SSR-25DA 25A Solid State Relay – DC to AC, 3-32V Input, 24-380V Output

The SSR-25DA is a 25A solid state relay designed for DC to AC switching, allowing low-voltage DC control signals to manage higher-voltage AC loads. It accepts an input voltage of 3-32V DC and can switch loads up to 25A at 24-380V AC. The relay uses zero cross switching, which reduces electrical noise and inrush current, making it suitable for resistive and inductive loads. Because it has no moving contacts, it provides silent operation, fast switching, and a long service life compared to mechanical relays. This 25A SSR module is commonly used in industrial automation, temperature control systems, lighting control, and DIY projects with Arduino or PLC controllers. The SSR-25DA is compatible with Fotek-style mounting and wiring, featuring screw terminals for easy installation. Proper heatsinking is recommended when operating near the rated current to ensure reliable performance.

1. Industrial heating control (heaters, heating elements).
2. Light motor control and small inductive loads.
3. Home automation and smart thermostats.
4. PLC, Arduino, and microcontroller-based automation projects.
5. Laboratory equipment and temperature control systems.
6. Silent switching for LED or halogen lighting.

1. Model: SSR-25DA.
2. Rated load current: 25A (resistive load).
3. Input voltage: 3-32V DC (official Fotek datasheet: 4-32V DC).
4. Output voltage: 24-380V AC.
5. Switching method: zero cross trigger.
6. Trigger current: 12mA max.
7. Isolation strength: 4kV RMS.
8. Dimensions (L × W × H): 60 × 45 × 24 mm (distributor data).
9. Weight: 92 g (distributor data).
10. Terminals: screw terminals for input and output.

1. Solid-state design with no moving contacts for silent and wear-free operation.
2. Zero cross switching reduces electrical noise and inrush current.
3. Wide input voltage range (3-32V DC) compatible with logic-level controllers.
4. High current capacity (25A) for demanding AC loads.
5. Screw terminals for secure and easy wiring.
6. Long service life and high reliability compared to mechanical relays.