ABB SPAJ140C Replacement/Upgrade for REJ/SPAJ Series

Product Overview

ABB SPAJ140C Replacement/Upgrade Solution for REJ/SPAJ Series: Smooth Transition from Legacy Protection Systems

When aging protection relay infrastructure reaches end-of-life or a critical unit fails unexpectedly, the pressure to restore system integrity without extended downtime is immense. The ABB SPAJ140C over-current and earth-fault protection relay is a proven, field-tested solution that enables engineers and procurement teams to execute a seamless transition from legacy REJ and SPAJ series relays — preserving existing wiring schemes, panel layouts, and protection logic while delivering the reliability demanded by modern power distribution and industrial control environments.

The SPAJ140C belongs to ABB’s well-established SPAJ/REJ relay family, a platform widely deployed across utilities, substations, industrial plants, and critical infrastructure worldwide. Its modular architecture and standardized terminal configuration make it a direct functional replacement for a broad range of discontinued or aging protection relay models within the same series, including earlier SPAJ variants and compatible REJ-series units. Engineers migrating from older relay generations will find that the SPAJ140C’s terminal layout, auxiliary power input range, and output relay configuration align closely with predecessor models, significantly reducing rewiring effort and commissioning time during retrofit projects.

Compatibility Comparison Table

Seamless Upgrade Solutions: What You Need for a Complete Migration

A successful protection relay retrofit rarely involves a single component. When replacing the SPAJ140C or migrating from an older relay platform, the surrounding system infrastructure must be evaluated in parallel to ensure full compatibility and uninterrupted protection coverage.

In most substation and industrial panel installations, the SPAJ140C interfaces directly with current transformer (CT) secondary circuits. During migration, engineers should verify CT ratio and burden compatibility, particularly when upgrading from fixed 5A input relays to units supporting both 1A and 5A CT inputs. The SPAJ140C’s selectable input range eliminates the need to replace existing CTs in many retrofit scenarios, preserving significant installation cost.

Communication integration is another critical migration consideration. The SPAJ140C supports ABB’s SPA-bus protocol, which is compatible with existing SPA-bus master stations and SCADA gateways already deployed in REJ/SPAJ-based protection systems. For sites transitioning to IEC 60870-5-103 or LON-based communication architectures, the optional communication module for the SPAJ140C provides a direct upgrade path without requiring replacement of the entire protection panel. This is particularly valuable when the existing ABB REM543 or REM545 feeder protection terminals are being retained alongside the relay upgrade.

Panel wiring and terminal block compatibility are equally important. The SPAJ140C uses a standard rear screw-type terminal block that is physically compatible with most existing DIN-rail and 19-inch rack panel installations. In cases where the legacy relay used a draw-out cassette design, a simple terminal adapter plate resolves the mechanical interface without structural panel modification. Alongside the relay itself, procurement teams frequently source ABB SPTO 1D3 or SPTO 7D3 output relay modules, SPA-ZC 22 communication converters, and compatible test plugs to complete the panel retrofit kit.

For sites operating ABB MicroSCADA or Relion-series protection management systems, the SPAJ140C integrates cleanly into existing protection coordination schemes. Engineers migrating from older ABB SPAS 114 C or SPAS 120 C combined overcurrent and earth-fault relays will find the SPAJ140C’s protection characteristic curves and setting ranges directly comparable, enabling protection setting migration with minimal recalculation. The relay’s front-panel LED indicators, push-button test functions, and local/remote setting capability also reduce commissioning time during live panel changeovers.

Where the existing installation includes ABB SACO 16 D2 or SACO 25 D2 auxiliary contactors for trip circuit supervision, these remain fully compatible with the SPAJ140C’s output relay contacts, preserving the integrity of the trip circuit monitoring scheme without modification. Similarly, ABB SPTE 1E5 test switches and SPAJ series test plugs are directly reusable, further reducing the bill of materials for the retrofit.

All units supplied by TOPNLMS are individually tested prior to shipment. Stock is maintained in Xiamen, China, with standard international shipping timelines of 3–7 business days to most destinations. Expedited freight options are available for urgent plant maintenance requirements.

Retrofit Guidance FAQ

Q1: Can the SPAJ140C replace my existing SPAJ relay without rewiring the terminal block?
In the majority of REJ/SPAJ series installations, the SPAJ140C is a terminal-compatible replacement. The rear terminal block layout follows the standard SPAJ series pinout, meaning existing CT secondary wiring, auxiliary power connections, and output relay wiring can typically be reconnected directly. We recommend verifying the terminal diagram against your existing relay’s wiring schedule before installation, and we can provide the SPAJ140C terminal diagram upon request.

Q2: Is the SPA-bus communication protocol on the SPAJ140C compatible with my existing SCADA or protection management system?
Yes. The SPAJ140C uses ABB’s SPA-bus protocol, which is backward-compatible with all SPA-bus master stations and communication converters deployed in legacy REJ/SPAJ protection systems. If your site uses an SPA-ZC 22 or SPA-ZC 400 communication converter, no changes to the communication infrastructure are required. For sites migrating to IEC 60870-5-103, the optional communication module provides a direct upgrade path.

Q3: What physical space and panel cutout dimensions are required for installation?
The SPAJ140C is designed for standard 19-inch rack or flush-panel mounting, consistent with the REJ/SPAJ series form factor. The unit dimensions and panel cutout requirements are identical to most predecessor SPAJ models, making it a drop-in fit for existing panel openings. For draw-out cassette installations, a terminal adapter plate is required — please contact us for availability.

Q4: How are protection settings migrated from the old relay to the SPAJ140C?
The SPAJ140C uses the same IEC/ANSI overcurrent and earth-fault characteristic curves (IDMT, definite time) as predecessor SPAJ series relays. Existing protection settings — including pickup current, time multiplier, and instantaneous trip thresholds — can be directly transferred to the SPAJ140C’s setting ranges in most cases. Our technical team can assist with setting migration documentation upon request.

Warranty Assurance

Every ABB SPAJ140C unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. Prior to dispatch, each unit undergoes a pre-shipment functional test covering auxiliary power input, current input circuits, output relay operation, and front-panel indicator functions. Units that do not pass functional verification are not shipped.

In the event of a warranty claim, TOPNLMS provides a replacement unit or full refund within the warranty period. Our after-sales response time is within 24 hours for warranty inquiries. For urgent plant maintenance situations requiring immediate replacement, we maintain buffer stock of high-demand protection relay models including the SPAJ140C to support same-day or next-day dispatch.

Long-term supply continuity is a core commitment. As ABB’s SPAJ series transitions toward end-of-production, TOPNLMS maintains strategic inventory of SPAJ140C and related REJ/SPAJ series units to support customers through multi-year maintenance and retrofit programs. Blanket purchase orders and scheduled delivery arrangements are available for customers with ongoing replacement requirements.

For pricing, availability, technical documentation, or retrofit consultation, contact our industrial automation team directly.