ABB PST105-600-70 Soft Starter for PST Automation

ABB PST105-600-70 Soft Starter for PST Automation

The ABB PST105-600-70 is a high-performance soft starter engineered for demanding industrial motor control applications where energy efficiency, reduced mechanical stress, and optimized production line throughput are critical operational priorities. Rated at 105 A with a supply voltage range of 200–600 V and a control voltage of 110–120 / 220–240 V AC (70 V bypass), this unit belongs to ABB’s proven PST/PSTB Series of electronic soft starters — a platform trusted across compressor stations, pump systems, conveyor drives, and heavy-duty fan applications worldwide.

In modern industrial environments, uncontrolled motor starts are one of the leading causes of excessive energy consumption, premature bearing wear, and unplanned downtime. The PST105-600-70 addresses these challenges directly by delivering a controlled voltage ramp during motor start-up, limiting inrush current to a programmable threshold and eliminating the torque spikes that degrade mechanical couplings, gearboxes, and driven equipment. The result is a measurable reduction in peak demand charges, extended motor insulation life, and a smoother production line rhythm that supports consistent cycle times.

From an energy architecture perspective, the PST105-600-70 integrates naturally into layered automation systems. At the drive and control layer, it works alongside ABB’s ACS580 and ACS880 variable frequency drives where soft-start protection is required during bypass or direct-on-line transitions. For applications requiring coordinated multi-motor sequencing, the soft starter can be supervised by an ABB AC500 PLC (such as the PM573 or PM591 CPU modules), which handles start/stop interlocking, fault logging, and energy scheduling across production zones. The AC500’s CI867 PROFIBUS DP communication module enables real-time status feedback from the PST105-600-70, allowing the control system to monitor thermal state, current draw, and fault codes without additional wiring overhead.

Condition monitoring at the plant level is further enhanced when the PST105-600-70 is deployed alongside ABB’s M2BAX series IE3-rated induction motors, which are optimized for soft-start compatibility and deliver superior part-load efficiency. Pairing the soft starter with an ABB B23 or B24 energy meter at the motor control center (MCC) level provides granular kWh data per drive circuit, enabling facility managers to identify inefficient start cycles, benchmark energy consumption per production batch, and validate the ROI of soft-start retrofits against legacy direct-on-line starters.

At the human-machine interface layer, operators can visualize motor current profiles, start counts, and thermal overload margins through an ABB CP600 HMI panel, which supports trend logging and alarm management for the entire soft starter network. This visibility is essential for predictive maintenance workflows — by tracking the number of starts per hour and the thermal register value of the PST105-600-70, maintenance teams can schedule interventions before thermal trips occur, reducing unplanned downtime and keeping OEE targets on track.

For protection coordination, the PST105-600-70 is typically installed downstream of an ABB SACE Tmax XT series molded case circuit breaker, which provides short-circuit protection while the soft starter manages overload and phase-loss detection internally. In pump and compressor applications where motor protection relay functionality is required, the ABB UMC100 universal motor controller can be integrated to provide thermistor input monitoring, PTC protection, and fieldbus connectivity — complementing the soft starter’s built-in electronic overload protection and extending the overall protection envelope of the motor feeder.

The PST105-600-70 also supports sister units within the PST/PSTB family — including the PST72-600-70 and PST85-600-70 for lower-current applications, and the PSTB105-600-70 bypass-integrated variant for installations where continuous bypass operation is required after motor run-up. This product family consistency simplifies spare parts management, reduces technician training overhead, and enables standardized MCC designs across multi-site manufacturing operations.

Every PST105-600-70 unit supplied by ZYPLC undergoes pre-shipment functional testing, including insulation resistance verification, control circuit continuity checks, and operational simulation under rated conditions. Units are sourced from verified supply channels, inspected upon receipt, and covered by a warranty terms confirmed during quotation from the date of shipment. Stock availability is maintained to support urgent replacement requirements, with same-day quotation and rapid dispatch for availability confirmed by RFQ items.

Product Specification Table

System Compatibility and Application

Deploying the PST105-600-70 within a structured automation architecture unlocks compounding efficiency gains across the motor control, monitoring, and data feedback layers. At the field level, the soft starter interfaces directly with the motor terminal box of an ABB M2BAX IE3 motor, ensuring that the controlled voltage ramp is applied from the first electrical cycle of each start event. The ABB UMC100 motor controller sits upstream in the protection chain, providing thermistor monitoring and enabling remote reset via PROFIBUS — a capability that eliminates manual intervention for nuisance trips in unmanned pump stations.

