typical application Category

AC-52a Control of slip-ring motor stators: 8 h duty with on-load currents for

start, acceleration, run

AC-52b Control of slip-ring motor stators: intermittent duty

AC-53a Control of squirrel cage motors: 8 h duty with on-load currents for

AC-53b Control of squirrel cage motors: intermittent duty

AC-58a Control of hermetic refrigerant compressor motors with automatic resetting of

AC-58b Control of hermetic refrigerant compressor motors with automatic resetting of

start, acceleration, run

overload releases: 8 h duty with on-load currents for start, acceleration, run

overload releases: intermittent duty

Remarks

AC-53 is the utilization category used for softstarters in general since this is about controlling squirrel cage motors. This is the category stated in the header of the co-ordination tables for softstarters.

AC-53a is about softstarter designed for use without by-pass contactor. AC-53b is about softstarter designed for use with by-pass contactor.

Types of fuses

There are basically three types of fuses used on the market (see below) with different functions and characteristics. One type of fuse cannot in general replace another type without checking the other protection devices in the circuit since the protection characteristic of the fuse is different between the types. If replacing a 100 A fuse with another 100 A fuse (same rating) without checking the type there is a risk of losing protection since the first type may be of type with both short-circuit protection and thermal protection while the replacement fuse is only short-circuit protection.

gL/gG fuses have a combination of short circuit protection and thermal overload protection (5s > 3,5 x In) for cables. If using these types of fuses together with a softstarter, type 1 co-ordination can be achieved. For type 2 co-ordination semi-conductor fuses must be used.

aM fuses have only a short-circuit protection (5s > 9 x In), and for thermal overload protection a separate protection device is required.

If using these types of fuses together with a

softstarter, type 1 co-ordination can be achieved. For type 2 co-ordination semi-conductor fuses must be used.

Semi-conductor fuses (High speed fuses) are the only type of fuses that are fast enough to achieve a fully type 2 co-ordination when using a softstarter. A separate overload relay for the motor protection is always required in combination with this type of fuse. If replacing the semi-conductor fuses with an MCCB, MMS or similar, type 1 co-ordination will be achieved instead.

Time

a: Characteristic of the overload relay b: Characteristic of a gL/gG fuse c: Characteristic of a semi-conductor fuse d: Area where the gL/gG fuse is not fast enough

to achieve a type 2 co-ordination

Current

Co-ordination

Where to find the co-ordination tables

The co-ordination tables for softstarters can be found on internet page www.abb.com under Low Voltage Products - Product Coordination. When selecting the wanted product type, for example softstarters the table below will show up.

Co-ordination

Ue Main voltage for the application

Iq Short-circuit current rating

Coor. Type Type of co-ordination

Starting type Type of start, normal or heavy duty

SCPD type Type of protection device

Size kW Rated motor power range

Table Name of the co-ordination table (click on the text to open)

Last Update Latest date of table update

Example of starter range, Ue= 400 - 500 V.

How to read the co-ordination tables

In the header of the selected table, information about softstarter type, main voltage, shortcircuit rating, maximum ambient temperature, IEC-standard and co-ordination type can be found.

Motor Indicates the rated output of the motor and maximum current.

If this does not correspond fully to the actual motor, select according to the maximum current.

Softstarter Indicates suitable softstarter type and size for this motor.

Semi-conductor fuses Indicates rated current and type of semi-conductor fuse.

Switch fuse Indicates suitable switch fuse for the semi-conductor fuses.

Thermal overload relay Indicates suitable thermal overload relay, type and setting range.

Co-ordination

Line contactor Indicates suitable line (main) contactor for the motor.

This contactor is given with AC-3 rating.

By-pass contactor Indicates suitable by-pass contactor which is not required for the

co-ordination. This contactor is given with AC-1 rating.

Example of co-ordination table: 500V, 65kA, normal start, type 2 (PSD5065LINE40)

Starter and fuses In-line Starter Inside Delta and

fuses In-line

The co-ordinations with the devices In-line are based on this circuit diagram.

Note that the by-pass contactor is not

Co-ordination

required for the co-ordination.

