PST300-600-70 300 A 208-600 V AC Soft Starter

The ABB PST300-600-70 is a Switch for industrial control and automation applications.

What is the ABB PST300-600-70 soft starter?

ABB PST300-600-70 is a soft starter rated 300 A for main circuits from 208 to 600 V AC. It limits inrush current during motor starting, reducing mechanical stress on driven equipment. This unit operates with a rated control supply voltage of 100 to 250 V AC at 50/60 Hz.

Key technical specifications

• Rated operational voltage: Main circuit 208 ... 600 V AC
• Rated operational current: 300 A in-line connection
• Rated control supply voltage: 100 ... 250 V AC
• Rated control circuit voltage: DC operation 24 V
• Current limit function: 1.5 ... 7xIe
• Ramp time: 0 ... 120 second
• Ambient air temperature: Operation 0 ... +50 °C
• Degree of protection: Main terminals IP00

How does This unit handle motor starting?

The soft starter provides an initial voltage during start of 30 to 70 percent. A step-down voltage special ramp of 100 to 30 percent is available. The current limit function adjusts from 1.5 to 7 times the rated operational current. Starting capacity reaches 3xIe for 15 seconds. These parameters allow precise matching to motor and load characteristics.

What protection and monitoring features are integrated?

Built-in electronic overload protection is standard. The service factor percentage is 115 percent. Four signal relays are provided: run, by-pass, fault, and overload. LED indication covers ready-to-start/standby (green), protection (yellow), and fault (red). Analog outputs include 0…10 volts, 0…20 mA, and 4…20 mA for external monitoring.

How is This unit installed and connected?

Main circuit terminals use bars with a hole diameter of 10.2 mm and width and thickness of 20x5 mm. Control circuit connections accept rigid 1 x 2.5 mm² or 2 x 1.5 mm². Supply circuit connections accept rigid 1 x 2.5 mm². Tightening torque is 0.5 N·m for control and supply circuits, and 28 N·m for the main circuit. The switch for inside delta connection enables higher power ratings: 257 kW at 400 V and 355 kW at 500 V, with a rated operational current of 515 A in inside delta connection. For in-line connection, rated operational power is 160 kW at 400 V and 200 kW at 500 V.

What are typical applications for this soft starter?

This unit suits pumps, fans, and compressors where controlled acceleration reduces wear. Its inside delta capability supports heavy-duty starting in water treatment and process industries. With a rated frequency of 50/60 Hz and ambient operating range of 0 ... +50 °C, it integrates into standard industrial environments. The FieldBusPlug standard communication interface allows system integration.

Why specify the ABB unit?

This soft starter combines a 300 A main circuit rating with flexible control options and built-in protection. Its analog outputs and signal relays provide verified status feedback. For engineering-grade precision in motor starting, This unit delivers exact parameter control. Contact AutoDCSTech with your exact requirements for precise matching.