Product Overview
The GE PSTB720-600-70 is a heavy-duty softstarter designed for demanding industrial applications. This Industrial Automation Module handles motors up to 720 A (in-line) and 1247 A (inside delta), making it a robust choice for large pumps, fans, and conveyors. With a rated operational voltage of 208–600 V AC and a control supply of 100–250 V AC, it integrates seamlessly into existing systems.
Built for reliability, the PSTB720-600-70 includes built-in electronic overload protection, multiple signal relays (run, bypass, fault, overload), and an analog output for monitoring. Its compact footprint (436 mm width, 515 mm height, 381 mm depth) and 55 kg weight allow straightforward installation in standard enclosures.
Technical Specifications
| Parameter |
Value |
| Rated Operational Voltage |
Main Circuit 208 ... 600 V AC |
| Rated Control Supply Voltage (Us) |
100 ... 250 V AC |
| Rated Control Circuit Voltage (Uc) |
DC Operation 24 V |
| Rated Frequency (f) |
50/60 Hz |
| Rated Operational Power - In-Line (Pe) |
400 kW at 400 V; 500 kW at 500 V |
| Rated Operational Current - In-Line (Ie) |
720 A |
| Rated Operational Power - Inside Delta |
710 kW at 400 V; 880 kW at 500 V |
| Rated Operational Current - Inside Delta |
1247 A |
| Service Factor |
115% |
| Overload Protection |
Built-in electronic overload protection |
| Starting Capacity |
3xIe for 15s |
| Ramp Time |
0 ... 120 s |
| Initial Voltage During Start |
30 ... 70% |
| Current Limit Function |
1.5 ... 7xIe |
| Analog Outputs |
0–10 V, 0–20 mA, 4–20 mA |
| Degree of Protection |
IP00 (main terminals) |
| Ambient Temperature (Operation) |
0 ... +50 °C |
| Storage Temperature |
-25 ... +70 °C |
| Dimensions (W x H x D) |
436 x 515 x 381 mm |
| Net Weight |
55 kg |
Key Features & Benefits
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High Current Handling: Supports 720 A in-line and 1247 A inside delta, suitable for large motors.
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Flexible Control: Ramp time adjustable from 0 to 120 seconds; initial voltage from 30% to 70%.
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Built-in Protection: Electronic overload protection and current limit function (1.5–7xIe) safeguard the motor.
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Comprehensive Monitoring: Analog outputs (0–10 V, 0–20 mA, 4–20 mA) allow real-time data integration.
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Relay Outputs: Run, bypass, fault, and overload signal relays for status reporting.
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Easy Installation: Bar-type main terminals with 12.5 mm hole diameter and 40x6 mm busbar capacity.
Industry Applications
The GE PSTB720-600-70 excels in heavy-duty starting applications where inrush current must be controlled. Typical uses include:
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Pump Stations: Reduces mechanical stress on pumps and pipelines during start-up, extending equipment life.
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Centrifugal Fans: Provides smooth acceleration, preventing belt slippage and bearing wear.
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Conveyor Systems: Ensures controlled torque for loaded belt starting, minimizing product damage.
In each scenario, the softstarter's adjustable ramp time and current limit function deliver precise control, improving operational efficiency and reducing downtime.
Installation & Setup
Mount the PSTB720-600-70 on a flat, vertical surface using the provided mounting points. Ensure adequate clearance for ventilation, as the unit dissipates heat during operation. Connect the main circuit using copper bars that fit the 12.5 mm holes and 40x6 mm cross-section. For control wiring, use rigid conductors up to 2.5 mm² (single) or 1.5 mm² (double). Tighten control and supply terminals to 0.5 N·m, and main circuit terminals to 45 N·m.
Wire the control supply (100–250 V AC) and the 24 V DC control circuit as per the wiring diagram. Configure the ramp time and initial voltage using the front panel controls. Verify the LED indicators: green for ready/standby, yellow for protection, and red for fault.
Maintenance & Reliability
Regular inspection of the PSTB720-600-70 ensures long-term reliability. Check terminal tightness annually, as thermal cycling can loosen connections. Clean dust from the heatsink and enclosure to maintain proper airflow. The built-in electronic overload protection reduces the need for external relays, simplifying maintenance. With a service factor of 115%, the unit can handle occasional overloads without nuisance trips.
Operating in ambient temperatures up to +50 °C, the softstarter is designed for harsh industrial environments. Storage between -25 °C and +70 °C allows safe warehousing.
Compatibility & Integration
The PSTB720-600-70 supports a FieldBusPlug (standard) for communication, enabling integration with PLCs and SCADA systems. Analog outputs (0–10 V, 0–20 mA, 4–20 mA) provide real-time motor data for monitoring and control. The relay outputs can be wired to a control system for status indication or interlocking.
Selection Guide
Before purchasing, verify that the motor's full-load current does not exceed 720 A for in-line connection, or 1247 A for inside delta. Confirm the supply voltage matches 208–600 V AC and the control voltage is within 100–250 V AC. For applications requiring frequent starts, note the maximum of 10 starts per hour at 3.5xIe for 7 seconds (50% ON/OFF).
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