Softstarter

Switch fuse Semi-conductor fuse

Line contactor

O/L relay

By-pass contactor

The co-ordinations with the softstarter Inside Delta are based on this circuit diagram.

Note that the by-pass contactor is not required for the co-ordination.

Switch Fuse Semi-conductor fuse

Softstarter

By-pass contactor

Motor

Line contactor

O/L relay

Starter and fuses In-line Line contactor AC-3 By-pass contactor AC-1

Motor

Starter inside delta and fuses In-line Line contactor AC-3 By-pass contactor AC-1 Line contactor and by-pass contactor Inside Delta connected

ESD – Electro Static Discharge

An increasing problem today with the use of more and more electronic equipment in our systems is the Electro Static Discharge (ESD). The main source of the problem is the wrong handling of electronic components, printed circuit-boards, etc. A component damaged by ESD has been exposed to a too high voltage level and today the components are much more sensitive depending on integration, which means more functions in the same capsule. The distances between the conductors are decreased and therefore the insulation distance will be at a minimum. A value of 0.002 mm is common in modern integrated circuits.

Electro static charge is caused in three different ways:

• Rubbing of two surfaces to each other.

• Separation of two surfaces from each other, for example when removing a plastic cover from its contents.

• Induction caused by static electricity without any contact of the material.

Two type of faults and different circuits

The ESD damages are divided into two groups of faults: direct fault and latent defect. The direct faults are quite easy to detect since the component will not work at all and this is very often discovered at the factory before shipping.

The latent defects can be very difficult to identify since the component is not working in a reliable way and the life length of the device may be reduced dramatically.

Fault generated by ESD

Digital circuits:

• ”Ones” becomes ”zeros” and ”zeros” becomes ”ones” for no reason.

• No ”ones” or ”zeros” at all ( the circuit is dead).

Analogue circuits:

• Worsening accuracy of measuring

• Wrong voltage levels that require adjustments

• Malfunction

Printed Circuit Board (PCB)

ESD - Electro Static Discharge

Electro static voltage levels

A voltage level of between 100-500 V can destroy any electronic components in principle. The most sensitive components can only withstand voltages between 25-170 V.

Sometimes it is possible to hear a ”click” sound when touching an object and that is typical ESD phenomena. When it is possible to hear that ”click” sound the voltage level is already at least 3,5 kV. Sometimes it is also possible to see a spark when touching an object and the voltage level is then at least 10 kV.

Below some values are given for typical Electro static charge:

ESD - Electro Static Discharge

Walking on a wall-to-wall carpet: 10 - 20 kV

Walking on a plastic floor (PVC): 2 - 5 kV

Walking on an anti-static floor: 0 - 2 kV

Lifting paper from a table: 5 - 35 kV

Rising from a chair: 10 -25 kV

Protection against ESD damages

It is possible to reduce the risk of ESD to a minimum for the equipment. This is very important to remember when making service and/or repair with electronic components for example the printed circuit board on a softstarter.

Actions to prevent damages:

• Avoid charge if possible

• Always use a wrist strap or similar connected to ground potential when working with electrical components

• Always use the right type of package (ESD protected bags, etc.)

• Connect all machines and apparatus to ground potential

• High humidity

Frequently asked questions (FAQ)

Main contactor

Q Is there any requirement to put a main

contactor in series before the softstarter?

A The softstarter does not require any main

contactor but we recommend the use of one for emergency stop and/or trip of the overload relay. In some applications an MCCB can be used instead of the main contactor.

Ambient temperature

Q Can I use a softstarter if the ambient

temperature is higher than the recommended value during operation?

A The softstarter can normally be operated

at a higher ambient temperature during operation if the rated current for the unit is derated according to the manufacturer’s recommendation.

hyristor shorted

Q Is it possible to run a softstarter with one

thyristor shorted?

A Yes, it is possible but not for all types of

softstarters.

Soft stop applications

Q What applications are suitable for soft stop?

A Pumps and conveyor belts loaded with fragile

products are the two main applications suitable for soft stop.

Advantages of by-pass

Q What are the advantages of using by-pass?

