What am I getting into?
I want to build a commercial product that will have (2) AC plugs going into it, and these same (2) AC circuits exiting the enclosure.
Basically, I just want to sample whether or not the AC line is energized, w ithout resorting to external sensors and wiring. Each input will utilize a power entry connector, and the corresponding outlet will use a snap-in NEM A 5-15 receptable. There are other low-voltage things going on in the box, but I will physically separate them from the high-voltage components. The only connection between the above arrangement and the rest of the design w ill be the output of an optocoupler, which samples the 120 VAC line using a 22k resistor (which I assume has to go on the 120 VAC side of things. (?)
IN:
OUT:
I plan to sample each 120 VAC line using a MID400 optoisolator designed spe cifically for this task.
OPTO:
My questions are: Is there anything special that I will need to do, beyond the obvious to....
1) Pass a HiPot test 2) Pass an appropriate product safety evaluation on this 120 VAC / MID400 s etup 3) Do I need to cut slots in the circuit board to further separate the 120 from everything else under the unitized chassis cover? 4) I intend to use a fiberboard (or whatever you call it) physical barrier to completely enclose the 120 VAC power entry / outlet, connecting wires an d terminals, etc.. so that they are separate from everything else. 5) My guess is we will eventually go for UL approval on this, but we're not quite to that decision-point just yet. (And for budget reasons, I will ha ve to have the answers before going that route anyway..)Note that there will be two power switches on the same chassis. Even though this chassis is not powered by these 120 VAC circuits*, it will be required that both be de-energized prior to servicing, etc... It is po ssible that one of these 120 VAC outputs will go on to supply power to a lo w voltage DC power supply, which will in-turn power the rest of the design.
So to recap: I'm just routing these (2) 120 VAC circuits per the above des cription so I can sample them while simultaneously eliminating field wiring . If you were to open the lid on our proposed design, you would see this setu p as completely separate from the rest of the design, having only the optoc oupler output in common. Lastly, the whole contraption fits inside another NEMA-4 box, which is already meeting all the safety stuff we want it to.
I'm a bit nervous because I just don't know the "rules" for how to handle a commercial product that is "powered" by two separate AC circuits -- even t hough in this proposed arrangement, we're not powering anything -- just sam pling the presence of AC (or not) in a "goes-into"/"goes-out-of" arrangemen t.
I hope that made sense? Thanks for the assist!!