Industrial Solid State Relay SSR-40DA — Reliable DC-to-AC Switching Power

Upgrade your industrial control systems with this SSR-40DA Solid State Relay. Designed for demanding DC-input to AC-output switching applications, this relay delivers fast, silent, and spark-free operation — making it an ideal choice for automation panels, temperature controllers, CNC machinery, heating systems, and more. Available in multiple current ratings (10DA, 25DA, 40DA, 60DA) to match your exact load requirements.

Key Specifications (SSR-40DA)

Input Voltage: 3–32V DC
Output Voltage: 24–380V AC
Output Current: 40A
On Voltage: ≤1V
Switch-On Time: ≤10ms
Off Leakage Current: ≤2mA
Package Contents: 10 × SSR-40DA Relays

Why Choose This SSR?

✅ No Moving Parts — Solid state design eliminates mechanical wear for longer service life
✅ Fast Switching — Response time ≤10ms for precise control
✅ Low EMI — Zero-crossing switching minimizes electromagnetic interference
✅ Wide Input Range — Compatible with most PLCs, microcontrollers, and DC control signals (3–32V DC)
✅ High Load Capacity — Handles up to 40A output current at up to 380V AC
✅ Plug-and-Play Ready — Screw-terminal connections for quick, secure wiring
✅ Value Pack — Comes as a 10-piece set, ideal for projects, spares, or bulk installations

Typical Applications

Industrial automation and PLC control panels
Heating element and temperature controller circuits
Motor control and power switching
3D printer heated beds and CNC systems
HVAC and pump control systems

Available Current Ratings

Choose from 10DA, 25DA, 40DA, or 60DA versions to perfectly match your load requirements. Each shares the same 3–32V DC input and 24–380V AC output specifications.

For information on electrical safety standards and best practices for industrial control equipment, visit the U.S. Occupational Safety and Health Administration (OSHA) — Electrical Safety.

Frequently Asked Questions

Q: What does SSR-40DA mean and what does this solid state relay do?

A: SSR stands for Solid State Relay, and "40DA" indicates a 40-Amp DC-to-AC model. It allows a low-voltage DC control signal (3–32V DC) to switch a high-voltage AC load (24–380V AC, up to 40A) without any mechanical contacts — providing fast, silent, and long-lasting switching for industrial and automation applications.

Q: Is this solid state relay compatible with Arduino, Raspberry Pi, or PLCs?

A: Yes. The 3–32V DC input range is directly compatible with most microcontrollers (including Arduino and Raspberry Pi GPIO pins with appropriate interfacing), PLCs, and other standard DC control sources, making integration into automation projects straightforward.

Q: Do I need a heat sink with this SSR?

A: At higher current loads (typically above 10A continuous), a heat sink is strongly recommended to dissipate heat and maintain reliable long-term performance. The relay's flat metal back is designed to mount directly onto an aluminum heat sink using thermal compound for optimal heat transfer.

Q: What is included in the package?

A: Each order includes 10 × SSR-40DA Solid State Relays (40A / 250V / 3–32V DC input). This value pack is ideal for bulk wiring projects, automation panels, or keeping spares on hand.

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