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I bought the following switch which I would like to control the AC power (230V 50Hz) to an AC/DC converter with. This switch only permits one terminal to connect/disconnect, meaning I could control whether or not the Live wire is connected to the converter or not. But I cannot control if the Neutral wire is connected/not connected.

Is it safe/functional to keep the Earth and Neutral terminals connected from the power supply to the AC/DC converted while switching on and off the Live wire? Attached is a diagram illustrating this. enter image description here

I ask since the previous designer used a double throw switch, meaning the Neutral and Live wire were connected/disconnected at the same time. Whereas now I'm connecting/disconnecting just the Live wire and I'm not sure if that is rational.

Thanks for your input!

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  • \$\begingroup\$ Should be fine. You may want to ask this type of question in the DIY forum next time. \$\endgroup\$ – mkeith May 24 '18 at 2:58
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Is it safe/functional to keep the Earth and Neutral terminals connected from the power supply to the AC/DC converted while switching on and off the Live wire?

Yes. Not only is this safe, but it's the standard.

Switching neutral is dangerous: if the live side of the switch fails closed, parts of the device may be energized to line voltage while the device is switched off. If the device is plugged into other powered devices, it may even end up powering itself through the other device's ground.

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  • \$\begingroup\$ How does "powering itself through the other device's ground" work? There shouldn't be any circuit between either device's AC side and ground, or that would be a ground fault, no? \$\endgroup\$ – Kevin Reid May 24 '18 at 0:44
  • \$\begingroup\$ @KevinReid This is in the case where the live side of the switch has failed closed. (Or is still closed for a moment after the neutral side has already opened.) \$\endgroup\$ – duskwuff May 24 '18 at 0:47
  • \$\begingroup\$ Pretty sure double pole switches are OK. \$\endgroup\$ – mkeith May 24 '18 at 3:01
  • \$\begingroup\$ Even if the live side is not switched there should be no path for current which includes ground. (To be clear, I'm not arguing against switching the live side preferentially.) \$\endgroup\$ – Kevin Reid May 24 '18 at 3:03
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    \$\begingroup\$ Many countries have plugs that can be inserted either way so you cannot say that one specific wire is hot, either could be hot. For this case, to make sure the hot is switched for safety, you must interrupt both wires with the switch. \$\endgroup\$ – DoxyLover May 24 '18 at 11:15

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