A Reduction of power loss. It is also possible

to reduce the enclosure size and use a higher IP-class since air ventilation is not required.

Power loss

Q What is the power loss of a softstarter

during a continuous run?

A The values can normally be found in the

catalogue. For ABB softstarters the following formula can be used (for example for PS S 18...300): P

= [3 x Ie x 1.0] + 50 (W) reduced to

Ltot

50 W only which is the power of the cooling fans when using by-pass. Ie is the operational current of the motor.

Utilisation category

Q What utilisation category should be used for

the main contactor and the by-pass contactor?

A Main contactor: always use AC-3.

By-pass contactor: it is possible to use AC-1.

Fault indication when starting

Q Why does the softstarter indicate a fault

when the start signal is given to the main contactor and softstarter at the same time?

A If the main contactor is closed too late the

softstarter will indicate this as a phase loss fault. Delay the start signal to the soft starter by approx. 0.5 sec. to solve this phenomenon.

FAQ

Test without motor

Q Can I test a softstarter without using a motor?

FAQ

A No, this is not possible since there will be no

current going through the softstarter and some types will also indicate loss of load.

Different frequency

Q Can I use the same softstarter at both 50

and 60 Hz?

A It is possible with all type of ABB softstarters

as long as the curve is sinusoidal.

Overload relay trips during start

Q Why does the overload relay trip during start?

A Possible reasons can be one of these or in a

combination:

- too low current limit

- too long ramp time

- too low initial voltage

- wrong tripping class on the overload

- wrong setting on the overload

Separate overload relay when

using by-pass

Q Do I need a separate overload relay when

using a softstarter with built-in electronic overload and by-pass?

A If the current transformers of the softstarter

can be installed so that the measuring can be performed when by-passed a separate relay is not required; otherwise yes.

Voltage fluctuations

Q What voltage fluctuations are allowed for

the softstarters?

A The minimum and maximum value where

we can guarantee full function is -15 % to +10 % of the rated value. This is also stated in the IEC-standard.

Example: 400 V - 15 % to +10 % ≥ 340 V -

440 V range.

Semi-conductor fuses

Q Do I always have to use semi-conductor fuses?

A When using semi-conductor fuses a type 2

co-ordination can be achieved. It is possible to use an MCCB (moulded case circuit breaker) or MMS (manual motorstarter) instead but then with a type 1 co-ordination. For a more in-depth description see the chapter on co-ordination.

Environmental information

How a product affects the environment is a matter that is becoming more and more important when designing new products today but also when updating existing product ranges. In order to get a complete picture of all environmental aspects, there are some different methods of doing this.

LCA

LCA (Life Cycle Assessment) is a management tool for appraising and quantifying the entire life cycle of particular materials, the impact of products or activities over their total lifetime by analysing the entire life cycle of particular materials, processes, products, technologies, services or activities. The most important aspects affecting the environment for a softstarter has proven to be:

• Choice of material in the softstarter

• Energy losses during lifetime

• Recycling possibilities

The LCA process includes the entire lifecycle of a product

Environmental information

EPD

EPD (Environmental Product Declaration) is a document describing the environmental effects both during manufacturing and the usage of a specific product, for example the softstarter range PS S 18/30...300/515. The document includes among other things a material list indicating kg/product used of aluminium, copper, steel, glass, etc. and also tables for energy consumption

and losses. It is possible to see the difference when using the softstarter In-line, Inside Delta and/or with a by-pass contactor.

Tables for global warming potential, ozone depletion potential, acidification potential and so on are also included. The complete declaration is available on www.abb.com under document number 1SFC 288007-en.

Environmental information

Type of material kg/product kg/kW

Aluminium 2.2 0.03 Cardboard 2.4 0.03

Copper and copper alloys 3.1 0.04 Steel 4 0.05 Wood 0.83 0.01 Polymers 1.7 0.02 Epoxy resin 0.033 0.000 Glass 0.025 0.0003 Silicone rubber 0.0047 0.9*10

Example of a material list for a softstarter.

