The SSR-25DA Solid State Relay is a single-phase electronic switching device designed to control AC electrical loads using a low-voltage DC control signal.
Featuring a 25A rated output, 3–32V DC control input, and 24–380V AC load voltage range, this relay provides silent and reliable switching without mechanical contacts.
The SSR-25DA is suitable for industrial automation, temperature control, heating systems, and microcontroller-based switching applications.
Key Features
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25A Rated Load Current: Designed for switching compatible AC loads.
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DC-to-AC Operation: Controls AC loads using a low-voltage DC signal.
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3–32V DC Control Input: Suitable for various electronic control circuits.
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Zero-Cross Switching: Helps reduce electrical interference during switching.
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Silent Operation: No mechanical clicking or moving contacts.
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Fast Electronic Switching: Suitable for automated ON/OFF control.
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Long Service Life: No mechanical contact wear.
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Compact Design: Suitable for industrial control panels.
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Screw Terminals: Convenient electrical connections.
Technical Specifications
| Parameter |
Specification |
| Model |
SSR-25DA |
| Product Type |
Single-Phase Solid State Relay |
| Relay Configuration |
DC-to-AC |
| Rated Load Current |
25A |
| Control Input Voltage |
3–32V DC |
| Load Voltage Range |
24–380V AC |
| Switching Method |
Zero-Cross Switching |
| Output Type |
AC Semiconductor Switching |
| Switching Function |
Normally Open |
| Mounting Type |
Panel Mount |
| Connection Type |
Screw Terminals |
| Housing |
Insulated Plastic Case |
| Cooling |
External Heatsink Recommended |
Terminal Configuration
| Terminal |
Function |
| 1 |
AC Load Terminal |
| 2 |
AC Load Terminal |
| 3 (+) |
DC Control Positive |
| 4 (−) |
DC Control Negative |
Always follow the terminal markings printed on the relay.
Microcontroller Compatibility
The SSR-25DA can be controlled using suitable DC control circuits, including:
- Arduino UNO and Mega
- ESP32 Development Boards
- ESP8266 Modules
- Raspberry Pi GPIO Systems
- PLC Controllers with DC Outputs
Important: Direct GPIO control is not guaranteed. Verify the relay's required input current and the controller's output capability. A transistor driver may be necessary, particularly with 3.3V GPIO systems.
Applications
- Industrial Automation
- Temperature Control Systems
- Electric Heating Equipment
- AC Lighting Control
- Industrial Control Panels
- Arduino and ESP32 Projects
- Raspberry Pi Automation
- Automated AC Load Switching
- Compatible AC Motor and Fan Switching
Important Notes
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High Voltage Warning: AC wiring must be performed by qualified personnel.
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This is a DC-to-AC relay, designed for DC control signals and AC loads.
- Not suitable for switching DC loads.
- A suitable heatsink is required for higher-current applications.
- The 25A rating depends on proper cooling and operating conditions.
- Use appropriate circuit protection and account for load inrush current.
- A small leakage current may be present when the relay is OFF.
- Zero-cross switching is intended for compatible AC ON/OFF loads, not phase-angle dimming or motor speed control.
- For inductive loads, verify compatibility and provide appropriate protection.
Package Includes
