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Static electricity from M2/M2 Pro Mini
- Thread starter hajime
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I have a metal desk, One Less Desk by Heckler Design that’s sadly no longer available for sale. The very first thing I do whenever I sit down for work is to touch the side of my desk on which the keyboard and mouse sit. I developed a habit to never touch the keyboard or mouse first. My Mac Mini M2 Pro is tucked inside the main section of the desk and out of view. I use a wall mounted Ergotron HX monitor arm to support my Dell U3821DW monitor.
There’s no way to change Mini’s plug so you should be as careful as possible.
There’s no way to change Mini’s plug so you should be as careful as possible.
Unlike other electronic components, the Mac mini has an aluminum external casing that is fully grounded. So it acts as a better-than-most paths to ground for the static electricity that comes from you — not the other way around..
That is not the same static discharge, although the reason behind it, electric potential difference, is the same. What you feel is leaking current though the Apple chargers are built to a standard that allows for an extremely low amount that is in no way dangerous.
It happens with any other device with an aluminum housing. It's just that Apple happens to sell a lot of these devices, whereas other manufacturers mainly sell devices with synthetic/plastic devices, such as carbon housings. I have the same thing on an iPad too, again due to the housing, and regardless of whether the charger is from Apple or my trust third party Anker one.
It happens due to how switching power supplies function (again, not just Apple) and in some cases it is actually caused by (older) electrical installations not being up to modern standards in which case there is nothing Apple can do about that, nothing to be done about it in the power supply design.
You might also have noticed that it doesn't always seem to happen, and that is because it can only be felt if you yourself are isolated from ground. You can test that by grounding yourself by touching something like a desktop computer case that is grounded via a three prong power connector or a radiator.
It's always been this way with really any devices made with aluminum housings using switching power supplies, for example it happened on unibody Macbooks over a decade ago.
It's in no way dangerous as Mac chargers are made to safety standards that limit them to exposing 25V DC at the most, and at such low voltages not enough current can flow for it to be harmful in any way as the electrical resistance of your body is too high at such low voltages to let any current flow. Voltage, resistance and current are linked in that way. It's also why safety warnings always say not to use devices near water or in the bathroom. Wet skin has reduced electical resistance, which allows for more current to flow at the same voltage.
Oh right. Well that's a problem then. If neither you nor the equipment can be grounded, then this can always happen with modern switching power supplies (i.e. literally all power supplies in existence now). The only workaround to prevent it is to not touch anything other than plastic, and the actual solution would be to bring the house electrical installation up to code.
Especially since that means all devices in your home that require a three prong plug won't be safe to use. For example if you have an electrical oven that develops a fault such as a wire coming lose and making contact with the metal surface of the oven, no breaker would flip and if you touch the oven you'd get a life threatening electric shock.
If a device can be used with a 2 prong plug then it is safe to be used without grounding, because it won't have any exposed metal parts that you could possibly touch. Hence my example with the oven as that will have exposed metal parts. And if anyone gets injured from this you can bet no insurance will cover it because not keeping such an electric installation unfixed is gross negligence.
Because there is no need for it. You don't need to continously touch your Mini to use it. It wouldn't improve safety either. And for Macbooks there is a grounded cable as an option. And most of the time it doesn't happen anyways.
Thank you for the explanation, but how to solve this? The current is very strong. And I live in an old house with no grounding at all.
An electrician needs to check the installation, they'll have both the equipment and knowledge to recommend solutions.