-4

Industrial IT

ABB has committed, as a key element of its business strategy, to a broad program of product development and positioning under the Industrial IT umbrella (IIT). The main reason behind the Industrial IT certification is to make it easier and more effective to combine products into systems and solutions.

All products that pass the Industrial IT certification tests achieve the Industrial IT

enabled sign.

Enabled products are verified for properties that make them work together in a pre-defined manner with other enabled products in an Industrial IT environment throughout the full life cycle of the plant. This means that IIT certified products should be easier to:

• Purchase

• Design

• Engineer

• Install

• Commission

• Operate

• Maintain

• De-install

Industrial IT

Different levels

In order to acknowledge the fact that there are different requirements on integration

properties between different applications and markets, there are four levels that a certain product can be certified for:

Industrial IT

Level 0 - Information

Level 3 - Optimisation

• Product is supplied with minimal aspect set in prescribed formats including Product Information, Product Classification, Product Documentation, CAD Data and Technical Data.

Level 1 - Connectivity

• As Information, plus.

• Hardware can be physically connected

via defined interfaces.

• Software is installed and handled in a consistent way.

• Basic interoperability of the product in the environment it is inserted in.

• Basic data can be exchanged via defined protocols.

Level 2 - Integration

• As Connectivity, plus.

• Aspect Object Types are provided with at least the Basic set of Aspects.

• Extended data can be exchanged via defined protocols.

• Relevant functionality is available as Aspect Systems on integration level 2.

• As Integration, plus.

• Aspect Object Types are provided with at least the Extended set of Aspects.

• Relevant functionality is available as Aspect Systems on integration level 3.

• The product is handled consistently throughout the life cycle and value chain.

Softstarter level

All our softstarter ranges today are Industrial IT enabled with the suite name Control Softstarters, certifiaction level 0 - Information.

An Industrial IT enabled product can be recognized by the Industrial IT enabled sign on the packing. More information and documentation is available on www.abb.com

Formula and conversion factors

In this chapter some useful formula and conversion factors can be found. The formulas can be used for calculating for example rated motor torque, moment of inertia, flywheel mass, etc. The conversion factors can be used to convert for example kW to HP, Celsius to Fahrenheit, km/h to miles/hour, etc.

Formula

Ohm’s law

I = UR =

Rated motor torque

Mr =

Moment of inertia

m(R

J =

Flywheel mass

9550 x P

+ r2)

or GD

U = I x R

(mD2 ~ GD2)

I = Current (ampere) U = Voltage (volt) R = Resistance (ohm)

Mr = Rated torque, Nm Pr = Rated motor power, kW nr = Rated motor speed, rpm

J = Moment of inertia, kgm m = Mass for the flywheel, kg R = Outer radius, m r = Inner radius, m

mD2 = Flywheel mass, kpm

= Flywheel mass, kgm

2 2

Formula and conversion factors

Relation Moment of inertia and Flywheel mass

J =

1 GD

1 mD

J = Moment of inertia, kgm mD2 = Flywheel mass, kpm

= Flywheel mass, kgm

Moment of inertia on load shaft recalculated to the motor shaft

x n

J´b =

Load torque on load shaft recalculated to the motor shaft

M´b =

Formula and conversion factors

Electrical power

J´b= Moment of inertia recalcu lated

to the motor shaft, kgm

Jb= Moment of inertia for the load,

kgm nb= Speed of the load, rpm nr= Speed of the motor, rpm

M´b = Load torque recalculated to the motor shaft, Nm Mb= Load torque, Nm nb= Speed of the load, rpm nr= Speed of the motor, rpm

U x I x PF

P =

1000

U x I x PF x √2

P =

1000

U x I x PF x √3

P =

1000

P = Power in kW (1-phase) PF = Power factor

P = Power in kW (2-phase)

P = Power in kW (3-phase)

Quantities and units

Length

yd. = yard m = metre mm = millimetre cm = centimetre in. = inch ft. = feet km = kilometre

Time

h = hour min = minute s = second

Weight

oz. = ounce lb. = pound kg = kilogram g = gram

Power / Energy

HP = horsepower W = watt kW = kilowatt kWh = kilowatt-hours

Volume

l = litre ml = millilitre cu.in. = cubic inch cu.ft. = cubic feet gal. = gallon fl.oz. = fluid ounce

