ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Japanese 50/60Hz power

At least one place has both 50Hz and 60Hz running down the street. Why? I have NO freaking clue, but I'm sure there was a perfectly good reason 50 years ago that's too difficult to change now. Probably the same reason they split the frequency in the middle of the country.

I'm come across 50Hz 100/200V center-tap for the 100V 50Hz Japanese stuff, and 120/208V (delta and wye obviously fed from separate substations and separate services, I mean, why would you possibly want to feed these from a common switchboard???) in both 50Hz and 60Hz.

Here's the Babelfish translation of one of the above pages, just the section relating to LV utilization:




http://babelfish.yahoo.com/translate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http%3A%2F%2Fja.wikipedia.org%2Fwiki%2F%25E9%2585%258D%25E9%259B%25BB&lp=ja_en&btnTrUrl=Translate

BTW, every outlet I've seen in Japan has been US style grounded NEMA. Even for 100V 50Hz. My experiences have been rather limited to hotels that cater to westerners, though.

a different explanation:


found here: http://en.wikipedia.org/wiki/Utility_frequency

I saw plenty of NEMA-like grounded outlets in Japan, they're pretty much identical to their north american counterparts.

I think Japan has had GFCI requirements for much longer, thus there is less concern about 3-pin outlets.

Also, they seem to use mostly double-insulated appliances that don't generally require a ground at all. The only things that did were washing machines and they have the option of a seperate grounding cable that connects onto a lug on the end of the outlet!

It surprised me that they hadn't just adopted US-3pin plugs more widely.

Isn't it the case that the Japanese plugs don't usually have the holes at the end of the blades?

The ones I saw in Japan had holes, I think it's the Chinese plugs that don't.

China has historically used a NEMA like plug, without holes for 220V 50Hz



It causes some interesting problems for US tourists.

Also, Chinese plugs of that type are not polarised, both pins are the same width and you can't always inserts a polarised US plug

They are phasing them out in favour of a plug very similar to the Australian/NZ one.



Note the pin layout is different to the Aussi/NZ setup i.e. it's ground at the top, like the UK/IRL


China 10A


China 16A

Comes in 10A and 16A versions

It seems they're phasing out the 2-blade plugs.

You will also encounter US NEMA or CEE 7/16 (Europlug) 2-pin plugs in China for Class II appliances.

and, in older installations you can encounter either BS546 (old british round pin plugs) or schuko.

BS1363 and modern Schuko can be found in some buildings too!

Also, they have unfused plugs which fit BS1363 sockets. These are designed for use on radial circuits, not UK rings.



However, they're a potentially serious fire hazard if connected to a UK ring circuit should they find their way to the UK.

Is it my eyes, or do the 10A and 16A pictures have there descriptions flip flopped?

must be mine as well

China had historically used parallel NEMA like plug (w/holes) for 220V until national standard modified to a safer design (w/o hole) for 10a 250v in early 90's. PRC are NOT phasing them out (still in national standard & every Class 2 appliance).

BS546 (modified) is "de facto" for earthed appliance in the Delta area (next to Hong Kong, Macao) b4 90's. Although not to national standard, some ppl still prefer their 3-4 kw Air conditioner wired in BS546 15A version.




Unfused 13a plug is "invented" by Taiwanese in late 80's b4 China became world factory !!!