MST Digital Soft Starter

www.baldor.com2

MST Digital

Soft Starter

MST Digital Soft StarterFrom the moment the first electrical motors were developed, engineers have been searching for ways to avoid electrical and mechanical stress caused by the starting and stopping of motors. Problems with direct-on-line (DOL) starting include high inrush current, voltage spikes, and excessive mechanical wear that can occur when motors start and stop. One traditional way to avoid this is to use a wye (aka “star”) delta starter, but this method is in many applications insufficient, as problems with current spikes and torque peaks remain. It also does not provide any way to perform a soft stop. The MST Digital Soft Starter, on the other hand, will provide far better performance during a start, as well as during a stop.

Baldor has been producing soft starters for over 25 years. All of the experience we have gained has been combined with today’s digital technology and incorporated into the MST Digital Soft Starter. Matching modern power electronics with smart circuitry and software, the Baldor MST Soft Starter offers superior control of current and voltage during motor start and stop. It also offers many new features that were unheard of in previous generations.

The Mechanical & Electrical Solution AC motors are the workhorse of industry. They are used for countless applications, including fans, crushers, agitators, pumps, and conveyors to name a few. Too often, unnecessary and unwanted torque and current spikes are an everyday occurrence in production plants all over the world, damaging electrical equipment and causing unnecessary wear on mechanical systems.

The results are:• Overloaded lines and unacceptable voltage variation due to

voltage and current transients from DOL and wye-delta starts. These transients can interfere with other equipment connected to the power system, from dimming of lights to computer failure

• Excessive mechanical wear across the entire drive chain, from motor to driven equipment, causing an increase in service and repair and causing unwanted down time

• Operational problems, such as damage to products conveyed from station to station

• For pump systems, water hammer and pressure surges put excessive loading in pipelines from starting and stopping the pumps

The financial consequences are considerable. Every technical problem and every breakdown costs money to diagnose and repair, not to mention the loss in production.

An economical and simple solution is to install a Baldor MST Digital Soft Starter. The Baldor MST Soft Starter provides smooth starting and stopping that minimizes mechanical and electrical stress on your equipment.

Motor voltage

100%

58%

70%

30%

Adjustable ramp slope

Time

DOL wye/delta Softstart

(1) The MST soft starter provides a more gradual acceleration.

Motor current

Motor speed

DOL

wye/delta

Softstart

(2) It lowers starting current and eliminates spikes.

Torque

Motor speed

DOL

wye/delta

Softstart

(3) The MST soft starter eliminates sudden and damaging changes in motor torque.

The MST Soft Starter compared to direct-on-line (DOL) and wye-delta (aka “star-delta”)

www.baldor.com 3

MST

Dig

ital

Soft

Star

ter

The Advanced SolutionThe MST Digital Soft Starter provides an advanced set of features including advanced protections, torque control, programmability and interface.

Advanced protections for not only the motor, but also the soft starter and the load ensure trouble-free operation. Pre-warnings detect problems before the motor needs to be stopped, which avoids unnecessary downtime.

The torque control function was developed and tested in collaboration with pump manufacturers to ensure the best possible stop without water hammer and pressure surges.

The full text LCD display shows what’s happening in plain English or other language. Preprogrammed application settings provide for fast and efficient setup. Fault logging assists with troubleshooting and diagnostics.

Other advanced features include:• Built-in bypass (370A and above)• Display and keypad• Adjustable current limit• Electronic motor overload protection• Thermistor (PTC) input for motor protection• Phase imbalance protection• Phase reversal protection• Locked rotor protection• Thyristor (SCR) overtemperature protection• Underload protection• Programmable warning functions• Analog output• Event logger• External keypad option

www.baldor.com4

MST Digital

Soft Starter

PumpsWater is the world’s most important resource and water facilities can be found all over the world. Examples of water applications are freshwater and wastewater systems, circulating water for heating or cooling and irrigation.