Electrical

A = Ampere V = Volt W = Watt

Ω =Ohm

F = Farad

Formula and conversion factors

Conversion factors

Length

1 mile = 1,609344 km 1 km = 0,621 mile 1 yd = 0,9144 m 1 m = 1,09 yd 1 ft = 0,3048 m 1 m = 3,28 ft 1 in = 25,4 mm 1 mm = 0,039 in

Velocity

1 knot = 1,852 km/h 1 km/h = 0,540 knot 1 mile/h = 1,61 km/h 1 km/h = 0,622 mile/h 1 m/s = 3,6 km/h 1 km/h = 0,278 m/s

Area

1 acre = 0,405 ha 1 ha = 2,471 acre

Formula and conversion factors

1 ft 1 in

= 0,0929 m

= 6,45 cm

Volume

1 ft 1 in 1 gallon = 4,55 l (UK) 1 l = 0,220 gallon (UK) 1 gallon = 3,79 l (US) 1 l = 0,264 gallon (US) 1 pint = 0,568 l 1 l = 1,76 pint

= 0,0283 m

= 16,4 cm

Mass

1 lb = 0,454 kg 1 kg = 2,20 lb 1 oz = 28,3 g 1 g = 0,0352 oz

1 m 1 cm

= 10,8 ft = 0,155 in

= 35,3 ft = 0,0610 in

Moment of Inertia

1 Nm 1 kgm2= 0,2469 ft.-lb 1 oz.-in2= 0,000434 ft.-lb

Force

1 kp = 9,80665 N 1 N = 0,102 kp 1 lbf = 4,45 N 1 N = 0,225 lbf

Energy

1 kpm = 9,80665 J 1 J = 0,102 kpm 1 cal = 4,1868 J 1 J = 0,239 cal 1 kWh = 3,6 MJ 1 MJ = 0,278 kWh

Power

1 hp = 0,736 kW 1 kW = 1,36 hp 1 hp = 0,746 kW (UK,US) 1 kW = 1,34 hp (UK;US) 1 kcal/h = 1,16 W 1 W = 0,860 kcal/h

Temperature

0 oC = 32 oF o

C = 5 / 9 (oF-32)

0 oF = -17,8 oC o

F = 9 / 5 (oC+32)

= 2,42 ft.-lb

1 ft.-lb 1 ft.-lb 1 ft.-lb

= 0,41322 Nm

= 4,0537 kgm

= 2304,147 oz.-in

Formula and conversion factors

Glossary

AC Alternating current.

Ambient Temperature Ambient temperature is the temperature of water,

Glossary

Asynchronous speed The speed of an AC induction motor at full load

Bearing A component used to reduce the friction and wear

By-pass A by-pass contactor is used to by-pass another device,

CSA Canadian Standard Association

Current limit An electronic method to limit the starting current

Cycle A sequence of operations that is repeated regularly

air or surrounding medium where the equipment is used or stored.

and full voltage, also defined as the rated speed.

between rotating devices.

for example a softstarter to reduce the power loss.

to the motor during start up. It is normally possible to adjust the function so that the motor torque will be high enought to take off.

or the time it takes to complete one operation.

D-end The end that is normally the drive end of an electrical

motor.

DC Direct current

Degree of Protection Defined and stated as IP (International Protection)

class indicating the degree of protection against contact and penetration of solid objects and water.

Derating When a device has to be operated with reduced

ratings (normally the current) due to high ambient temperature or high altitude.

D.O.L Direct-on-line

Duty Cycle The total cycle from one start to the next, including

ramp time for start and stop, operation and pause time, if any.

Efficiency The ratio between mechanical output and electrical

input. The percentage given indicates how effective the motor is at converting electrical energy to mechanical energy.

EMF Electromotive Force, another term for voltage or

potential difference, for example the voltage generated by a motor.

EPD Environmental Product Declaration, a description

of how a specific product affects the environment.

ESD Electro Static Discharge.

