If you can only insulate active or neutral, which should you choose?

Does it matter? Is it important? Is one better than the other?

  • \$\begingroup\$ Is neutral connected to ground ? If so, where in the circuit is that connection ? \$\endgroup\$
    – AJN
    Jul 25, 2020 at 15:42
  • \$\begingroup\$ what is active? \$\endgroup\$ Jul 25, 2020 at 15:55
  • 1
    \$\begingroup\$ In Australia, "active" means "live" or "phase" or whatever the term happens to be for the other wire than "neutral". \$\endgroup\$
    – Justme
    Jul 25, 2020 at 15:57
  • 1
    \$\begingroup\$ Do you mean "isolate" instead of "insulate"? isolate verb /ˈʌɪsəleɪt/ cause (a person or place) to be or remain alone or apart from others. insulate /ˈɪnsjʊleɪt/ verb protect (something) by interposing material that prevents the loss of heat or the intrusion of sound (or, in this case, electrical current). \$\endgroup\$
    – Transistor
    Jul 25, 2020 at 16:23
  • \$\begingroup\$ In general you should insulate both, but there are some exceptions. what is the context of this question? \$\endgroup\$ Jul 26, 2020 at 0:59

2 Answers 2


If you mean live and neutral AC mains signals then live must be insulated. Neutral is supposed to be at ground potential and thus not a hazard, BUT there are numerous wiring errors and fault conditions that could make a neutral conductor dangerous.

I cannot imagine a design of a product that would not insulate both.

Relying on neutral being at ground potential is a bad idea even if only a hobby thing. Don't do it!

Connecting live to ground (not neutral) should trip your residual current detector (fuse like thing in the electricity panel). So if you were to touch the exposed neutral in any of these fault conditions, the RCD should save you from electrocution, but I wouldn't want to rely on that.

  • 2
    \$\begingroup\$ Good answer. Neutral cannot be trusted to be at a safe voltage, especially with heavy loads like a microwave oven or toaster. At point-of-use it can reach 20 VAC to 30 VAC.+1 \$\endgroup\$
    – user105652
    Jul 25, 2020 at 19:27

The live/phase/active wire. Except that in countries where you can connect the mains plug in any orientation to wall socket, either one of the wires could be the live or neutral, so both.

  • \$\begingroup\$ If the neutral becomes disconnected in the plug, but live is still connected, the neutral conductor in the product will be at live potential, until you touch it, at least. \$\endgroup\$ Jul 25, 2020 at 21:32
  • \$\begingroup\$ Good addition. But, given that you have to choose only one (which is a very very bad idea for many reasons), you have to choose one. \$\endgroup\$
    – Justme
    Jul 25, 2020 at 21:39
  • \$\begingroup\$ No, you choose not to do whatever mad thing you were going to do ⚡😜 \$\endgroup\$ Jul 26, 2020 at 20:35

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