Industrial use • Process feed-water pumps • District heating pumps • Cooling water pumps • Slurry pumps

Drinking water distribution • Distribution pumps • Booster pumps

Irrigation • Intake pumps • Distribution pumps Water transmission

• Transfer pumps • Distribution pumps • Booster pumps

Desalination • Intake pumps • Brine pumps • Booster pumps • High pressure pumps • Drinking water pumps

Wastewater transportation • Influent and effluent pumps • Treatment pumps and fans

Water treatment • Treatment pumps

Effluent water • Effluent pumps

Effluent water • Effluent pumps

Waste incineration • Effluent pumps • Fans • Conveyors

Raw water intake • Raw water intake pumps

Raw water supply • Feed-water pump

Pumps:Q How are voltage drops avoided while starting?A Baldor MST Soft Starters will reduce the starting current, thus

avoiding the voltage drop

Q How is water hammer avoided while stopping?A Baldor MST Soft Starters use an optimized stop ramp and

control motor torque to eliminate water hammer

Q How does the MST Soft Starter protect the equipment?A Baldor MST Soft Starters are equipped with specially designed

protection algorithms to monitor overload, underload, and locked rotor conditions

www.baldor.com 5

MST

Dig

ital

Soft

Star

ter

ApplicationsFans

Compressors

Conveyors

Fans:Q How are extended voltage drops avoided during long starting

times?A Baldor MST Soft Starters are equipped with current limit to

keep control of the starting current

Q How is the life of the driving belts extended?A The Baldor MST Soft Starters reduce the mechanical stress

during start, thus avoiding belt slippage

Q How is the operation of the fan improved?A A Baldor MST Soft Starter with underload protection will detect

a broken belt immediately and alert the operator to the problem Compressors:Q How is compressor life extended?A Using a Baldor MST Soft Starter for starting will reduce the

accelerating torque, thereby minimizing the mechanical stress

Q How is the compactness of the compressor enhanced? A Using a compact Baldor MST Soft Starter will reduce the size of

starting equipment over a typical wye delta starter

Conveyors:Q How is service and repair of the conveyor belt or chain

reduced?A A Baldor MST Soft Starter will cause minimal mechanical stress

on the conveyor belt

Q How do you avoid running the conveyor belt in the wrong direction?

A Use a Baldor MST Soft Starter with phase reversal protection

Q How is efficiency of the conveyor belt improved?A Using the Baldor MST Soft Starter with high and low current

warnings allows you to adjust the load of the conveyor belt for optimal efficiency

Q How is starting ensured even when there is high starting resistance?

A A Baldor MST Soft Starter with kick start function will provide sufficient torque to be able to overcome the initial high friction from, for example, a temporarily jammed belt

Q How often do fast starting conveyors cause material spillage or pileup?

A Use Baldor MST Soft Starter to softly accelerate material handling conveyors

www.baldor.com6

MST Digital

Soft Starter

MST Digital Soft StarterDescription

Features• Wide range of operational voltage 208 – 575 V AC• Rated operational current 30 to 1040 A • Full text display and 4 button keypad for easy setup and

operation• Optional external keypad, IP66 (indoor)• Built-in bypass contactor (from 370 A) for energy savings and

reduced cooling needs• Ready for external bypass (30 – 300 A)• Torque Control for excellent control of pumps• Current limit, adjustable between 1.5 – 7 x Ie• Dual motor overload protection with NEMA Class 10 and Class 30• Adaptable motor underload protection to detect pumps running

dry or broken belt• Adaptable locked rotor protection • PTC thermistor protection to protect the motor from overheating• Adjustable kick-start to start jammed pumps or conveyors• Programmable output Form C relays• Programmable pre-warning functions• Event log with time stamp• Analog output showing current, voltage, power factor etc.

0 – 10 V, 0 – 20 mA, 4 – 20 mA

MST Digital Soft StarterBaldor continues a proud tradition of offering the very latest in motor control technology by introducing the MST digital soft starter with six SCR three phase voltage control.