Fault Any malfunction that occur and interferes with normal

operation.

Flywheel mass The total mass (mD2 or GD2) of a rotating body

normally given in kpm2 or kgm2. The value of the flywheel mass is 4 times the moment of inertia.

Frequency The number of periodic cycles per unit of time.

Gate The control element of an SCR (thyristor).

When giving a small positive voltage to the SCR it will start conducting.

Glossary

Heat Sink A component often made of aluminium used to get

rid of the heat inside an electrical device generated by the current.

Heavy Duty Start A start with a load that has a high or very high moment

of inertia. A starting time D.O.L. of more then 5 seconds can be defined as a heavy-duty start.

High load torque The braking torque on the motor shaft caused by

the load. If the braking torque is equal or nearly equal to the rated motor torque it can be defined as high load torque.

Glossary

IEC International Electrotechnical Commission which

is part of the International Standard Organisation.

Inertia A measure of a body’s resistance to change in velocity

whether the body is moving at a constant speed or is at rest. The velocity can be rotational or linear.

Induction motor An AC motor with a primary winding (usually the

stator) connected to the power supply and a secondary winding (usually the rotor) carrying the induced current.

In-Line connection A connection type where the devices in the main

supply are connected in series with each other.

Inside Delta connection A connection type where the devices are connected

inside the motor delta circuit. The current is reduced to 1/√3 = 58% compared to the line current.

Integrated Circuit (IC) A small electronic unit that can consist of thousands

of transistors usually mounted on a PCB.

Intermitens factor The relation between how long a machinery is

working (ON time) and how long it is resting (OFF time) in a cycle.

Jog Momentary moving of the motor by repetitive closure

of a circuit using a contact element or a pushbutton.

LCA Life Cycle Assessment, an analysis of how a product

affects the environment from ”cradle to grave”.

LCD Liquid Crystal Display, a readout interface used in

digital watches and laptop computers.

LED Light-emitting diode.

Locked Rotor Current The current taken from the line when a rotor is at

a standstill at rated voltage and frequency. It is the on line current when starting the motor direct.

Megger Test This is normally measured in megohms using full

voltage with low current and is used to measure the resistance in an insulation system. It can be used for checking the thyristors, for example.

Micro processor A central processing unit utilising large-scale

integration technology.

MCCB Moulded Case Circuit Breaker

MMS Manual Motor Starter

Glossary

N-end The end that is normally the non-drive end of an

electrical motor.

NEMA The National Electrical Manufacturers Association

(USA)

Network A number of nodes connected to each other with

some type of communication medium. A network can be of single link type or multiple link type.

Noise Unwanted disturbances in a communication medium

that tend to obscure the data content.

Normally Closed Contact A contact or set of contacts that are closed when (NC) the relay or switch is de-energised. The contact(s)

open when a relay or switch is energised.

Normally Open Contact A contact or set of contacts that are open when (NO) the relay or switch is de-energised. The contact(s)

close when the relay or switch is energised.

Normal Start A start with a load that has small or medium high

Glossary

Overload relay A device used to avoid overheating of the motor.

Parallel start Parallel start of motors is normally when two or more

PCB Printed Circuit Board.

PLC Programmable Logic Controller, consists of a central

Pow er Work done per unit of time measured in horsepower

Power Factor The phase difference measured between the voltage

moment of inertia. A starting time D.O.L. of less then 5 seconds can be defined as normal start.

Can be of electronic or thermal type.

motors are started at the same time with the same starting equipment.

processor, input/output interfaces and a memory designed as an industrial control system. A PLC system is used for the storage of instructions, timing, counting, report generation I/O control and more.

(HP) or watt (W).

and the current in an AC circuit represented by the cosine angle.

Protocol A set of conventions governing the format and timing

of data between communication devices.

Reversing Changing of the rotation direction of the rotor or

motor armature.

SCR Silicon Controlled Rectifier often referred to as a

thyristor.

Semi-conductor fuses A special type of high-speed fuse used as thyristor

protection since normal (gG/gL or aM) fuses are not fast enough.

Sequential start Sequential start of motors is normally when two or

more motors are started one by one in a sequence with the same starting equipment.

