For one of my projects I’m planning on controlling my water heater. To do this, I needed a relay. I ended up finding a good deal on ebay for the Crydom D2450 SSR.
This relay will operate between 3-32V DC on the input. This works great with the Raspberry Pi’s 3.3V GPIO.
The following is a basic guide to wiring and testing the relay with the Raspberry Pi.
1. Connect a ground pin from the Raspberry Pi to position 4 on the relay. I chose pin 6.
2. Connect one of the GPIO pins to position 3 on the relay. I’d recommend one you already know you can control using whatever language you’re familiar with (python, java, c++). I used GPIO 4 in the picture.
3. Next comes the AC cabling. For my test I used a cheap extension cord for a household 120V AC outlet and connected the hot through the relay. The neutral stays as is. You can connect either side of the hot leg on positions 1 and 2.
4. Next you’ll need some sort of load connected to the circuit or the SSR wont work. You’ll notice that with voltage applied and not applied to the input, you’ll still have voltage on the circuit. A simple lamp will work for testing purposes.
5. With everything connected, you should now be able to control the AC load by simply turning off or on the GPIO output you selected.
This topic was modified 3 years, 8 months ago by Z.