Torque ControlThe torque control function was developed and tested in collaboration with pump manufacturers to ensure the best possible stop without water hammer and pressure surges.

Bypass for Energy SavingsBypassing the soft starter after reaching full voltage saves energy and reduces heat. The MST soft starters are equipped with extra terminals making the connection to an external bypass contactor easy, while allowing all protections to be active during bypass. Soft starters starting at 370 Amps have a built-in bypass contactor, ensuring a compact solution that simplifies installation.

Advanced ProtectionsThe MST soft starters are equipped with almost all protections imaginable for protecting the motor, the soft starter and the application. To offer more flexibility, protections can be tailored to specific needs.

Flexible Analog OutputThe analog output terminals can be connected to an analog current meter to show the current during operation, eliminating the need for an additional current transformer. The analog output can also be used as an analog input to a PLC or indicating/metering device.

Display and keypadThe MST soft starter is equipped with a full text display showing all information in clear text in English or many other languages. To make it even easier to set up, there are standard settings for many common applications such as a centrifugal pump, which will automatically configure the required settings including torque control when stopping.

External keypadAs an option, the MST soft starter can be equipped with an external keypad for easy setup and monitoring of the unit without opening the enclosure door. The keypad can also be used to copy parameters between different soft starters.

www.baldor.com 7

MST

Dig

ital

Soft

Star

ter

MST Digital Soft StarterDescriptionThe MST Soft Starter can be selected according to the rated motor power in normal duty for applications such as pumps, compressors, elevators, escalators, short conveyor belts and bow thrusters. Use heavy duty for applications such as centrifugal fans, crushers, mixers, mills, stirrers and long conveyor belts.

Keypad and DisplayGreen “Power On” LED

Red “Fault” LED

Yellow “Protection” LED

Full text display

User friendly keypad

Preset application settings

Enclosed Starter

Screw mounting

External keypad has same design as the fixed keypad

2 programmable inputs

3 programmable output signal relays

Built-in bypass on 370 Amp units and over

All data available on the front

Analog output or PTC input

Baldor enclosed combination starters have open starters mounted and wired in NEMA 12/4 packages. Each combination starter includes:

• bypass contactor for increased efficiency

• circuit breaker with door-mounted disconnect handle

• 2-wire control circuit

• space heater

• shunt trip

• Hand/Auto/Off selector switch

• indicator lights

Combination starters are available in Class 10 and Class 30 motor overload protection. Also available in a severe duty rating with manually energized bypass for emergency direct on line (DOL) starting.

www.baldor.com8

MST Digital

Soft Starter

MST Digital Soft StarterOpen Starters - Overview

MST-30-CA ... MST-72-CA MST-85-CA ... MST-142-CA

Soft Starter. Type

Normal start MST-30-CA MST-37-CA MST-44-CA MST-50-CA MST-72-CA MST-85-CA MST-105-CA MST-142-CA

Horsepower (460V) 20 25 30 40 50 60 75 100

UL Amps 28 34 42 54 68 80 104 130

Kilowatt (400 V) 15 18.5 22 25 37 45 55 75

IEC Amps 30 37 44 50 72 85 105 142

Max Power Loss (W) 100 120 140 160 230 270 325 435

with bypass (W) 10 11 14 14 17 31 35 37

Dimensions (h x w x d)

Inches 10.2 x 6.3 x 7.7 15.4 x 7.3 x 10.6

Millimeters 260 x 160 x 196 390 x 186 x 270

Weight 11 lb (5 kg) 29 lb (13 kg)

Using MCCB only, type 11) coordination will be achieved MCCB (10 kA, 480 - 600 V, 40 C)

Ts3 T4

Using J fuses, type 11) coordination will be achieved J type fuse protection (85 kA)

