Almost electrocuted by ATX power supply

I just plug ghe ATX power supply to an outlet with no ground wire.
During a print i acidentally touch the atx power supply then i got electric shock

Just a warning to all do not leave ground wire floating.
Btw. My power is the 550w supplyed in the kit

Metal cased switch mode power supplies should never be used un-grounded.

Different with plastic cased double insulated ones.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Quote
Chaisaeng
I just plug ghe ATX power supply to an outlet with no ground wire.
During a print i acidentally touch the atx power supply then i got electric shock

Just a warning to all do not leave ground wire floating.
Btw. My power is the 550w supplyed in the kit

Yes, that is quite correct behaviour. Most switchmode PSUs have mains filters that contain small bypass capacitors from both mains wires to the earth lead - and the metal case is also connected to that earth. Thus in countries where one side of the mains (neutral wire) is connected to physical earth, the case will float at about half mains voltage with respect to physical earth via the potential divider created by the two capacitors - which is sufficient to feel through dry skin with mains voltages much above 100V if your body is reasonably well earthed.

Which is the reason why PSUs should never be operated without an earth connection when the mains has one leg earthed unless they carry the "double-insulated" symbol.

The case earth is not usually connected to any of the low-voltage output wires, and so the mains voltage will not be "carried forward" to other equipment - meaning that as an alternative you can put the PSU inside an insulated enclosure (but ensure it has air vents for cooling).

Dave
(#106)