Industrial Applications

The ABB PST37-600-70 is an advanced soft starter designed to control the starting and stopping of three-phase AC motors. It belongs to ABB’s PST soft starter family and is intended for industrial applications where controlled motor acceleration, reduced starting stress, and dependable motor protection are important.

With a rated operational current of 37 A for in-line connection, this model is suitable for appropriately rated motors in pumping systems, ventilation equipment, compressors, conveyors, and general industrial machinery. Its main circuit supports operating voltages from 208 to 600 V AC, while the control supply operates within a range of 100–250 V AC.

Unlike a variable frequency drive, a soft starter primarily controls the motor voltage during starting and stopping. It is not designed to provide continuous variable-speed operation. Its purpose is to reduce the electrical and mechanical stress associated with direct-on-line starting.

1. Industrial Pumping Systems

Pumps can experience pressure fluctuations and mechanical stress when motors start or stop abruptly. The PST37-600-70 gradually increases motor voltage during startup, helping reduce sudden changes in pump operation.

It can be used in suitable water circulation, industrial fluid transfer, and auxiliary pumping applications. Correct ramp settings help match motor acceleration to the characteristics of the pump and pipeline.

2. Industrial Fans and Ventilation Equipment

Large fans may require substantial starting current and can impose mechanical stress on belts, shafts, and couplings. A soft starter provides a controlled acceleration process that can help reduce these effects.

The PST37-600-70 can be considered for compatible ventilation motors and industrial air-handling equipment where full variable-speed control is not required.

3. Air Compressors

Industrial compressors often operate under demanding starting conditions. Controlled motor acceleration can help reduce the electrical impact of starting and limit sudden mechanical loading.

The application must account for compressor unloading arrangements, starting frequency, motor current, and the manufacturer’s recommended starting method.

4. Conveyor Systems

Conveyors are widely used in manufacturing, packaging, and material-handling facilities. Sudden motor acceleration can cause belt movement, product displacement, and unnecessary stress on mechanical components.

The PST37-600-70 can provide controlled starting for compatible conveyor motors, helping machinery transition more smoothly into normal operation.

5. General Industrial Machinery

The soft starter can also be used with suitable mixers, processing equipment, and auxiliary machinery. Its application suitability depends on the motor’s rated current, starting torque requirements, load characteristics, and operating cycle.

Key Advantages

Controlled Motor Starting

The PST37-600-70 gradually increases motor voltage during startup. This helps reduce the abrupt electrical and mechanical effects associated with direct-on-line starting.

Reduced Mechanical Stress

Controlled acceleration can reduce sudden torque changes and mechanical shock. This is beneficial for equipment containing belts, couplings, gears, pumps, and other mechanical transmission components.

Integrated Electronic Motor Overload Protection

The PST37-600-70 includes electronic overload protection. Its adjustable rated motor current setting allows configuration according to the connected motor’s requirements.

The overload setting must be based on motor nameplate information and the applicable protection design.

Flexible Starting Parameters

The soft starter provides configurable starting and stopping parameters. Engineers can adjust the ramp settings to suit different load characteristics and process requirements.

Broad Main-Circuit Voltage Range

The model supports main-circuit operating voltages from 208 to 600 V AC, allowing it to be used in different industrial power systems when correctly selected.

In-Line and Inside Delta Installation

The PST37-600-70 supports both in-line and Inside Delta connection arrangements. Its current rating and applicable motor power rating differ depending on the selected connection method.

Industrial Panel Integration

Its compact dimensions of 260 × 160 × 196 mm allow installation in suitable industrial control cabinets. Appropriate ventilation, wiring space, and maintenance access must still be provided.

Technical FAQs

1. What is the ABB PST37-600-70?

The ABB PST37-600-70 is a three-phase AC motor soft starter from the PST series. It controls motor acceleration and stopping by regulating the voltage supplied to the motor during these operating stages.

2. What is the rated current of this model?

Its rated operational current is 37 A for in-line connection. When installed using an Inside Delta arrangement, the rated operational current is 64 A. The correct rating depends on the connection method and application requirements.

