I am trying to control my 2 hp 240AC single phase motor with help of an arduino. Right now it is controlled via a contactor with 220-240 AC coil input voltage with help of NO and NC switches.
Following is what i am trying to achieve: Pardon my poor skills
Following is the 10A relay i am planning to use to control the contractor:
Following is the snubber circuit I have come to accept to the best of my abilities.
In the snubber circuit I am using 2000V 104J capacitor: Following is the image:
From what i could gather I am planning to use 20D271K as the varistor. Following one
Varistor
My question is will this work? I apologise for poor circuit diagrams. I will get an electrician to install these. The motor will be switched on 2 times a day for roughly 30 mins.
Help is highly appreciated.
Best Answer
Don't switch the load directly! There is already a contactor in the circuit whose One Job is to switch the load. Have your relay switch the contactor coil.
Now you need a much smaller relay, and your snubbing problem is much smaller.
The contactor coil will also be an inductive load and may need snubbing, but nothing like the motor!