Product Overview

The ABB SPAJ140C is a high-performance, integrated protection solution designed to safeguard power distribution networks against overcurrent and neutral-to-earth faults. Operating as a secondary relay interfaced with current transformers, this multifunctional device provides continuous surveillance of phase and neutral currents. It is engineered to perform high-speed fault isolation, alarm signaling, and comprehensive fault recording within a single, ruggedized chassis. By consolidating two major protection functions into one unit, the SPAJ140C streamlines panel wiring and improves system reliability. Whether deployed in industrial plants or utility substations, this relay ensures critical assets are protected with millisecond-level precision during transient or sustained fault conditions.

Core Protection Parameters and Hardware Data

• Protection Stages Dual low-set (I> / I0>) and high-set (I>> / I0>>) units

• Response Speed ~40 ms for high-set stages; ~60 ms for low-set stages

• Time-Current Curve Support Definite time and IDMT (Normal, Very, Extremely, Long-time Inverse, RI, and RXIDG curves)

• Standard Compliance BS 142 and IEC 60255 international protection standards

• Input Interface Specialized current transformer (CT) secondary inputs

• Control Logic Integrated binary inputs for remote setting group changes and stage blocking

• Network Integration Ethernet router service compatible for diagnostic reporting

• Hardware Mass 3.2 kg

• Casing Dimensions 24 x 13.2 x 16 cm

• Manufacturing Origin Sweden

• Export Tariff Code 8537101190

Industrial Protection Applications

The SPAJ140C is a versatile component found in complex electrical infrastructures where coordinated tripping is mandatory:

• Feeder Protection Monitoring radial distribution lines to prevent damage from downstream faults and localized earth leakages.

• Large Motor Protection Providing secondary overcurrent defense for high-voltage industrial motors in refineries and mining operations.

• Substation Automation Managing auto-reclosing sequences and signaling for remote circuit breaker control.

• Transformer Protection Safeguarding primary and secondary windings from sustained overloads and neutral-path insulation failures.

• Redundant Protection Logic Utilizing the binary inputs to block specific stages in coordination with other system-wide relays to prevent unnecessary outages.

Q: What curve options are available for the IDMT functions in the SPAJ140C?

A: The relay supports six distinct curves: standard Normal, Very, Extremely, and Long-time inverse curves per IEC 60255, plus specialized RI and RXIDG curves for complex coordination requirements.

Q: How fast can this relay respond to a high-set overcurrent fault?

A: In a high-set fault scenario (I>>), the SPAJ140C can initiate a trip signal in approximately 40 ms, ensuring rapid isolation to protect upstream equipment from thermal stress.

Q: Does the unit provide a history of fault events?

A: Yes, the SPAJ140C includes integrated fault recording capabilities, allowing technicians to analyze the magnitude and duration of recent disturbances for better maintenance planning.

Q: Can I change the relay settings remotely?

A: While physical settings are secure, the unit features binary inputs that allow for remote switching between pre-configured setting groups or for manual resetting of latched output relays.

Q: What is the benefit of the combined Earth-Fault and Overcurrent architecture?

A: Consolidating these functions reduces the physical footprint in the control cabinet and simplifies the diagnostic interface, providing a single point of truth for feeder health.