45 A 50 A 70 A 90 A 110 A 125 A 175 A 225 A

Fusible disconnect switch for the above J fuses Fusible disconnect switch

OS60 OS100 OS200 OS400

Line contactors are not required for the soft starter itself but often used to open if the Overload trips

Line contactor

AF30 AF50 AF75 AF95 AF110 AF145

Overload protection is used to protect the motor from over heating

Electronic overload relay

Built-in

Bypass contactors will reduce the power loss of the soft starter. All soft starters can be operated without bypass

Bypass contactor

AF16 AF26 AF30 AF50 AF75 AF110

1) In the event of short circuit Type 1 coordination assures no discharged part beyond the enclosure with soft starter, overload (and contacter) and internal parts damage is acceptable and may occur

www.baldor.com 9

MST

Dig

ital

Soft

Star

ter

MST Digital Soft StarterOpen Starters - Overview

MST-175-CA ... MST-300-CA MST-370 ... MST-470 MST-570-CA ... MST-1050-CA

Soft Starter. Type

Normal start MST-175-CA MST-210-CA MST-250-CA MST-300-CA MST-370-CA MST-470-CA MST-570-CA MST-720-CA MST-840-CA MST-1050-CA

Horsepower (460V) 125 150 200 250 300 400 500 600 700 900

UL Amps 156 192 248 302 361 480 590 720 840 1062

Kilowatt (400 V) 90 110.0 132 160 200 250 315 400 450 560

IEC Amps 175 210 250 300 370 470 570 720 840 1050

Max Power Loss (W) 540 645 765 920 - - - - - -

with bypass (W) 62 67 67 90 90 110 105 110 170 170

Dimensions (h x w x d)

Inches 16.5 x 14.2 x 10.6 18.1 x 14.4 x 14.2 20.3 x 17.2 x 15.0

Millimeters 420 x 360 x 270 460 x 366 x 361 515 x 436 x 381

Weight 51 lb (23 kg) 68 lb (31 kg) 132 lb (60 kg)

Using MCCB only, type 1 coordination will be achieved

MCCB (18 kA, 480 - 600 V, 40 C) MCCB (30 kA, 480 - 600 V, 40 C) MCCB (42 kA, 480 - 600 V, 40 C)

T4 T5 T6 T7 T8

Type J or L fuses, type 1 coordination will be achieved

J or L type fuse protection (85 kA)

250 A 300 A 400 A 500 A 600 A 800 A 1000 A 1200 A 1400 A 1800 A

Fusible disconnect switch for the above J fuses

Fusible disconnect switch

OS400 OS600 OS800 OS1200 - -

Line contactors are not required for the soft starter itself but often used to open if the Overload trips

Line contactor

AF185 AF210 AF260 AF300 AF400 AF580 AF750 AF1350 AF1650

Overload protection is used to protect the motor from over heating

Electronic overload relay

Built-in

Bypass contactors will reduce the power loss of the soft starter. All soft starters can be operated without bypass

Bypass contactor

AF145 AF185 AF210 Built-in

www.baldor.com10

MST Digital

Soft Starter

MST Digital Soft Starter – OpenRatings: Normal Starting – Class 10

Normal Starting - Class 10Agitator Chiller Large Pump

Axial blower Escalator Circular Saw

Axial Fan Low Inertia Fan Conveyor, Screw Feeder

Band Saw Propeller Fan Drill Press

Centrifugal Pump Small Pump

NOTE: If more than 10 starts per hour, select one size larger than the standard selection

MOTOR APPLICATION HORSEPOWER Soft StarterNormal Starting

UL Amps

IEC Amps

Catalog Number

SizeWeight

lbClass 10 - 400% torque for 30 seconds208V 230V 460V 575V7.5 10 20 25 28 30 MST-030-CA A 2

