As above, what are the disadvantages, risks and dangers involved in modding a class II switch mode power supply i.e. a double insulated laptop charger that is ungrounded to have the dc- output shorted directly to earth?

I know this question has been asked countless times before here, but I did not feel that there was a satisfactory conclusion.

Some of the threads I have reading with more elaborate answers are listed:

How to safely ground a switching power supply with floating outputs?

What does the Y capacitor in a SMPS do?

What I gather now is that what the mod essentially does is bypassing the y-capacitor and I will probably lose all of the EMI insulation class II designs provide. My primary concern here, though, is safety, not just in normal operation but when a fault occurs e.g. loose/frayed wires, shorts.

I may be very wrong, so please correct me where I'm totally mistaken.

Not so necessary background information: I want the power supply output dc- to be referenced to earth to stop the tingle/small shock from touching devices with metal casings powered by such power supplies. I have scouted around for grounded power supplies that supply 15V but they are hard to find and expensive.

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    \$\begingroup\$ There is an interesting paragraph in one of the answer in the second question you linked about class 1 PSUs. \$\endgroup\$ – ratchet freak Sep 22 '17 at 14:25
  • \$\begingroup\$ Thanks, I saw it but it is pertaining to a class 1 psu as you mentioned. However, I am looking to short the dc- output of a class 2 power supply to earth (or by any other better means to reference it to earth voltage) and I'm not sure if that recommendation applies to me \$\endgroup\$ – Xbing Sep 23 '17 at 3:20
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    \$\begingroup\$ Shorting one of the legs of a class 2 power supply to ground turns it into a class 1 at the worst. It's still a safe device or it would not be standard practice for desktops. \$\endgroup\$ – ratchet freak Sep 23 '17 at 8:08

It's fine, there will be a slight leakage to earth but that leakage should be much lower than with many class 1 power supplies.

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