When SSD relay triggered from Arduino Microcontroller board the relay LED illuminates but FANs are not ON, they sounds and the fan blades rotates vary slow (approximate one rotation in 20-30 Seconds).
I don’t know why this is not switching correctly, while connecting without SSD directly all FAN working ok.
The current rating of relay is 40 A and all 4 FAN current rating is not more than 12 A.
Can anyone help me in diagnosing and identifying the problem here.
If that SSD is Chinese don't be surprised if the main triac inside is rated for a lot less then 40 amps.
Also check the temperature of the SSD. It might need a heat sink.
The SSD relay is working when I used transistor with Arduino at 12V. I left the all 4 exhaust fans for 2 hours and then checked SSD relay temperature, it was not heating. But yes if I will increase load then will definitely use heatsink. Thanks for the suggestion.