10 10 25 30 34 37 MST-037-CA A 2

10 15 30 40 42 44 MST-044-CA A 2

15 20 40 50 54 50 MST-050-CA A 2

20 25 50 60 68 72 MST-072-CA A 2

25 30 60 75 80 85 MST-085-CA B 5

30 40 75 100 104 105 MST-105-CA B 6

40 50 100 125 130 142 MST-142-CA B 6

50 60 125 150 156 175 MST-175-CA C 10

60 75 150 200 192 210 MST-210-CA C 10

75 100 200 250 248 250 MST-250-CA C 10

100 100 250 300 302 300 MST-300-CA C 10

125 150 300 350 361 370 MST-370-CA D 14

150 200 400 500 480 470 MST-470-CA D 14

200 250 500 600 590 570 MST-570-CA E 24

250 300 600 700 720 720 MST-720-CA E 25

300 350 700 800 840 840 MST-840-CA E 27

400 450 900 1000 1062 1050 MST-1050-CA E 27

Prosoft Sizing Software

These tables can be used to quickly select a suitable soft starter for most applications. If a more precise selection is required, or for diverse applications such as extreme heavy duty, use the Baldor Prosoft selection tool, available from www.Baldor.com.

www.baldor.com 11

MST

Dig

ital

Soft

Star

ter

MST Digital Soft Starter – OpenRatings: Heavy Starting – Class 30

Heavy Starting - Class 30Centrifugal Blower Loaded Screw Compressor Loaded Mixer

Centrifugal Fan Loaded Reciprocating Compressor Elevator

Chipper Pulverizer Positive Displacement Pump

Disintegrator Rock Crusher Reciprocating Compressor

Loaded Centrifuge Separator Vibrating Screen

NOTE: If more than 10 starts per hour, select one size larger than the standard selection

MOTOR APPLICATION HORSEPOWER Soft StarterHeavy Starting

UL Amps

IEC Amps

Catalog Number

SizeWeight

lbClass 30 - 350% torque for 60 seconds208V 230V 460V 575V

- - - - - 30 MST-030-CA A 2

7.5 10 20 25 28 37 MST-037-CA A 2

10 10 25 30 34 44 MST-044-CA A 2

10 15 30 40 42 50 MST-050-CA A 2

15 20 40 50 54 72 MST-072-CA A 2

20 25 50 60 68 85 MST-085-CA B 5

25 30 60 75 80 105 MST-105-CA B 6

30 40 75 100 104 142 MST-142-CA B 6

40 50 100 125 130 175 MST-175-CA C 10

50 60 125 150 156 210 MST-210-CA C 10

60 75 150 200 192 250 MST-250-CA C 10

75 100 200 250 248 300 MST-300-CA C 10

100 100 250 300 302 370 MST-370-CA D 14

125 150 300 350 361 470 MST-470-CA D 14

150 200 400 500 480 570 MST-570-CA E 24

200 250 500 600 590 720 MST-720-CA E 25

250 300 600 700 720 840 MST-840-CA E 27

300 350 700 800 840 1050 MST-1050-CA E 27

Soft Starter Simulator Software

Save time during installation by simulating the MST Soft Starter keypad interface on your PC. Practice setup. Simulate start, stop and fault events. Available at no charge from the Baldor Website, www.Baldor.com.

www.baldor.com12

MST Digital

Soft Starter

MST Digital Soft Starter - EnclosedCombination Starter with Circuit Breaker Disconnect

Enclosed NEMA Type 12/4 Combination Starter with Disconnect

MOTOR APPLICATION HORSEPOWER Soft Starter

Normal StartingUL

AmpsIEC

AmpsCatalog Number

SizeWeight

lbClass 10 - 400% torque for 30 seconds

208V 230V 460V 575V15 20 40 50 54 50 MST-050-GD A 7020 25 50 60 68 72 MST-072-GD A 7225 30 60 75 80 85 MST-085-GD B 10530 40 75 100 104 105 MST-105-GD B 11040 50 100 125 130 142 MST-142-GD B 11850 60 125 150 156 175 MST-175-GD C 21060 75 150 200 192 210 MST-210-GD C 22675 100 200 250 248 250 MST-250-GD C 230100 100 250 300 302 300 MST-300-GD C 240125 150 300 350 361 370 MST-370-GD D 343150 200 400 500 480 470 MST-470-GD D 352

