Schneider Electric S48890 Circuit Breaker Restraint Interface Module

The Schneider Electric S48890 Restraint Interface Module is a 120 V AC / 24 V DC powered protection accessory that enables zone-selective interlocking (ZSI) between Schneider Electric circuit breakers. It mounts on a DIN rail and draws about 10 W from the supply. The module coordinates signals between upstream and downstream breakers with compatible trip units (notably Micrologic series) to improve selective protection on shared feeders; up to 15 input signals can be handled by upstream breakers without needing an additional restraint interface, while more signals require a restraint interface. For 120 V / 24 V systems, S48890 is the designated version (the 240 V / 24 V version is S48895). This accessory is used in Schneider Electric protection configurations to enable zone-selective interlocking and to integrate with related GC ground-fault relays, supporting safer operation and more precise fault isolation in complex motor and distribution applications. Field installations typically place the S48890 on standard DIN rails inside control panels to provide reliable restraint signaling at industrial voltages.