ABB PST105-600-70 Replacement/Upgrade Solution for PST Series

Product Overview

ABB PST105-600-70 Replacement/Upgrade Solution for PST Series: Seamless Transition from Legacy Soft Starters

When your existing ABB PST105-600-70 soft starter reaches end-of-life, becomes obsolete, or fails unexpectedly on the production floor, a smooth and validated replacement is critical to minimizing unplanned downtime. The PST105-600-70 is a 105 A, 600 V, 70 kW three-phase soft starter from ABB’s PST/PSTB Series — a platform widely deployed in pump stations, compressor rooms, conveyor systems, fan arrays, and heavy industrial motor control centers (MCCs) across process industries worldwide. This page provides a structured upgrade and replacement guide for engineers and procurement teams managing the migration from legacy PST-series hardware to a fully compatible, tested, and warranted unit.

The PST105-600-70 integrates directly into existing MCC panels and motor control cabinets without requiring structural modifications. Its bypass contactor logic, 3-wire control wiring, and standard DIN-rail or panel-mount footprint are preserved in the replacement unit, allowing field technicians to complete a like-for-like swap in a single maintenance window. Whether you are replacing a failed unit, building a critical spare inventory, or executing a planned modernization of an aging drive system, TOPNLMS supplies tested PST105-600-70 units with full documentation support.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful PST105-600-70 replacement rarely involves the soft starter alone. In most industrial retrofit projects, the surrounding system components must be evaluated and, where necessary, upgraded in parallel to ensure reliable operation after commissioning.

The bypass contactor — typically an ABB AF series contactor rated at or above 105 A — must be verified for contact wear and coil voltage compatibility before the new soft starter is energized. In many aging MCCs, the main circuit breaker or motor protection relay, such as an ABB MS series motor starter or a SACE Tmax molded-case circuit breaker, may also require inspection or replacement to match the updated protection coordination curve of the new unit.

On the control side, if the existing system uses a hardwired relay logic panel, migration to the PST105-600-70 is straightforward: the 3-wire start/stop circuit, run signal output, and fault relay wiring are pin-compatible with the previous generation. However, if the plant is simultaneously upgrading its supervisory layer — for example, migrating from a legacy ABB AC500 PLC or an older Advant OCS controller to a current-generation ABB AC500-eCo or AC500-S Safety PLC — the digital output module driving the soft starter enable signal must be confirmed for 24 V DC or 110 V AC compatibility depending on the control circuit design.

For installations where the PST105-600-70 is integrated into a Profibus DP or DeviceNet network, the existing ABB NPBA-12 Profibus adapter or NDNA-02 DeviceNet adapter can be reused on the replacement unit, preserving all network node addresses and parameter mappings without requiring a full re-commissioning of the fieldbus segment. This is particularly valuable in large process plants where dozens of drives and soft starters share a single fieldbus ring.

In pump and HVAC applications, the replacement is often accompanied by an audit of the ABB NETA-21 remote monitoring gateway or the ABB Ability™ Smart Sensor attached to the motor, ensuring that condition monitoring data streams are re-established after the swap. Terminal blocks — such as Phoenix Contact or Weidmüller spring-clamp terminal strips already installed in the cabinet — typically require no changes, as the PST105-600-70 uses the same screw-terminal power and control connection layout as its predecessor.

Where the original installation used an ABB CP600 or CP400 HMI panel for local operator control, the replacement soft starter’s run/fault status outputs can be reconnected to the existing HMI I/O mapping without modifying the HMI project, provided the signal logic (normally open / normally closed) is verified against the original wiring diagram. Signal isolators or interposing relays, if present in the original design, should be retained to protect the new unit’s control inputs from voltage transients common in heavy industrial environments.

Retrofit Guidance FAQ

Q: Can I reuse the existing power wiring when replacing the PST105-600-70?
A: Yes. The PST105-600-70 uses standard L1/L2/L3 input and T1/T2/T3 output screw terminals. Provided the existing cable cross-section is rated for 105 A continuous and the cable insulation is in good condition, no rewiring is required. Verify torque values per the ABB installation manual.

Q: Do I need to re-enter all parameters after installing the replacement unit?
A: The PST105-600-70 parameters — including ramp-up time, ramp-down time, current limit, and kick-start settings — are set via the front-panel DIP switches and potentiometers. Document all existing settings before removal using a photograph or parameter record sheet. Re-enter the same values on the new unit before energizing.

Q: Is the replacement unit compatible with my existing Profibus or DeviceNet fieldbus adapter?
A: Yes. The NPBA-12 (Profibus DP) and NDNA-02 (DeviceNet) adapters mount to the same option slot on the PST105-600-70. The node address and baud rate settings stored in the adapter are retained, so no changes to the PLC program or fieldbus configuration are required.

Q: What is the physical installation space requirement?
A: The PST105-600-70 occupies the same panel footprint as the original unit. No cabinet modification, additional DIN rail space, or ventilation changes are required for a direct replacement. Ensure the existing thermal clearances above and below the unit are maintained per ABB specifications.

Q: How do I verify the replacement unit before installation?
A: Each unit supplied by TOPNLMS undergoes a pre-shipment functional test including insulation resistance check, control circuit continuity verification, and power-on self-test. A test report is available upon request. We recommend a bench test with a resistive load before installation in a live panel.

Q: What if my system uses 2-wire control instead of 3-wire?
A: The PST105-600-70 supports both 2-wire and 3-wire control modes, selectable via the control mode DIP switch. Confirm the existing wiring topology and set the switch accordingly before commissioning.

Warranty Assurance

Every ABB PST105-600-70 unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. This warranty covers manufacturing defects, component failures under normal operating conditions, and any functional non-conformance identified during incoming inspection at your facility.

Prior to dispatch, each unit is subject to a multi-point outgoing quality inspection: visual inspection for physical damage, terminal integrity check, control circuit power-on test, and verification of nameplate data against the order specification. Units that do not pass inspection are quarantined and not shipped.

In the event of a warranty claim, TOPNLMS provides a replacement unit or full refund within the warranty period. Our technical support team responds to warranty inquiries within 24 business hours. Replacement units for confirmed warranty cases are prioritized for next-available dispatch to minimize your system downtime.

For urgent replacement requirements — including same-day quotation, express air freight, and customs documentation support for cross-border shipments — contact our sales team directly. We maintain stock of PST-series soft starters and related ABB motor control components to support emergency procurement timelines.

TOPNLMS serves industrial buyers across manufacturing, oil & gas, water treatment, power generation, and building automation sectors. Our procurement team can assist with multi-unit orders, consignment stock arrangements, and approved vendor qualification documentation.