Single Phase Solid State Relay SSR 10A–120A | DD DA AA 24V 220V

Single Phase Solid State Relay — 10A to 120A | DD, DA & AA Configurations

Upgrade your electrical control systems with this high-performance Single Phase Solid State Relay (SSR). Available in current ratings from 10A to 120A and three control configurations — AA (AC controlled AC), DA (DC controlled AC), and DD (DC controlled DC) — this relay is engineered for reliable, silent switching in industrial, commercial, and DIY applications. With no moving parts, it offers faster switching speeds, longer service life, and reduced electromagnetic interference compared to traditional electromechanical relays.

Made in Mainland China.

Available Control Configurations

• AA – AC Controlled AC: 10A, 20A, 25A, 40A, 60A, 80A, 100A, 120A
• DA – DC Controlled AC: 10A, 20A, 25A, 40A, 60A, 80A, 100A, 120A
• DD – DC Controlled DC: 10A, 25A, 40A, 60A, 80A

How to Select the Right Current Rating

Choosing the correct SSR current rating is simple — just follow these two steps:

1. Calculate your load current: Equipment Power (W) ÷ Voltage (V) = Current (A)
2. Apply the load coefficient:
   • Resistive loads (e.g. heaters): multiply by 60% (use 60% of rated SSR current)
   • Inductive loads (e.g. motors): multiply by 30% (use 30% of rated SSR current)

Example: For a 1,500W motor (inductive load) running on 220V: 1,500W ÷ 220V ≈ 6.8A. Then 6.8A ÷ 0.30 ≈ 22.7A — select the 25A SSR.

Key Features

• Wide current range: 10A, 20A, 25A, 40A, 60A, 80A, 100A, 120A
• Control voltages: 24V DC / 220V AC input options
• Three configurations: DD, DA, AA for maximum flexibility
• No moving parts — silent, spark-free switching operation
• Fast switching response & long operational lifespan
• Compact, panel-mount-ready design with easy wiring terminals
• Compatible with PLCs, microcontrollers, temperature controllers, and automation systems
• Condition: Brand New

Typical Applications

• Industrial heating and temperature control systems
• Motor control and variable-speed drives
• Lighting control panels
• HVAC and ventilation automation
• PLC and microcontroller output switching
• DIY electronics and home automation projects

Safety & Standards

For guidance on electrical safety practices and proper installation of switching devices, refer to the OSHA Electrical Safety Standards. Always ensure installations are performed by a qualified electrician and comply with local electrical codes.

Frequently Asked Questions

Q: What is the difference between DD, DA, and AA solid state relay types?

A: These designations refer to the control and load signal types. DD (DC controlled DC) uses a DC signal to control a DC load. DA (DC controlled AC) uses a DC input signal to switch an AC load — ideal for use with PLCs and microcontrollers. AA (AC controlled AC) uses an AC control signal to switch an AC load. Choose based on your control source and the type of power your load requires.

Q: What current rating solid state relay do I need for my application?

A: Calculate your load current (Watts ÷ Volts = Amps), then divide by the load coefficient: 0.60 for resistive loads (e.g. heaters, lamps) or 0.30 for inductive loads (e.g. motors, solenoids). Select the next available SSR rating above your result. For example, a 1,500W inductive motor on 220V requires a 25A SSR.

Q: Does this solid state relay require a heatsink?

A: For higher current ratings (typically 40A and above), a heatsink is strongly recommended to dissipate heat generated during operation and ensure long-term reliability. Lower current models (10A–25A) in well-ventilated environments may operate without one, but adding a heatsink always extends component lifespan.

Q: Is this SSR compatible with PLC and Arduino/microcontroller systems?

A: Yes — the DA (DC controlled AC) and DD (DC controlled DC) variants are fully compatible with 3–32V DC control signals, making them ideal for use with Arduino, Raspberry Pi, PLCs, and other low-voltage control systems. Always verify the control voltage range of the specific variant you select.