HYUNDAI AOJ-1SF-B

Overview

HYUNDAI AOJ-1SF-B is an auxiliary relay from Hyundai Electric, widely used inside MV switchgear, protection panels and MCC cabinets together with Hyundai protection relays such as REF and HIMP series for trip circuit supervision, interlock and signal transfer. HYUNDAI AOJ-1SF-B is a plug-in type control auxiliary relay with multiple changeover contacts, designed for reliable switching of DC and AC control circuits. HYUNDAI AOJ-1SF-B is stocked as exchange spare for substation and marine control panel maintenance.

Features

HYUNDAI AOJ-1SF-B adopts sealed relay construction with stable contact performance for frequent control signal switching. It provides multiple potential-free changeover contacts to transmit trip status, breaker position, protection alarm and interlock signals between protection relays, breaker control circuits and SCADA/PLC systems. HYUNDAI AOJ-1SF-B supports coil voltage variants defined by suffix code, and the SF specification indicates supervision-friendly contact arrangement for trip circuit monitoring schemes. It has low coil power consumption and high contact stability, suitable for long-term continuous energized operation in cabinet environments. HYUNDAI AOJ-1SF-B supports visual coil and contact inspection after removing the plug-in unit, and it meets industrial EMC standards for substation control room installation.

Specs

HYUNDAI AOJ-1SF-B plug-in socket mounting design, contact configuration and coil voltage are determined by the full part suffix. Contact rating is for low-power control circuits, not for direct heavy load switching. It is commonly matched with 24VDC, 48VDC, 110VDC or 220VAC coil options for protection and breaker control circuits. DIN rail socket mounting, compact size for panel layout. HYUNDAI AOJ-1SF-B is widely supplied as spare for relay replacement during switchgear overhaul.

Principle

HYUNDAI AOJ-1SF-B operates when the control coil receives energizing signal from protection relay or breaker auxiliary circuit. The internal armature pulls in and changes the state of all changeover contacts to pass control or status signals. When the coil is de-energized, spring force resets all contacts back to default state. The contacts of HYUNDAI AOJ-1SF-B are wired into trip interlock, proof trip and alarm signal loops. The control system can judge relay health and circuit continuity by monitoring contact status. If coil burnout or contact sticking occurs, the control logic can capture abnormal status and raise alarm.

Applications

HYUNDAI AOJ-1SF-B is used in medium voltage feeder protection panels, breaker control cubicles, generator protection cabinets and marine switchboards. Typical duties: protection trip amplification, interlock logic transfer, breaker position signal duplication and alarm routing for SCADA SOE logging. HYUNDAI AOJ-1SF-B is selected for spare inventory, panel retrofit and replacement when auxiliary relays fail in Hyundai Electric protection and control schemes. It is a common auxiliary signal relay for power system secondary control circuits.