How to Use SSR-10A: Examples, Pinouts, and Specs

The SSR-10A is a solid-state relay (SSR) designed for switching AC loads. Unlike traditional electromechanical relays, the SSR-10A uses semiconductor components to perform switching operations, ensuring high reliability, fast response times, and silent operation. This relay is particularly well-suited for applications requiring precise control of electrical devices without mechanical wear.

• Industrial automation systems
• Heating, ventilation, and air conditioning (HVAC) systems
• Motor speed control
• Lighting control systems
• Home appliances and smart home devices
• Temperature control in ovens and furnaces

1. Control Side (Input):

   • Connect the positive control signal (3–32V DC) to the Input (+) pin.
   • Connect the ground of the control signal to the Input (-) pin.
   • Ensure the control voltage is within the specified range to avoid damage.

2. Load Side (Output):

   • Connect one terminal of the AC load to the Output (L1) pin.
   • Connect the other terminal of the AC load to the Output (L2) pin.
   • Ensure the load voltage and current do not exceed the SSR-10A's ratings.

3. Power Supply:

   • Ensure the AC load voltage is within the range of 24–380V AC.
   • Verify that the load current does not exceed 10A.

4. Mounting:

   • Secure the SSR-10A to a heat sink or panel using screws to ensure proper heat dissipation.
   • Use thermal paste if necessary to improve heat transfer.

• Always use a heat sink for high-current applications to prevent overheating.
• Avoid exceeding the maximum load current (10A) to ensure long-term reliability.
• Use a snubber circuit or varistor across the load terminals to protect against voltage spikes.
• Ensure proper electrical isolation between the control and load sides.
• Double-check all connections before powering the circuit to avoid damage.

Below is an example of how to use the SSR-10A to control an AC lamp with an Arduino UNO.

• Connect the Arduino's digital pin (e.g., pin 9) to the Input (+) pin of the SSR-10A.
• Connect the Arduino's ground (GND) to the Input (-) pin of the SSR-10A.
• Connect the AC lamp to the Output (L1) and Output (L2) pins of the SSR-10A.
• Ensure the AC lamp's voltage and current are within the SSR-10A's specifications.

// Example code to control an AC lamp using SSR-10A and Arduino UNO

const int ssrPin = 9; // Define the pin connected to SSR-10A Input (+)

void setup() {
  pinMode(ssrPin, OUTPUT); // Set the SSR pin as an output
}

void loop() {
  digitalWrite(ssrPin, HIGH); // Turn on the AC lamp
  delay(5000); // Keep the lamp on for 5 seconds

  digitalWrite(ssrPin, LOW); // Turn off the AC lamp
  delay(5000); // Keep the lamp off for 5 seconds
}

• Use a proper AC-rated fuse in series with the load for safety.
• Ensure the Arduino and SSR-10A share a common ground.

1. Can the SSR-10A switch DC loads?

   • No, the SSR-10A is designed specifically for AC loads. For DC loads, use a DC-rated SSR.

2. Do I need a heat sink for low-current applications?

   • A heat sink is not mandatory for low-current applications, but it is recommended for currents above 5A.

3. What happens if I exceed the maximum load current?

   • Exceeding the maximum load current (10A) can damage the SSR and may cause it to fail permanently.

4. Can I use the SSR-10A with a PWM signal?

   • The SSR-10A is not designed for high-frequency PWM signals. Use it with steady-state or low-frequency control signals.

By following this documentation, you can effectively integrate the SSR-10A into your projects and ensure reliable operation.