External Relay Control Module for Access Control & CCTV Integration (Form-C Relay Output, 12V DC, Dry Contact Expansion)

Product Overview

The GV-502 External Relay Module is an auxiliary control interface engineered to expand the switching capacity, physical isolation, and integration reach of access control controllers, standalone biometric terminals, and video surveillance systems. Serving as an external relay extension, this module decouples high-current locking hardware—such as heavy-duty magnetic locks, electric strikes, automatic gate operators, and perimeter strobe sirens—from sensitive terminal mainboards, preventing back-EMF voltage spikes and electrical feedback from damaging primary controllers.

Constructed on a heavy-duty industrial PCB housed within an impact-resistant, compact ABS casing, the GV-502 features a high-reliability Form-C electromechanical relay offering Normally Open (N.O.), Normally Closed (N.C.), and Common (COM) dry contact outputs. It accepts low-voltage trigger inputs from open-collector / transistor outputs, push buttons, or auxiliary relay signals. Equipped with onboard flyback protection, an optical status indicator LED, and screw-clamp terminal blocks that accept up to 16 AWG field wiring, the GV-502 simplifies installation inside power supply enclosures, junction boxes, or controller backboxes.

✅ Key Features

• Electrical Isolation & Controller Protection: Protects primary access controllers, biometric readers, and alarm panels from inductive kickback and voltage spikes caused by heavy electromagnetic locks.

• Universal Form-C Relay Interface: Provides versatile Normally Open (N.O.), Normally Closed (N.C.), and Common (COM) dry contact outputs to match fail-safe and fail-secure lock configurations.

• High-Current Contact Rating: Handles switching loads up to 10A @ 125V AC / 30V DC, easily managing commercial door strikes, drop bolts, magnetic locks, and barrier gates.

• Flexible Triggering Inputs: Compatible with low-current dry contact closures, NPN open-collector signals, or active low/high DC voltage triggers.

• Built-In Surge & Flyback Diode: Suppresses inductive switching transients, eliminating the need for external clamp diodes across DC magnetic coils.

• Visual Relay Status LED: Onboard status indicator lights up when the relay coil is energized, streamlining field diagnostics and circuit testing.

• Screw Terminal Connections: Heavy-duty captive screw terminal blocks provide secure, vibration-resistant termination for 16–26 AWG field wiring.

• Compact Footprint: Easily mounts inside power supply distribution cabinets, junction boxes, or architectural hollow metal door frames.

Compatible Devices

• Multi-Door Networked Access Control Panels (such as ZKTeco C2-260, InBio series, and universal Wiegand controllers)

• Standalone Biometric & RFID Terminals (Face recognition, fingerprint, and PIN keypads)

• Heavy-Duty Magnetic Locks (600 lbs / 1200 lbs electromagnetic locks) and Shear Locks

• Electric Door Strikes (Fail-Safe and Fail-Secure models) and Motorized Drop Bolts

• Automatic Sliding / Swing Gate Operators, Barrier Arms, and Traffic Bollards

• CCTV IP Cameras & NVRs with Alarm Output Terminals (such as IPF-B14M-A-28 alarm triggers)

• Linear Power Supplies and Battery Backup Enclosures (such as 12V DC access control power supplies)

• Request-to-Exit (REX) Push Buttons, Touch Sensors, and Wave-to-Open Switches