Enclosed NEMA Type 12/4 Combination Starter with Circuit Breaker

MOTOR APPLICATION HORSEPOWER Soft Starter

Heavy StartingUL

AmpsIEC

AmpsCatalog Number

SizeWeight

lbClass 30 - 350% torque for 60 seconds

208V 230V 460V 575V15 20 40 50 54 72 MST-072-GD A 72- - - - - 85 MST-085-GD B 105

25 30 60 75 80 105 MST-105-GD B 11030 40 75 100 104 142 MST-142-GD B 11840 50 100 125 130 175 MST-175-GD C 21050 60 125 150 156 210 MST-210-GD C 22660 75 150 200 192 250 MST-250-GD C 23075 100 200 250 248 300 MST-300-GD C 240100 100 250 300 302 370 MST-370-GD D 343

- - - - - 470 MST-470-GD D 352150 200 400 500 480 470 MST-470-GD D 352

Severe Duty NEMA Type 4 Combination Starter with Circuit Breaker Disconnect

MOTOR APPLICATION HORSEPOWER Soft Starter

Heavy StartingUL

AmpsIEC

AmpsCatalog Number

SizeWeight

lbClass 30 - 350% torque for 60 seconds

208V 230V 460V 575V40 50 100 125 130 175 MST-175-GS C 22350 60 125 150 156 210 MST-210-GS C 22860 75 150 200 192 250 MST-250-GS C 23775 100 200 250 248 300 MST-300-GS C 244100 100 250 300 302 370 MST-370-GS D 373125 150 300 350 361 470 MST-470-GS D 399150 200 400 500 480 570 MST-570-GS E 649200 250 500 600 590 720 MST-720-GS E 681250 300 600 700 720 840 MST-840-GS E 687

www.baldor.com 13

MST

Dig

ital

Soft

Star

ter

MST Digital Soft StarterCombination Starter with Circuit Breaker Disconnect

MST Digital Soft StarterAccessories

External MOV

(Metal Oxide Varistor type voltage surge suppressor)

• Protect from line-to-line voltage spikes

• Recommended for all low line impedance applications

Remote Keypad with Cable

• 32 Character English alphanumeric display

• NEMA 4X indoor enclosure

• Backlit LCD

Catalog number Volts

MOV505L 460

MOV620EL 575

Catalog number Cable Length

MSTEK 10 ft.

Combination Starter DimensionsStandard (inches) Size H W D D1

MST-50 ...72 -GD A 20.0 20.0 12.8 14.6

MST-85 ...142 -GD B 24.0 24.0 12.8 14.6

MST-175...300 -GD C 36.0 36.0 12.8 14.5

MST-370... 470 -GD D 60.0 36.0 17.3 19.1

MST-570...840 -GD E 72.1 37.1 25.2 27.0

Metric (mm) Size H W D D1

MST-50 ...72 -GD A 508 508 325 370

MST-85 ...142 -GD B 610 610 325 370

MST-175...300 -GD C 914 914 325 369

MST-370... 470 -GD D 1524 914 439 485

MST-570...840 -GD E 1831 942 640 686See previous page for combination starter weight

SOLID STATE STARTER

H

W DD1

www.baldor.com14

MST Digital

Soft Starter

MST Digital Soft StarterSpecificationsRated insulation voltage Ui 690 V

Rated operational voltage Ue 208...600 V + 10 % / -15 % 50/60 Hz ±5%

Rated control supply voltage Us

100...250 V +10% / -15% 50/60 Hz ±5%

Rated control circuit voltage U

Internal or external 24 V DC

Starting capacity at Ie 4 x Ie for 10 sec.