3. What is the operating voltage range?

The main circuit supports 208–600 V AC. The control supply voltage range is 100–250 V AC at 50/60 Hz.

4. What motor power can the PST37-600-70 support?

At 400 V, its published motor power rating is 18.5 kW for in-line connection and 30 kW for Inside Delta connection. At 500 V, the corresponding ratings are 22 kW and 37 kW. Actual selection must also consider motor current, load conditions, and starting duty.

5. Does this soft starter support Inside Delta wiring?

Yes. The PST37-600-70 supports Inside Delta installation. This arrangement requires the correct motor winding connections and suitable wiring design. The motor terminal configuration must be checked before installation.

6. Does the PST37-600-70 include overload protection?

Yes. It includes electronic motor overload protection. The rated motor current setting must be configured according to the connected motor and the system’s protection requirements.

7. Can this soft starter control motor speed continuously?

No. A soft starter is primarily designed to control motor starting and stopping. It does not provide the same continuous speed-control capability as a variable frequency drive.

8. What control supply does it require?

The rated control supply voltage is 100–250 V AC at 50/60 Hz. The control circuit also supports 24 V DC operation under the specified control-circuit configuration. Check the wiring documentation before applying control power.

9. What are the dimensions and weight?

The supplied dimensions are 260 × 160 × 196 mm, and the product weight is 4.8 kg. These values correspond to the manufacturer’s published product dimensions and net weight, with the dimensions arranged in a different order in some product records.

10. What should be checked before replacing an existing soft starter?

Check the complete model number, main voltage, rated current, motor power, connection method, control supply, control wiring, overload settings, and installation dimensions. A replacement should be selected according to the motor and application requirements rather than current rating alone.

Introduction

The ABB PST37-600-70 1SFA894003R7000 Soft Starter is designed to provide controlled starting and stopping for industrial three-phase AC motors. It helps manage the transition from standstill to normal operating speed, reducing the abrupt electrical and mechanical effects that can occur when a motor is started directly across the supply.

The PST series is intended for applications where conventional motor starters may produce excessive starting current or mechanical shock. By controlling the voltage applied to the motor during startup, the soft starter can help improve the starting characteristics of pumps, fans, compressors, conveyors, and other industrial machinery.

The PST37-600-70 has a 37 A rated operational current for in-line connection and a 64 A rating for Inside Delta connection. Its main-circuit voltage range is 208–600 V AC, while the control supply accepts 100–250 V AC at 50/60 Hz.

The model also incorporates electronic motor overload protection and configurable starting parameters. These functions allow engineers to adapt motor starting behavior to the characteristics of the connected equipment.

It is important to distinguish this product from a variable frequency drive. The PST37-600-70 is intended for controlled motor starting and stopping rather than continuous speed regulation. If a process requires frequent speed changes during normal operation, a suitably rated variable frequency drive may be more appropriate.

For maintenance and replacement projects, the full product identification number 1SFA894003R7000 should be checked against the installed unit. Connection method, motor ratings, control supply, and parameter settings should all be confirmed before commissioning.

Technical Specifications

Dimensions are expressed as height × width × depth. Confirm the installation drawing and terminal clearances before panel fabrication.

Function and Working Principle

The PST37-600-70 uses semiconductor-based voltage control to regulate the motor’s starting and stopping process. Instead of applying full supply voltage immediately, the soft starter increases the voltage gradually according to the configured starting parameters.

1. Controlled Voltage Ramp

When a start command is received, the soft starter controls the voltage supplied to the motor. The voltage increases progressively until the motor reaches normal operating conditions.

This process helps reduce the sudden current demand and torque changes associated with direct-on-line starting.

2. Adjustable Starting Time

The starting ramp can be configured to suit the connected motor and mechanical load. A pump, for example, may require a different starting profile from a conveyor or compressor.

The correct ramp time should be determined through commissioning rather than selected solely from the equipment’s nominal power rating.

