PSTB370-600-70 370 A 208...600 V AC Soft Starter

What the ABB PSTB370-600-70 Delivers in a 370 A Soft Starter

The ABB PSTB370-600-70 is a soft starter rated 370 A for a main circuit of 208 ... 600 V AC. Its control supply accepts 100 ... 250 V AC at 50/60 Hz, so the same unit can be commissioned on common industrial control voltages without an external transformer.

This model belongs to the PSTB370 series and carries product ID 1SFA894015R7000. The integrated electronic overload protection is built in, and the service factor percentage is 115 %. These features make the device a self-contained starting solution for large motors rather than a bare contactor with add-on protection.

Key Specifications and Starting Performance

The table below lists the verified electrical and mechanical parameters for this soft starter. Values are quoted exactly as published in the ABB data for this model.

• Rated operational current (in-line): 370 A
• Rated operational current (inside delta): 640 A
• Rated operational voltage: Main circuit 208 ... 600 V AC
• Rated control supply voltage: 100 ... 250 V AC
• Rated control circuit voltage: DC operation 24 V
• Rated frequency: 50/60 Hz
• Starting capacity: 3xIe for 15 s
• Current limit function: 1.5 ... 7xIe
• Ramp time: 0 ... 120 s
• Analog outputs: 0…10 volts, 0…20 mA, 4…20 mA

Inside-delta connection raises the usable current to 640 A and the rated operational power to 355 kW at 400 V or 450 kW at 500 V. In-line connection delivers 200 kW at 400 V and 257 kW at 500 V. Consequently, the connection method chosen at design stage directly determines the motor size the starter can support.

How Does This unit Handle Motor Starting?

The current limit function is adjustable from 1.5 to 7xIe, which lets engineers cap inrush current to match the supply capacity. Ramp times from 0 to 120 seconds and an initial voltage of 30 ... 70 % give controlled acceleration rather than a step start. A special step-down voltage ramp from 100 ... 30 % is also available.

Starting capacity is specified at 3xIe for 15 seconds, and the unit supports 10 starts per hour at 3.5xIe for 7 seconds with 50 % on time and 50 % off time. These figures matter on applications with frequent starts, because they define the thermal duty the starter can absorb.

Status Indication and Signal Relays

Four signal relays are provided: run, by-pass, fault and overload. Front-panel LEDs indicate ready-to-start or standby in green, protection in yellow, and fault in red. As a result, commissioning and fault-finding can be done at the panel without additional instrumentation. Analog outputs of 0…10 volts, 0…20 mA and 4…20 mA allow motor current or other values to be passed to a monitoring system.

Integration and Communication

A FieldBusPlug is fitted as standard, which provides the interface point for fieldbus communication. Wiring into a fieldbus network may require an external gateway or connection module. Confirm the correct cables and gateway for your network with AutoDCSTech before ordering.

The main circuit uses bar terminals with 10.5 mm hole diameter and 25x6 mm width and thickness, tightened to 35 N·m. Control and supply circuits accept rigid conductors of 1 x 2.5 mm² or 2 x 1.5 mm², tightened to 0.5 N·m. Main terminals are rated IP00 according to IEC 60529, IEC 60947-1 and EN 60529, so the starter must be mounted inside an enclosure.

Environmental Limits and Mechanical Data

The unit measures 366 mm wide, 460 mm high and 361 mm deep, with a net weight of 31 kg. Operating ambient temperature is 0 ... +50 °C, and storage range is -25 ... +70 °C. The package weighs 40 kg gross and measures 440 mm by 550 mm by 440 mm, which is relevant when planning panel space and lifting equipment.

Please verify current lifecycle status and availability with AutoDCSTech before ordering.