Overload capability Class 10 and Class 30

Service factor MST-30...840 MST-1050

115 % 100 %

Ambient temperature

during operation ±0 ... +50 °C 1)

during storage -25 ... +70 °C

Maximum altitude 4000 m 2)

Degree of protection MST-30...72 MST-85...MST-1050

main circuit IP10 IP00

supply and control circuit IP20 IP20

Main circuit MST-30...300 MST-370...1050

Built-in Bypass contactor No Yes

Cooling system - Fan cooled Yes (thermostat controlled)

Keypad and display Full text

Languages English, German, Italian, Dutch, Chinese, Finnish, Swedish, French, Spanish, Russian, Portuguese, Turkish, Polish and Czech

Keys 2 selection keys and 2 navigating keys

Digital output Form C contact

Number of programmable signal relays

3 (each relay can be programmed to be Run, Bypass or Event signal)

K4 Default as Run signal

K5 Default as TOR (Bypass) signal

K6 Default as Event signal

Rated operational voltage, Ue 250 V AC / 24 V DC

Rated thermal current Ith 5 A

Rated operational current Ie at AC-15 (Ue=250 V)

1.5 A

Analog output

Output signal reference 0 ... 10 V, 0 ... 20 mA, 4 ... 20 mA

Type of output signal I Amp, U Volt, P kW, P hp, Q kVAr, S kVA, TmpMot, TmpSCR, cosPhi

1)Above 40°C up to max. 50°C reduce the rated current with 0.8% per deg. C

2)When used at high altitudes above 1000 meters up to 4000 meters, derate the rated current using the following formula:

[% of Ie = 100 - (x-1000)/150] where x = actual altitude of the soft starter

Control circuit

Number of inputs 2 (start, stop)

Number of additional programmable inputs

2 (Each input can be programmed to be either; Non, Reset, Enable, Jog, DOL- On, Start motor 2, Start motor 3 or FB-Dis)

Signaling indication LED

Power on Green

Fault Red

Protection Yellow

Protections

Electronic overload Yes (Class 10A, 10, 20, 30)

Dual overload Yes (separate overload function for start and run)

PTC connection Yes

Locked rotor protection Yes (Level and delay adjustable)

Underload protection Yes (Level and delay adjustable)

Phase imbalance Yes (Level and delay adjustable)

High current (8 x Ie ) Yes

Phase reversal protection Yes

Warnings (pre-warning)

High current Yes (Level and delay adjustable)

Low current (underload) Yes (Level and delay adjustable)

Overload trip Yes (Level and delay adjustable)

Overtemp, thyristor (SCR) Yes

Start of several motors

Possible to set up and start three different motors

Yes (Different parameter sets)

PTC Thermistor input

Switch off resistance 2825 ohm ± 20%

Switch on resistance 1200 ohm ± 20%

External keypad

Display LCD type

Ambient temperature

During operation ±0 ... +50 °C

During storage -25 ... +70 °C

Degree of protection IP66 (Indoor)

www.baldor.com 15

MST

Dig

ital

Soft

Star

ter

MST Digital Soft StarterTrip Curves for the Integrated Overload Protection

Class 30Class 20Class 10Class 10A

87654321

10 000

1000

100

10

1

00

Time (s)

Current (x Ie)

All units have an integrated electronic overload protection. It is possible to set it on four different tripping classes.

The chart below shows a curve for each tripping class from a cold state.

Tripping curves for electronic overload protection or MST Soft Starters from a cold state.

Contact your nearest Baldor Sales Office at these World Wide locations, or visit www.baldor.com

© Baldor Electric CompanyBR852

Printed in U.S.A.3/13 TCP 5000

Baldor Electric CompanyP.O. Box 2400

Fort Smith, AR 72902-2400 U.S.A.Ph (479) 646-4711 • Fax (479) 648-5792

International Fax (479) 648-5895www.baldor.com