Double pole switching is perfectly reasonable, and mandatory in many situations, but your schematic is NOT doing that!
End of story.
I’m perfectly able to accept this. That is exactly the reason I came here with the question - to ask if it would work.
If you don’t understand, there’s no point asking the forum, as physics and electrical theory won’t change because it doesn’t suit your preferences.
I thought that was the point of the forum, specifically this subforum “Project Guidance
Advice on general approaches or feasibility”.
It is not my preference to use triacs. I have a problem and thought I had a solution, but figured to check with people who I consider more knowledgeable about the subject, which is, again, the whole purpose of this forum, or at least that’s the impression I got.
It just puzzles me why are you acting like a child that tells they have a secret but won’t tell what it is. For the amount of effort you put into your “It won’t work” posts, you could have easily written three sentences describing why. I appreciate and thank you for your enthusiasm to help me stay off the dead end path, but I would appreciate even more if you told me why.
There may be another issue worth exploring.
TRIACs won’t provide the electrical isolation to make the circuit ‘safe’ that you’re hoping for.
In this case relays - or contactors - (wired as you have already shown) will be fine once you address the contact welding issue.
That is another part of the answer to the question I asked in the OP. Thanks.
What relays are you using?
What voltage are you switching? 110Vac or 240Vac?
Thanks for stopping by.
They are of the ebay “Arduino Relay Module” type things, with written rating of 10 A at 240 Vac.
I’m switching 240 Vac
I figured if the SMPS used 1 to 2 A, I’d be safe with them.
What advantage will switching both active and neutral have.
If you are going to work on the installation you will have , I hope, opened a master circuit breaker and checked for live devices.
Purely as an additional safety layer.
Sure, when there is work to be done on the device the entire thing gets unplugged from the wall, but on occasion there is unrelated work needed to be done on nearby devices.
Also check the power factor of your SMPS’s as they may not be acting as a resistive load and your triacs may not switch OFF.
Also SMPS have surge currents at turn ON, they have surge limiting built in but there is still a high ON current.
Yes, I believe that is the source of the contact welding.
If you do want to play with triacs, try SSR, Solid State Relays, they are ready made assemblies that can take 5V logic level input to control AC mains.
The wiring is a lot cleaner and safer.
SSRs are definitely an option.