Isolated relay module to control heavy appliances upto 30A

30A Isolated Relay Module for MCU and Microcontroller Projects

The RELAY30A is a DIN rail-mounted 30A relay module designed for safe control of high-current AC and DC loads from a microcontroller. A built-in transistor driver and an independent 5V relay power supply mean your MCU GPIO never directly drives the relay coil — protecting your controller from inductive spikes and current overload.

The Problem It Solves

Relay coils draw 60–100 mA. Most MCU GPIO pins are rated for 8–20 mA. Connecting a relay directly to a GPIO pin risks damaging the MCU or causing erratic behaviour. The RELAY30A solves this with a transistor stage: the MCU sends a low-current logic signal, the transistor drives the relay coil from the independent 5V supply. The MCU sees zero inductive kickback.

How It Connects

• Control input: NO/NC logic input — connect directly to any MCU GPIO (Arduino, ESP32, Raspberry Pi, STM32, or any 3.3V/5V logic)
• Relay power: Independent 5V supply powers the relay coil — completely separate from the MCU supply
• Load side: Up to 30A, AC or DC — connect your pump, motor, solenoid valve, heater, fan, or any heavy appliance

Use Cases

• Industrial automation — MCU-controlled switching of pumps, motors, compressors, solenoid valves
• Building automation — control HVAC contactors, lighting circuits, heating elements from a controller
• IoT edge devices — add high-current relay output to any WiFi, LoRa, or 4G IoT controller
• Panel builders — clean DIN rail integration into control panels and distribution boards
• Prototyping and field devices — safe relay output for custom embedded designs without additional driver circuits

Key Specifications

• Relay rating: 30A
• Load voltage: AC and DC
• Control input: NO/NC — compatible with 3.3V and 5V MCU GPIO
• Isolation: Transistor driver isolates MCU from relay coil current
• Relay power supply: Independent 5V input (does not draw from MCU supply)
• Mounting: DIN rail
• Design: Manufactured in-house