Allen-Bradley 150-F85NBD Replacement for SMC Flex Series

Product Overview

Allen-Bradley 150-F85NBD Replacement for SMC Flex Series: Seamless Transition & Legacy System Upgrade

When your existing Allen-Bradley SMC Flex soft starter reaches end-of-life or becomes difficult to source, the 150-F85NBD stands as the proven drop-in replacement and upgrade solution for motor control centers, control panels, and distributed drive systems across manufacturing, water treatment, HVAC, and heavy industry. Engineered to deliver smooth motor ramp-up and ramp-down at 85A continuous current rating, this unit preserves your existing wiring topology, DeviceNet or hardwired control interface, and MCC bucket footprint — dramatically reducing retrofit engineering hours and unplanned downtime.

Many facilities running legacy Allen-Bradley SMC-2 (150-Axxx series) or SMC-3 (150-Cxxx series) soft starters face an urgent migration challenge: original units are discontinued, repair lead times stretch to weeks, and spare parts inventories are exhausted. The 150-F85NBD addresses this directly. Its DIN-rail and panel-mount compatibility, combined with standard three-phase line and load terminal layouts, means field technicians can complete a like-for-like swap within a planned maintenance window — often without modifying the existing conduit, cable tray, or terminal block wiring.

For sites integrating with a ControlLogix or CompactLogix PLC platform, the 150-F85NBD supports DeviceNet communication, allowing the existing RSLogix 5000 or Studio 5000 program to retain its Add-On Instructions and I/O mapping with minimal tag remapping. Where the legacy installation used hardwired start/stop and fault relay outputs, the unit’s onboard digital I/O terminals maintain backward compatibility with the control voltage levels and relay logic already present in the panel.

Compatibility Comparison Table

Seamless Upgrade Solutions

A successful migration from a legacy soft starter system to the 150-F85NBD typically involves more than a single component swap. In most MCC or standalone panel installations, the upgrade path also touches the bypass contactor — commonly a 100-C85D10 or 100-C72D10 IEC contactor from the Allen-Bradley 100-C series — which must be sized to match the 85A full-load current of the new starter. Where the original system used a 1492-CABLE series pre-wired cable assembly for I/O connections, these assemblies remain compatible with the SMC Flex’s terminal layout, preserving the structured wiring approach already in place.

Sites running DeviceNet networks will want to confirm that the 1788-EN2DN DeviceNet-to-EtherNet/IP linking device or the existing 1769-SDN DeviceNet scanner module in the CompactLogix rack is configured to recognize the 150-F85NBD’s EDS file. Uploading the correct EDS file via RSNetWorx for DeviceNet takes only minutes and ensures the PLC program can read motor current, fault codes, and operational status without rewriting ladder logic. For facilities that have already migrated their PLC backbone to a ControlLogix 1756 platform, the 1756-DNB DeviceNet bridge module provides the same seamless integration path.

In applications where the motor feeder circuit includes a 140M motor protection circuit breaker for upstream short-circuit protection, the existing breaker coordination study remains valid — the 150-F85NBD’s inrush limiting function actually reduces the peak current demand during starting, which can extend the service life of both the breaker and the motor windings. Where signal isolation is required between the soft starter’s analog output (motor current 4–20 mA) and the plant DCS or SCADA system, a DIN-rail mounted signal isolator or a 1734-IE2C POINT I/O analog input module can bridge the interface without additional engineering.

For facilities managing a broader motor control modernization project, the 150-F85NBD integrates naturally alongside PowerFlex 525 or PowerFlex 755 variable frequency drives on the same DeviceNet or EtherNet/IP network segment, allowing a mixed soft-starter and VFD architecture to be managed from a single Studio 5000 project. This is particularly valuable in pump stations or compressor rooms where some loads require soft starting and others require variable speed control.

Retrofit Guidance FAQ

Q: Can I reuse the existing three-phase power wiring from my SMC-2 or SMC-3 installation?
A: In most cases, yes. The 150-F85NBD uses standard L1/L2/L3 line terminals and T1/T2/T3 load terminals in the same relative positions as earlier SMC series units. Verify cable lug sizing against the 85A terminal torque specification in the installation manual before re-terminating.

Q: Do I need to rewrite my PLC program after replacing the soft starter?
A: If your existing program uses the SMC Flex EDS file and DeviceNet node address, no ladder logic changes are required — only a node address verification and EDS re-registration in RSNetWorx. For hardwired installations, no program changes are needed at all.

Q: Will the 150-F85NBD fit in the same MCC bucket or panel cutout as my old unit?
A: The SMC Flex series shares the same panel depth and mounting hole pattern as most SMC-3 frame sizes at the 85A rating. Measure the existing cutout against the 150-F85NBD dimensional drawing (available on request) before ordering if your panel has non-standard spacing.

Q: What communication protocols does the 150-F85NBD support?
A: The unit natively supports DeviceNet. It does not natively support EtherNet/IP or Modbus RTU without an external gateway. If your new control architecture requires EtherNet/IP, a 1788-EN2DN linking device provides the protocol bridge.

Q: How do I handle the bypass contactor during the upgrade?
A: The bypass contactor must be rated at or above the motor full-load current (85A in this case). If the existing contactor is undersized or worn, replace it concurrently with the soft starter to avoid nuisance tripping after commissioning.

Q: What protection functions does the 150-F85NBD add over my legacy SMC-2?
A: The SMC Flex adds phase-loss detection, motor jam protection, stall detection, and ground fault indication — functions not available on the basic SMC-2 platform. These can be enabled or disabled via the onboard keypad to match your existing fault management philosophy.

Warranty Assurance

Every 150-F85NBD unit shipped by TOPNLMS carries a 12-month warranty covering manufacturing defects and functional failures under normal operating conditions. Prior to dispatch, each unit undergoes a pre-shipment functional test including power-on verification, control terminal continuity check, and communication port validation. Units are packed in anti-static, shock-absorbing packaging suitable for international air and sea freight.

In the event of a warranty claim, TOPNLMS provides a replacement unit dispatch within 3 business days of fault confirmation, with return freight covered for verified defective units. Our technical support team — reachable at [email protected] or +86 18359293191 — can assist with installation questions, parameter configuration, and commissioning guidance throughout the warranty period and beyond.

Stock is maintained in Xiamen, China, with express DHL/FedEx shipping available to most destinations worldwide. Lead time for in-stock units is typically 3–7 business days door-to-door for international orders. Bulk procurement inquiries and OEM pricing are welcome.