Power supply w/o ground

I assume you are asking about Earth Grounds. Some devices operate safely with them. You should be go to go ... but it depends on worst cases and possible litigation.

WTH is 'go to go'? It's time to up your meds, again. ;(

Where did you expect to see a GROUND and why ?

Plenty of power supplies don't have them and don't need them. See Class II insulation.

Graham

The AC-to-DC switching regulator power supply you're using has an isolated output, meaning it's constructed so there's no inherent connection between either the positive or negative end of the 3.3VDC supply and anything else.

Actually, the data sheet suggests there's more than 4KV isolation between the line voltage input side and the output. I'd take that with a grain of salt, but it does tell you there's no inherent danger involved in either leaving the supply output floating, or grounding it.

If you need a grounded supply (think twice before doing this unless you have to -- most times, in industrial applications grounding the supply causes more difficulty than it solves), you can just connect the earth ground wire to the negative terminal of the supply (or the positive terminal, for that matter).

Surely the Great Terrell can figure that out?

"JT"

....... Phil

"Chris"

NO SUCH DAMN THING !!

A given product is either made to meet "Class 2 " ( ie double insulation) safety requirements or it is NOT !!

If it is NOT - then all user accessible wiring & exposed metal MUST be connected to safety ground via a solid wire link.

If a product does not specifically state that it meets all Class 2 ules - NEVER assume.

Someone's life may be on the line.

....... Phil

I am not building a double-insulated Class II device. It is a power supply in a IP65 plastic enclosure, it can potentially be LOCATED OUTSIDE.

This "Cincon" (sorry Phil if I offended you.???) supply only has 2 tiny pads exposing the 120VAC to the user, I will cover these with epoxy potting compound.

Class I says the chassis should be grounded but the chassis is plastic. There will be an Earth Ground line coming in, should I just connect it to the AC Neutral terminal?

Or, is this supply specifically design for Class II and I need to find another?

"JT"

Got a clue what one is ??

External PSU are nearly all required to be Class 2 devices

- by LAW !!!

Take a look at any wall wart or phone charger.

If there are no marking re Class 2 compliance

- it damn well AIN'T !!!!!!!!

....... Phil

Please clarify "external PSU". You imply...external to the product, like a wall wart. My design will have the PSU internal to the product. The entire product and PSU is in the IP65 housing, there are no other connections or outputs. So I think I am still looking at a Class I device, correct?

There are no "outputs". There will be an Earth Ground conductor coming in, should I just connect it to the AC Neutral terminal?

Perhaps someone can suggest how to safely wire and enclose a small 3.3V device with 120VAC power supply for use outdoors. TIA

"JT"

Polyester resin is top stuff.

..... Phil

If it's not Class II then it's presumably Class I which requires an earth.

If you need to ask, quite frankly you shouldn't be building anything like this.

I suggest you read up on safety standards.

Graham

Frankly, if you think such an idea is even remotely acceptable you deserve to be shot.

Graham

DO NOT connect the earth ground (safety ground, green or green/yellow wire) to the neutral in your equipment. The safety ground should be connected to any exposed metal (or otherwise conductive) parts of your equipment.

If your device has no exposed metal parts, do not connect the green (or green/yellow) safety ground to anything.

Why not buy a wall wart with the required output? It will be made to be ungrounded and all the energized parts will be enclosed by the maker so you won't need to worry. By the way, please don't pay attention to phil allison. He is probably in need of professional help but instead spends his time trying to rile up anybody he can online. Just like when CB radios were a big craze and all sorts of shy whackos would get their hands on a radio and broadcast all sorts of stuff pretending to be something or someone they were not. ERS

I've never noticed his technical advice to be incorrect. Of course, he doesn't give technical advice as often as he spews abuse.

"Al in Dallas" <

YOUR post IS 10% abuse as it is not specific t any matter and presents your erroneous conclusion as fact.

....... Phil

It sounds like it's probably an isolated supply. The only Earth ground you should need should be the frame of the supply - i.e., any metal that a person could touch.

If your device needs a real earth ground, then just tie them together at one common point.

Otherwise, there should be no problem using it - imagine a 2-prong wall wart, for example.

Good Luck! Rich