How to connect wall power to PCB?

Hi - a board I'm making is switching a 120VAC line. I'm trying to figure out how to connect the 120VAC input and output lines to the PCB. Normal house wire (solid, 14 awg I think, but I could be remembering wrong) will be connected to the board. I was thinking some sort of screw mounting system (like that which you see in most home wiring (ie switches, power sockets, etc.). Any suggestions as to a manufacturer or a board mount device along those lines? Or is there a better way to do this? Thanks!

-Michael Noone

Hello Michael,

Almost any connector manufacturer offer lots of different solutions here. Take your pick:

Regards, Joerg

Oh good grief. The moment I read the OP's post I figured someone would have said something like this.

Stop being so eliteist. If everyone followed your advice then noone on earth would know how to work with mains voltage since noone is born with innate knowledge of mains wiring practice. At some point in the learning process everyone has to ask questions (either to other humans or to reference materials) and find the answers.

The mains aren't all that dangerous and besides, everyone dies someday. It is only a matter of when and how. I say it is better to live a little and take *necessary* risks than to live a life cowering in mortal fear of everything and ultimately end up doing nothing in life.

Pull apart an old toaster and have a look. They have power direct to PCB.

Cheers.

You are very judgmental of the OP. Considering the brevity of his post I don't see how an accurate or fair assessment of his capabilities can be made.

That said I don't see anything inherently wrong or otherwise dangerous about what the OP was suggesting. Granted it is far more common to find products that use a captive cable (or a detachable cable with properly molded connections) using stranded wire and are plugging into standard outlets, than to find a wiring scheme like the op suggested. On the other hand given the right circumstances it is conceivable such a wiring scheme would be justifiable. Higher power products that will always remain stationary are possible examples (ex: house air conditioner). The OP didn't specify what his product was or why direct wiring made sense in his application.

If you can point to a relevant code or safety standard the OP is clearly intending to violate, I would be more swayed by your position.

Well, I do, primarily wanting to connect 14 AWG solid wire to a PCB. If OP is switching so many amps that he needs #14, then the current shouldn't go through a PCB, unless it's specially designed for that kind of current.

One of the others mentioned a proper relay or contactor, and just do the control circuitry on the PCB. That's probably what I'd suggest. And stranded wire.

Thanks, Rich

Rich Grise wrote in news: snipped-for-privacy@example.net:

Current should be 2-5 amps. I was planning on just using as wide of traces as possible - probabaly about half an inch. I was also probabaly going to put these traces on both sides of the PCB. (directly above and below each other). The reason I'm using solid wire is because that is what is used in house wiring - and thus what will be connecting to the device. Regards,

-Michael

Hi. I'd seriously consider mounting your switching device off the board so that you move any mechanical (and electrical isolation) problems off-board also. Solid core cable of that gauge is going to cause you grief at some stage. Depending on what your switch actually is, I'd then go for screw terminals or lugs (depending obviously on the terminals on the device) for the 120VAC and the mechanics of the control signal(s) becomes 'trivial'.

Cheers.

Ken

"Fritz Schlunder" wrote in news:d2gpfp$v9k$ snipped-for-privacy@domitilla.aioe.org:

I expected it as well, so I didn't take offense :)

-Michael

"Fritz Schlunder" wrote in news:d2h040$5ru$ snipped-for-privacy@domitilla.aioe.org:

I'm not quite sure why a cable as you describe would be necessary - this device will be mounted within a wall, and will never be moved, thus strain on the PCB should be non existent. By the way - I should mention that probabaly a total of 5 or so of these will be made...

-Michael

I really think if you have to ask this sort of question your experience and training level is TOO low to be dabbling in mains powered devices. I hope this is for your own use and not for production. You have a lot to learn before you should attempt this sort of thing.

Nobody would connect solid wire from outside a device to a pcb.

Yeh but most people learn to crawl before they try to walk and the OP does not know enough to be playing with mains voltages without a LOT more training. Anything less is suicide or murder.

Hello Michael,

There is another, simpler method used in some X10 wall switches: Wires come out of them. These are then connected to the house wiring with wire nuts. Not that I particularly like wire nuts or the fact that they instruct you to mix stranded wire with the non-stranded house wire under these wire nuts...

I have also seen that method on regular dimmer modules.

Regards, Joerg

Yeah, Well: My money is on some electrical contractor yanking the cable hard at some point to see what it connects to (i.e. when it pops out through the plaster).

Be careful of the Insurance; Any mishap may be blamed on you.

Hello Frithiof Andreas,

No plaster in America. It's all run through holes in the wooden studs, occasionally tacked in place.

Regards, Joerg

Sheetrock internal wall board is often called plaster, plasterboard, or gyprock in other parts of the world.

The material will not matter. The only listing the OP will get is at the Undertakers not Underwriters .

Undertakers??

Would that be due to electrocution? In the country I live the main group of people killed by electrocution are electricians. This is due to the introduction of RCD (Residual Current Devices) or otherwise called earth/ground leakage devices. The general population is now by and large protected.

Cheers.