Serial Communication The way of transmitting data in a network

between different nodes, using some type of protocol.

Slip The difference (usually expressed in percentage)

between the synchronous speed and the rotor speed of an AC induction motor.

Star connection The connection type where each winding in a polyphase

circuit is connected at one end to a common point.

Synchronous speed The speed of the rotating magnetic field on an AC

induction motor determined by the frequency and the number of magnetic poles in each phase of the stator windings.

Thyristor A solid-state switch that has an anode, cathode and

a control element called the gate, which makes it possible to turn it on at will. It can rapidly switch large currents at high voltages.

Glossary

Tripping class The tripping class defines the starting time at a

specific current before tripping occurs. Different classes exist, for example 10, 20, 30 etc. where class 30 allows the longest starting time.

Torque A measure of the turning force ability for a device.

UL Underwrites Laboratories (an approval agency).

Y connection See Star connection.

Index

Accelerating torque 15

Index

Adjustable rated motor current 38 Ambient temperature 41

Braking load torque 15

CE Marking 1 Centrifugal fan. See Fan Centrifugal pump. See Pump Co-ordination 58, 59

table of 62, 63 Common problems, table of 14 Compressor 23

Suitable softstarter 26 Control voltage 40

Conveyor belt 27

Suitable softstarter 30 CSA specifications 1 Current limit 37

D-end 2 Delta connection 4 Direct-on-line start 9, 16, 19, 23, 27

Electro Static Discharge(ESD) 65, 66 Electronic overload relay (EOL) 33 Environmental Product Declaration

(EPD) 70

Explosive atmospheres (Ex) 56

Zone catergories 57

Fan 35

Suitable softstarter 18 FAQ - Softstarters 67 Fault 39 Firing angle 35 Formula and conversion factors 73 Frequency drive 12 Fuses 61, 64

Glossary 78

Harmonics 55 Heat sink 35 High altitudes, derating 42 Housing 35

In-line connection 46 Indications 39 Industrial IT 71, 72

Levels of certification 72 Initial voltage 36 Inside delta connection 46

Life Cycle Assessment (LCA) 69

Main voltage 40 Motors

about 2 calculations, speed 6 calculations, torque 7 mechanical overview 2 Parallel start 43 problems, start & stop 14 Sequential start 44 Slip-ring 7 Squirrel cage 3 Winding 4

Overload 39 Overload relay. See Electronic

overload relay (EOL)

Power factor 5 Printed Circuit Board (PCB) 35 Pump 19

stopping a pump 20 Suitable softstarter 22

Quick guide, softstarter applications

Settings 36

Adjustable rated motor current 38 Current limit 37 Initial voltage 36

Start ramp 36 Step down voltage 38 table, with current lim. 51 table, without current lim. 50

settings

Stop ramp 36

Softstarter 13, 17, 21, 25, 29

Component picture 34 How to select - Quickguide 31 Indications 39 Starting capacity 52

starts/hour 54 using by-pass contactor 53

using overload protection 53 Standards 1 Star-delta start 10 Star-delta starter 17, 20, 24, 28 Start connection 4 Start ramp 36 Starting capacity 52, 53 Step down voltage 38 Stop ramp 36 Supply voltage 40

Temperature, derating 41 Thyristor 35

UL specifications 1 Utilization Categories 60

Voltage 4 Voltage definitions 40

Index

ABB Automation Technology Products AB/Control, SE-721 61 Västerås, Sweden, Telephone +46 21 32 07 00, Telefax +46 21 12 60 01

Id.No 1SFC132002M0201 February 2003 ABB Automation Technology Products ABControl/XM Printed in February 2003/Edita Västra Aros

ABB Softstarters User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

Standards

About Motors

Different starting methods

Different applications

How to select a softstarter

Description of the softstarter

Common settings

Different indications

Different voltages

Ambient temperature

High altitudes

Start of several motors

Basic settings

Starting capacity

Number of starts/hour

Harmonics

Explosive atmospheres

Co-ordination

Environmental information

Industrial IT

Formula and conversion factors

Glossary

Index