View Full Version : earthing electrical appliances
2003-01-14, 05:25 AM
I am about to move to Osaka from Britain. I have a question about earthing the electrical appliances that I'll be bringing with me.
I want to bring a bunch of small electrical/electronic things over to save buying new in Japan. I'll need to buy a step-up transformer to run these gadgets, and the (British) electrician who's supplying this says the transformer must be earthed.
Japanese power sockets, though, are two-pin only. My question(s) then is (are):
1. Are appliances earthed in Japan?
2. How to connect three-wire British goods to two-pin Japanese power safely?
I'd be most grateful if any British residents in Japan can clear this matter up for me.
2003-01-14, 10:29 AM
1) Generally no, though washing machines are sometimes grounded to a water pipe. When I asked an "electrician", he said it's only 100v. He obviously knew nothing of current and resistance.
2) Ignore the ground. Unless you are putting together a recording studio with rack equipment and worrying about earth loops, it will have no effect.
I have been running electrical and electronic equipment for 15 years, a mixture of 100/ 110/ 220/ 240 v here, all ungrounded. Only once came across an issue with a non-referenced floating voltage, which needed grounding to work. (That was some British comms gear)
HOWEVER, I run all electronic gear through Power Supply Distributors, which have a built-in spike filter, as supplies here are susceptible to spikes when heavy loads are switched on.
Do you really neeed to bring that stuff with you? Maybe better to get it here? Osaka is also 60Hz, Tokyo and the UK are 50Hz, so items based on phase such as timers may run quicker.
2003-01-14, 04:20 PM
Dear Yokohama resident,
Thank you very much indeed for kindly replying in such detail. Your reply is most helpful, and throws light on the matter where electrical and electronics shops here - knowing nothing of Japan - have been unable.
Being an ignoramus where these matters are concerned, I have a couple of follow-up questions, please:
1. Step-up transformer #1. All the step-up transformers I can find for Japan here come, naturally, with earthed output (for 3-pin British plugs) and also - mystifyingly - earthed three-pin input. The guy I'm buying from tells me that both two- and three-pin sockets ('konsento') are to be found in Japan. Others tell me only two-pin sockets may be found. When I was last in Japan 10 years ago, I only saw two-pin wall sockets. But 10 years is a long time in Japan, and perhaps things have changed. Please advise!
If only two-pin sockets are to be found, do I then simply stick a two-pin adaptor on the end of the three-pin input?
2. Step-up transformer #2. The guy selling me this is particularly concerned that it be earthed, since the casing is metal, not acrylic. Is this a problem in your view?
3. Is the Power Supply Distributor you refer to the same item as a 'surge protector'?
4. All my British goods run on 50 Hz. Will Osaka 60 Hz be a problem? I am afraid I do not know what is meant by 'items based on phase'. Which common domestic items (type-writer, CD player etc) would be affected?
I am, incidentally, shipping stuff out - because this works out cheaper, I calculate, than buying new in Japan.
With many thanks for your time and generous help,
2003-01-14, 05:08 PM
1) Some modern Japanese places have 3 pin, but most are 2. Even big event and conference venues still have 2 pin C-blocks for 300A phased supplies where you jump phases for 220V. Some modern offices and IT outlets use them, but domestic is nearly all 2 pin, except for heavy items such as air-conditioners.
Generally Japanese places are poorly wired, minimum spec cables, and electricians are near useless. I just had to redo local Panasonic "engineer's" attempt to wire in a satellite dish, and fibre-optic cable engineer did not know how to diagnose wall fittings and structure.
2) All my step-ups are UK made, metal cased, up to to 1500W size, with Mk 3 square pin socket on one side, and a replacement 2 pin plug hard soldered on the other. Or stick a 3>2 adaptor on. Earthwire is usually flying off it.
Don't like Acrylic - fire risk when hot - can be lethal.
Never had a problem, and I use them a lot. May get hot if fully loaded and on for long periods. Use them at no more than 50% capacity for safety.
Your UK rep is rightly cautious, working to a rather higher standard, but 240v does give a bigger kick!
3) Surge protector - same 1 in 6 out.
4) Some turntables, ceramic heaters with timers. (Japanese have dual timing scales for 50 and 60 hz regions).
Always solder the leads in your plugs, gives a better grip, helps prevent cable fraying and shorting. I use lockable 3 pin distribution blocks, whether the earth is used or not. UK-based road crews on tour in Japan have nightmares with underpowered venues, and lighting systems,
Trip Hop (Ms.)