Triac Power load regulator project

[strawberry]

Vin : 240VAC 50Hz (can work on 110V with simple mod)
Iout : 20A rms
Regulation : 15...95%
Board dimensions 45x45mm
Simple heatsink mounting using 4x M3 standoffs
PCB fabricator will be PCBway

[dmills]

You have nowhere near sufficient clearance between that pour connected to Neutral and the mounting holes (2 - 3mm is usually about right depending on the degree of atmospheric contamination and the tracking index of the PCB material in use (Tracking index is somewhat variable depending on the quality of the PCB, ask board house for this information)).

Also the pot mounting bracket is connected to a live conductor (Phase and Neutral are both 'Live' conductors for the purposes of safety, and should be treated as such), you might want to earth this instead or use an all plastic pot.

Please tell me the Triac is an isolated tab model and that the heatsink is grounded.

There is, I take it a honking great inductor for RFI suppression somewhere in the system, or that thing will radiate from DC to daylight.

Regards, Dan.

[strawberry]

Warnishing will help or dialectric spray to increase reliability.

Designed with plastic knob

non, Isolated with silicon isolator . grounded heatsink

It is universal boart, all rfi/emi filters will be dependant on individual design, but TRIAC have R/C snuber to reduce rf or it only serve to reduce rise time of TRIAC current.. and how to calculate it?

[dmills]

Varnish or spray will not get you clearance that is not there, I would suggest a clearance between mounting hole copper and **Anything** else on that board of maybe 2.5mm to 3mm would be the correct fix.

Is the threaded part of the pot plastic? It is important that no part of that mounting bracket be accessible even if the knob is removed or snapped off. 

The snubber will only really work in conjunction with an external inductor to limit RFI, on its own it may help with di/dt somewhat but that will depend a lot on the load.

You generally use the biggest inductor that will fit in the case, consistent with Isat being high enough.

There is a reason designing directly mains connected electronics is a pain the the arse.

Regards, Dan.

[strawberry]

Metal part of the pot is grounded to heatsink via bras standoff.

should help pcb cutouts Not clear how it will be made and what files do they need?

[strawberry]

Altium source files. https://drive.google.com/open?id=0BwVLiaRx-ca4d2g1b3B3WHlRR3c

[Zero999]

You have nowhere near sufficient clearance between that pour connected to Neutral and the mounting holes (2 - 3mm is usually about right depending on the degree of atmospheric contamination and the tracking index of the PCB material in use (Tracking index is somewhat variable depending on the quality of the PCB, ask board house for this information)).

That depends on what will be attached to the mounting holes.

If it's on metal threads in a metallic enclosure, then yes it will present a safety issue but If it's in a plastic box or on nylon spacers, then no problem.

[strawberry]

End result without heatsink.