PCB, mains power

[Lee Groom]

I have a relay actuator and was thinking it tidying it up be putting on a FR4 pcb with a hilink HLK-PM01 220v to 5v.

Am I ok to put 220v on an FR4 proto board??

[sundberg84]

There is several projects on openhardware.io that does this and alot of discussions on the forum for safety regarding 220v to 5v.
No project is without disclaimer that you use it on your own risk - because thats what we do here - diy.

How I have understood it (can not garatee its right) is that FR4 is the worst material to use (offcourse since its cheapest) and therefore it requers the longest creepage and clearance. Also a good thing is to seperate high voltage (primary side) and low voltage (secondary). Use 3 mm as creepage. Also dont put it in a dirty/high humidity enviroment... this is how far i have come... but I still have alot of questions to work out...

Some links:

http://forum.mysensors.org/topic/1607/safe-in-wall-ac-to-dc-transformers
https://www.openhardware.io/view/13/In-Wall-ACDC-Pcb-for-MySensors
https://www.openhardware.io/view/77/AC-DC-double-solid-state-relay-module
https://www.openhardware.io/view/83/Smart-Light-Switch-220v