What have i done wrong

[RGbee]

This has been posted elsewhere on the forum, but i have a question for all you electrical gurus out there,
Don't quite know how, but i fried both the 5v Meanwell PSU and the green on Satuday
As you can see below, for the quick and dirty test, i wired in 2 separate 3 pin plugs and connected each one to a psu (one for the scanners and the meanwell for the lasers) just to get the thing going




With the optics deck separated from the plate with the power supplies, everything worked ok.
However, the second the plates were placed together the supply and green failed.

What have i done wrong.

ps.
Once the IEC connector is mounted, i'll have an earth bolt on the bottom plate and both psu's earths will be attached to it

[dsli_jon]

Hey RG -

..don't have a lot of time, atm, but..

What have i done wrong.

...need a bit more info, por favor..

...but i fried both the 5v Meanwell PSU and the green on Satuday

a) how do you know the Green is *fried*? Does your comment imply that you've already tested it on another supply / driver? Perhaps it's just an issue w/ the Meanwell.. I know that would likely be the first thing you checked, but.. gotta start somewhere..

..However, the second the plates were placed together the supply and green failed.

Question: Any-chance your Line (hot) and Neutral (N, not Gnd..) might be 'swapped'? In other words, if you don't yet have the baseplate connected to AC earth-ground, and the L / N were somehow swapped, that could run AC thru the baseplate, and, once the (likely) case-grounded Green touched the baseplate thru the top, that could've send AC-back thru the DC-ground, and sure, that could 'fry' a supply / driver..

..in cany-case, obviously you had something running thru the plate, that should not have-been.. I'd Ohm-out a) the baseplate to AC earth ground (measuring for any AC being passed thru the plate - that could indicate a 'swapped' L and N, since in some supplies, if the Neutral can be connected to the PS-case, and so can the 'DC-common', so since you didn't have earth-ground, any AC-running thru the baseplate, could get back to DC - thru the laser-case = not-good ...)

Not-familiar with that model of PS, so, don't know how that case is or is-not isolated.. Also, the Green.. I'd also (with power-disconnected..) b) Ohm-out different points in the PJ / PSUs, and find out / post-up your 'commonalities' - in other words, what ohms-out to what.. that could help us remotely figure out 'what you did wrong'.. ..(if-anything..

i'll have an earth bolt on the bottom plate and both psu's earths will be attached to it

Always good to have, in-place, even for testing.. Also, did this up for a Client, recently, and been-meaning to post... Gotta put it in the 'Wiki', also, but haven't had the time..



..Study, and post up questions.. I'll do my best to answer yer-questions (or others can..) when I grab a few min's here / there... Does-not specifically-address your-config, etc (does not have diode / driver-psu's in-play, etc..) but the 'principles', therein, can help you 'think thru it'.. fwiw..

Hope this might help..
cheers..
j

PS - cute-little pj, btw.... Nice werk..

[swamidog]

you misspelled "diagram".

(ducking)

Hey RG -

..don't have a lot of time, atm, but..



...need a bit more info, por favor..



a) how do you know the Green is *fried*? Does your comment imply that you've already tested it on another supply / driver? Perhaps it's just an issue w/ the Meanwell.. I know that would likely be the first thing you checked, but.. gotta start somewhere..



Question: Any-chance your Line (hot) and Neutral (N, not Gnd..) might be 'swapped'? In other words, if you don't yet have the baseplate connected to AC earth-ground, and the L / N were somehow swapped, that could run AC thru the baseplate, and, once the (likely) case-grounded Green touched the baseplate thru the top, that could've send AC-back thru the DC-ground, and sure, that could 'fry' a supply / driver..

..in cany-case, obviously you had something running thru the plate, that should not have-been.. I'd Ohm-out a) the baseplate to AC earth ground (measuring for any AC being passed thru the plate - that could indicate a 'swapped' L and N, since in some supplies, if the Neutral can be connected to the PS-case, and so can the 'DC-common', so since you didn't have earth-ground, any AC-running thru the baseplate, could get back to DC - thru the laser-case = not-good ...)

Not-familiar with that model of PS, so, don't know how that case is or is-not isolated.. Also, the Green.. I'd also (with power-disconnected..) b) Ohm-out different points in the PJ / PSUs, and find out / post-up your 'commonalities' - in other words, what ohms-out to what.. that could help us remotely figure out 'what you did wrong'.. ..(if-anything..



Always good to have, in-place, even for testing.. Also, did this up for a Client, recently, and been-meaning to post... Gotta put it in the 'Wiki', also, but haven't had the time..



..Study, and post up questions.. I'll do my best to answer yer-questions (or others can..) when I grab a few min's here / there... Does-not specifically-address your-config, etc (does not have diode / driver-psu's in-play, etc..) but the 'principles', therein, can help you 'think thru it'.. fwiw..

Hope this might help..
cheers..
j

PS - cute-little pj, btw.... Nice werk..

[dsli_jon]

you misspelled "diagram". (ducking)

..Al contrario, amigo! YOU WIN THE $64 MILLION DOLLHAIR "SPEHL-CHEKURR CHAMPEEN PRYZE!!!

thx for the spot.. told ya I've been overwerked...
ciao
j

[RGbee]

Hi Jon, I posted the same question in the 'New mini RGB thread:
http://www.photonlexicon.com/forums/...GB-build/page4
Post number #83
I've separately tested the green on a bench PSU and it's definately packed up

In order to do a quick alignment test i rigged up both the scanner PSU and the Meanwell driving all the lasers to separate 3 pin plugs (so not earthed directly to the chassis)
With the base plate and optics deck separated, everything ran well, but the second i placed the optics deck on top of the base plate the green packed up together with the Meanwell.
I now understand why the green popped though. It was not isolated in any way from the plate and i was replying on the highside driver to give some form of protection.
I have an identical replacement PSU arriving today. This time though, i will wire in both supplies to the same 240vac input and ensure they are earthed to a common ground pin on the chassis (i'm hoping that was in some way the cause of the PSU failure). When the replacement green arrives next week, and as per the helpful suggestions in the thread above, i will also completely isolate it from the plate on which it's mounted.
Thanks for the schematic!. I'm using a spare DZ breakout board. I have the X/Y wired in, but is it advisable to wire the (white) ground wires?

[ATTACH=CONFIG]37393[/ATTACH
Many thanks
Adrian