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Joined: Aug 2008
Posts: 61
andey Offline OP
Hi Forum,

anyone knows about Japanese electrical?
They have 100V standard outlets, often 2-pole only.
And 200V outlets, 3-pole.

I need to know if GFCI, RCD etc. are used for the 200V 15A or not.
And if yes, what trip current is usual.

I need to send an industrial device down there with some leakage current from the line filters. Need to evaluate if it will work or not.

Any ideas?

Last edited by andey; 10/20/21 07:11 AM.
Joined: Jul 2002
Posts: 8,412
Likes: 3
Hi Andreas,
Japan is a funny place, voltage-wise, in that it uses a 100/200VAC local distrbution system, 100VAC is the
single phase voltage and 200VAC is the 3-Phase Star based system.

Let me quote this:
Frequency is either 50Hz (east Japan including Tokyo, Sendai and Sapporo)
or 60Hz (west Japan including Nagoya, Osaka, Takamatsu, Hiroshima, Fukuoka, Naha),
depending on power companies.

# For home appliances
: Single-phase 3-wire,
100V (using live and neutral wires) / 200V (using live and live wires).
: Most home appliances are designed only for 100V.
# For factory uses
: 3-phase 3-wire, 200V.

So we have 3 phase, 3 wire, which suggests Delta?
Or it could be 2 phases plus a neutral at 180° wired as Star.

What sort of equipment is this?
Does it matter if the frequency of the supply is 50 or 60 Hz?

I look forward to your reply.

Mike T.

Joined: Dec 2001
Posts: 2,495
A third option is star with no neutral supplied to the load, which was once a common system in many European countries, 127/220 V. The centre point of the transformer was earthed but the distribution network had no neutral or PEN conductor, resulting in a TT system. Berlin had a 127/220 V TN-S system.

Most single-phase loads don't care about the supply arrangement as long as the potential difference is right, so apart from fusing and switching it doesn't matter whether you have one line and one neutral conductor or two lines.

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