3. Controlled Stopping

The soft starter can also provide a controlled stopping function. By reducing motor voltage according to the configured stopping profile, it can help reduce abrupt changes in certain applications.

The effectiveness of soft stopping depends on the motor and load characteristics. It should not be treated as a substitute for a mechanical brake or a safety-rated stopping system.

4. Electronic Overload Protection

The integrated electronic overload function monitors motor operating conditions and helps protect against sustained overload.

The rated motor current must be configured correctly. Incorrect settings can result in inadequate protection or unnecessary trips.

5. In-Line and Inside Delta Operation

The PST37-600-70 can be installed using either an in-line or an Inside Delta connection arrangement.

In-line installation places the soft starter in series with the motor supply. Inside Delta installation connects the soft starter within the motor winding circuit and requires a compatible six-terminal motor arrangement.

The current ratings differ between these arrangements. Wiring must follow the ABB installation instructions and the motor manufacturer’s connection diagram.

Installation and System Integration

Correct installation is essential for safe operation and reliable motor starting.

1. Verify Main-Circuit Voltage

Confirm that the incoming supply is within the 208–600 V AC operating range. Check the supply frequency and the motor’s voltage and current ratings before installation.

2. Select the Correct Connection Method

Determine whether the installation will use in-line or Inside Delta wiring. Confirm that the motor terminal configuration supports the selected arrangement.

Do not use the 64 A Inside Delta rating as an in-line rating. The applicable current and power values must match the actual wiring arrangement.

3. Configure the Control Supply

The control supply range is 100–250 V AC at 50/60 Hz. The control circuit also supports 24 V DC operation under the specified configuration.

Verify the terminal designations and wiring diagram before connecting the control supply.

4. Configure Motor Protection

Set the rated motor current according to the motor nameplate and the selected installation method. Review overload settings and other protection parameters during commissioning.

5. Provide Adequate Cabinet Ventilation

The product measures 260 × 160 × 196 mm and weighs 4.8 kg. Allow adequate space around the unit for airflow, wiring, inspection, and maintenance.

The installation environment should remain within the specified temperature and environmental limits.

6. Perform Functional Testing

After wiring, check the power and control connections, motor terminal configuration, grounding, and protection settings.

Test the start and stop commands under controlled conditions. Observe motor acceleration, current behavior, and any abnormal vibration or noise before placing the equipment into normal service.

Compatible System Components

Alternative Models and Replacement Considerations

When replacing the PST37-600-70, engineers should compare the electrical ratings, control supply, connection method, and starting requirements.

A replacement should not be selected based only on physical size or nominal motor power. Confirm current ratings, voltage range, starting duty, control supply, overload protection, connection arrangement, and terminal layout.

Procurement and Maintenance Recommendations

When purchasing the ABB PST37-600-70, verify both the model designation and order number: PST37-600-70 / 1SFA894003R7000.

For replacement projects, compare the nameplate details of the installed unit with the proposed spare. Check whether the application uses in-line or Inside Delta wiring, and confirm that the motor current falls within the applicable rating.

For used or surplus units, request clear photographs of the product label, terminals, and overall condition. Confirm whether the unit has been functionally tested and establish the applicable warranty and return terms.

During maintenance, inspect power terminals, control wiring, ventilation openings, and cabinet conditions. Review overload settings and operating history when investigating repeated trips or abnormal motor starting behavior.

Keep the original parameter settings and wiring documentation available. This helps reduce commissioning time when a soft starter is replaced.

Conclusion

The ABB PST37-600-70 1SFA894003R7000 is a 37 A industrial soft starter designed for controlled starting and stopping of three-phase AC motors. It supports main-circuit voltages from 208 to 600 V AC and offers both in-line and Inside Delta installation arrangements.

With integrated electronic overload protection and adjustable starting parameters, it is suitable for appropriately rated pumps, fans, compressors, conveyors, and other industrial machinery.

For installation and replacement work, engineers should verify the motor ratings, connection method, control supply, and protection settings. Correct selection and commissioning help maintain reliable motor operation and reduce unnecessary electrical and mechanical stress.