Introduction

The ABB PST50-600-70 (1SFA894005R7000) is an advanced industrial soft starter designed to control the starting and stopping of three-phase asynchronous motors. As part of ABB's PST soft starter family, it combines controlled motor acceleration, adjustable current limiting, and integrated electronic overload protection.

With a 50 A in-line rated operational current and a main circuit voltage range of 208–600 V AC, this model is suitable for motor-driven equipment used in pumping systems, industrial ventilation, compressors, conveyors, and automated production machinery.

Unlike direct-on-line starting, which applies full voltage to the motor immediately, the PST50-600-70 gradually increases the motor voltage during startup. This helps reduce inrush current and sudden torque changes, protecting both electrical components and connected mechanical equipment.

Its adjustable motor-current settings and current-limit function provide flexibility when configuring the starter for different loads. The compact construction also makes it a practical choice for industrial control cabinets with limited installation space.

For machine builders, system integrators, and maintenance professionals, the ABB PST50-600-70 offers a dependable motor-starting solution for applications requiring controlled acceleration, integrated protection, and flexible configuration.

Technical Specifications

Parameter	Specification
Brand	ABB
Model	PST50-600-70
Order Number	1SFA894005R7000
Product Type	Soft Starter
Product Series	PST
Main Circuit Voltage	208–600 V AC
Control Supply Voltage	100–250 V AC
Control Circuit Voltage	24 V DC
Rated Operational Current (In-Line)	50 A
Rated Operational Current (Inside Delta)	85 A
Motor Power (In-Line, 400 V)	25 kW
Motor Power (In-Line, 500 V)	30 kW
Motor Power (Inside Delta, 400 V)	45 kW
Motor Power (Inside Delta, 500 V)	55 kW
Rated Frequency	50/60 Hz
Adjustable Motor Current	30–115% of Ie
Current Limit Range	1.5–7 × Ie
Starting Capacity	3 × Ie for 15 seconds
Motor Protection	Integrated Electronic Overload Protection
Connection Type	In-Line / Inside Delta
Dimensions	260 × 160 × 196 mm
Weight	4.8 kg / 10.58 lb

Recommended Related Models

The following ABB PST soft starters belong to the same product family and offer different current ratings for various motor-control requirements.

Model	Order Number	Product Type
PST30-600-70	1SFA894002R7000	Soft Starter
PST37-600-70	1SFA894003R7000	Soft Starter
PST44-600-70	1SFA894004R7000	Soft Starter
PST60-600-70	1SFA894006R7000	Soft Starter
PST72-600-70	1SFA894007R7000	Soft Starter

Popular Related Models

Other ABB PST soft starters that may be relevant to industrial motor-control projects include:

ABB PST85-600-70 Soft Starter
ABB PST105-600-70 Soft Starter
ABB PST142-600-70 Soft Starter
ABB PST175-600-70 Soft Starter
ABB PST210-600-70 Soft Starter
ABB PST250-600-70 Soft Starter
ABB PST300-600-70 Soft Starter
ABB PSTB370-600-70 Soft Starter

Applications

The ABB PST50-600-70 1SFA894005R7000 Soft Starter is designed for controlled starting and stopping of three-phase asynchronous motors in industrial applications. With a 50 A rated operational current for in-line connection, it helps reduce motor starting current and mechanical stress, supporting smoother operation and improved protection of connected equipment.

Typical applications include:

Water pump systems: Helps reduce pressure fluctuations during pump startup and stopping.
Industrial ventilation: Provides controlled acceleration for fans and blowers.
Air compressors: Helps minimize mechanical stress during motor starting.
Conveyor equipment: Supports smoother startup and reduces sudden torque changes.
Packaging machinery: Provides controlled motor operation in automated production lines.
HVAC systems: Supports reliable starting of compatible ventilation and air-conditioning motors.

Advantages and Key Features

1. Controlled Motor Starting

The PST50-600-70 gradually increases the voltage supplied to the motor during startup, helping limit high inrush current and reduce sudden mechanical torque.

2. Compact Design

Its compact construction makes it suitable for motor-control cabinets where installation space is limited.

3. Adjustable Starting Parameters

Configurable starting settings allow engineers to adapt motor acceleration to different load characteristics and application requirements.

4. Integrated Motor Protection

Electronic motor protection functions help monitor operating conditions and reduce the risk of damage caused by sustained overloads.

5. Flexible Connection Options

The PST series supports in-line and inside-delta motor connection arrangements, providing flexibility for compatible motor-control installations.

6. Wide Control Supply Range

The 100–250 V AC control supply range supports integration into different industrial control systems.

7. Simplified Motor-Control Design

By combining soft-start functionality and protection features in one device, the PST50-600-70 can help simplify control panel design and system integration.

Technical FAQs

Q1: What is the rated operational current of the ABB PST50-600-70?

The PST50-600-70 has a rated operational current of 50 A for in-line connection. For inside-delta connection, the maximum rated operational current is 85 A under the specified operating conditions.

Q2: What main circuit voltage does this soft starter support?

It supports a main circuit operating voltage range of 208–600 V AC, making it suitable for compatible three-phase motor applications.

Q3: What is the control supply voltage range?

The rated control supply voltage is 100–250 V AC at 50/60 Hz.

Q4: What is the rated motor power of the PST50-600-70?

For in-line connection, the rated motor power is 25 kW at 400 V and 30 kW at 500 V. For inside-delta connection, the corresponding ratings are 45 kW at 400 V and 55 kW at 500 V.

Q5: Does the PST50-600-70 support 24 V DC control?

Yes. The unit supports a 24 V DC control circuit, allowing integration into compatible industrial control systems.

Q6: Can the motor current setting be adjusted?

Yes. The adjustable rated motor current range is 30–115% of the soft starter's rated operational current. The setting should match the motor nameplate and the selected connection configuration.

Q7: What is the starting capacity of this model?

The PST50-600-70 supports a starting capacity of 3 × Ie for 15 seconds at the specified maximum rated current. Actual application suitability depends on motor characteristics and load conditions.

Q8: Does the soft starter provide current limiting?

Yes. Its current limit function can be adjusted within a range of 1.5–7 × Ie, helping users adapt the starting process to the electrical and mechanical requirements of the application.

Q9: What should be checked if the motor does not start?

Check the main power supply, control supply, start command, motor wiring, external interlocks, protection status, and configured motor parameters. Review any active fault indication before attempting another start.

Q10: Why might the PST50-600-70 trip during motor acceleration?

Possible causes include excessive load, incorrect motor-current settings, phase loss, abnormal supply conditions, or an unsuitable starting configuration. Check the fault indication and application conditions to identify the cause before restarting.

Look forward to your comments!Comment