Here's your periodic reminder about how cursed Japanese wiring is.

Posted 2023-08-08 | Back to blog index

Here's your periodic reminder about how cursed Japanese wiring is.

This is an official, standard Apple power cable that shipped with a MacBook.

A mains power cord with a two-pronged US-style plug on the end, except there's also a yellow green ground cable sticking out the side of it with a screw-in pitchfork on the end

In case you're curious how you connect that to the wall...

A plug in a wall socket. The outlet has two US-style two-prong outlets, except under them there is a ground screwed with the aforementioned ground wire screwed in

Bouns Round: This power strip, made by a reputable Japanese company, sold at brick and mortar electronics stores, and with PSE (product safety electrical) marking

A power strip, with indents on the outside plastic to fit a grounding prong so you can plug in grounded plugs into the ungrounded power strip

And you can be sure this is not some design mistake, it is literally advertised for this purpose!

They're still for sale, totally legally. Apparently they've been so popular that since I bought mine, they've also introduced a range with built-in USB ports!

Advertising image for the cursed power strip, with a circle showing a grounded plug with it's ground prong just hanging out and the text 3Pプラグも差せる! Another advertising image showing a grounded plug and the text 3Pプラグ専用タップを使わずに差せる!There is an asterisk in the corner: アースの接続はできません。

Update on 2023-08-09:

I recalled a few more fantastically handy Japanese power strips

A power strip with all the US-style pins but they are all the same spacing from each other so you don't know if you're connecting to live or neutral A power strip with just two long slots

Update on 2023-09-07:

I just found the motherlode of ground pin adapter plugs!

A plastic bin full of three-pin grounded plug to 2-pin+ground wire adapters

Update on 2023-09-29:

Look what just showed up in the mail!

A power strip that is just two long slots. It is in its brand new unopened packaging. There is Japanese text on the packaging, including text that says in big red letters “internal safety breaker” The rear of the package with safety notes差込口にクリップなどの細いものを差し込まないでください。差込口にプラグを差したまま、差込口内を移動させないでください。タコ足配線は、しないでください。差込みプラグを斜めに差し込まないでください。万一差し込んでしまった場合は、絶対にプラグの刃の部分にお手を触れないでください。

It's surprisingly hard to push in, and the plug won't slide back and forth once you have.


A plug half-plugged into the power strip, measuring 100V off the half-exposed pins

It least it DOES do what is advertised and is really handy for odd-shaped power bricks!

A power strip with 5 different AC/DC adapters all with different sizes snugly butted up against each other

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