At the control layer, the ABB AC500 PLC with a CI867 PROFIBUS DP module orchestrates start/stop sequences across multiple soft starters, enforcing staggered start logic to prevent simultaneous inrush events from multiple motors — a common cause of voltage sag and power quality issues in facilities with weak grid connections. The PLC’s energy scheduling function can also enforce off-peak start windows, directly reducing time-of-use electricity costs.

Power quality and consumption data are captured by ABB B24 energy meters installed at each MCC feeder, feeding real-time kWh, kVAR, and power factor data to the SCADA layer via Modbus TCP. This data stream enables the facility energy manager to correlate motor start frequency with energy cost per production unit — a key metric for ISO 50001 maintenance planning compliance. The ABB CP600 HMI provides the operator interface for alarm acknowledgment, start counter resets, and thermal overload margin visualization, while the ABB SACE Tmax XT MCCB upstream of each soft starter ensures coordinated fault clearance without nuisance tripping during controlled ramp-up events.

Maintenance and Replacement Notes

In a typical pump station application, replacing a direct-on-line starter with the PST105-600-70 reduces the starting current from 6–7× FLA to approximately 2–3× FLA, cutting the peak demand contribution of each motor start by up to 55%. Over a production year with multiple daily start cycles, this translates to measurable reductions in maximum demand charges — often the largest single line item on an industrial electricity bill.

On conveyor and crusher applications, the controlled torque ramp eliminates the mechanical shock loads that cause belt splice failures and gearbox oil seal leaks. Maintenance intervals for these components can be extended by 30–50% when soft-start control replaces DOL starting, directly reducing spare parts consumption and unplanned downtime hours. The PST105-600-70’s built-in electronic overload relay also eliminates the need for a separate bimetallic overload relay in the motor feeder, simplifying the MCC design and reducing panel wiring complexity.

For fan applications in HVAC and process ventilation systems, the soft starter’s adjustable stop ramp function prevents the water hammer and duct pressure surges that occur when large fans are de-energized abruptly. This feature alone can extend damper actuator and duct expansion joint service life significantly, contributing to lower facility maintenance costs and improved system availability. Combined with the predictive maintenance data available through the AC500 PLC and CP600 HMI, the PST105-600-70 supports a shift from reactive to condition-based maintenance — a transition that consistently delivers 15–25% reductions in total maintenance expenditure for motor-intensive production facilities.

Product Sourcing FAQ

Q1: How much energy can the ABB PST105-600-70 save compared to a direct-on-line starter?
The PST105-600-70 does not reduce energy consumption during steady-state motor running (a VFD is required for that). Its primary energy benefit is the reduction of peak demand charges by limiting inrush current during start-up, and the indirect operational stability from extended equipment life — fewer replacement cycles mean lower embodied energy consumption over the asset lifecycle. In facilities with demand-based tariffs, the reduction in peak kVA during motor starts can yield measurable monthly savings.

Q2: Is the PST105-600-70 compatible with my existing ABB ACS580 or ACS880 variable frequency drive system?
Yes. The PST105-600-70 is designed for applications where a soft starter is preferred over a VFD — typically fixed-speed loads such as pumps, compressors, and conveyors where speed variation is not required. It can coexist in the same MCC with ACS580 or ACS880 drives on adjacent feeders, and both can be supervised by the same ABB AC500 PLC via PROFIBUS DP or Modbus RTU.

Q3: What is the recommended replacement or upgrade path if my current soft starter has failed?
The PST105-600-70 is a direct form-fit-function replacement for earlier ABB PST series units of the same current rating. If upgrading from a non-ABB soft starter, verify control voltage compatibility (110–240 V AC) and bypass voltage (70 V) before installation. ZYPLC’s technical team can assist with cross-reference verification and provide pre-shipment testing confirmation for urgent replacement scenarios.

Q4: What does the warranty terms confirmed during quotation cover, and what is the testing process before shipment?
Every PST105-600-70 unit supplied by ZYPLC is tested prior to shipment, including control circuit function verification, insulation resistance measurement, and operational simulation. The warranty terms confirmed during quotation covers manufacturing defects and functional failures under normal operating conditions from the date of shipment. Units are sourced from verified supply channels and stored under controlled conditions to maintain component integrity.