ABB SPAJ140C Over-Current and Earth-Fault Relay

Overview

The ABB SPAJ140C is a digital overcurrent and earth-fault relay designed for medium-voltage feeder protection. Engineers use it in directly earthed, resistance-earthed, or impedance-earthed systems. This compact unit combines multiple protection, monitoring, and control functions into one reliable device. Its robust design ensures dependable operation across harsh environments. Moreover, it supports easy integration with modern SCADA systems via Modbus RTU, SPABUS, or optional fiber optics. The intuitive LCD interface simplifies configuration, diagnostics, and status viewing on-site.

Technical Specifications

Model: SPAJ140C
Protection Functions:

• Phase Overcurrent (Low-set / High-set)

• Earth-fault Protection (Low-set / High-set)

• Breaker Failure

Rated Input Current:

• Selectable 1 A or 5 A via terminals

Rated Frequency:

• 50 Hz or 60 Hz

Auxiliary Voltage Supply:

• 80–265 V AC

• 18–80 V DC

Time Characteristics:

• Definite Time (DT)

• Inverse Definite Minimum Time (IDMT)

Supported IDMT Curves:

• Normal Inverse

• Very Inverse

• Extremely Inverse

• Long-time Inverse

• RI

• RXIDG

Output Relays:

• 2 heavy-duty (trip capable)

• 4 light-duty (signaling or logic)

• All relays are field-configurable

Communication Interfaces:

• RS-485 (Modbus RTU)

• SPABUS

• Optional fiber optic module

Self-Supervision:

• Continuous hardware and software monitoring

• Auto-diagnosis with alarm signaling

Display:

• LCD for configuration, measurements, and fault records

Operating Temperature:

• –25°C to +70°C

Physical Dimensions:

• 150 × 240 × 350 mm

Weight:

• 1.9 kg