Bringing USA desktop to Japan. Questions about power, grounding, surge

[Lesca]

I'm in Japan and plan to have my desktop shipped over soon. American outlets are 120 V, but in Japan they're only 100 V.
My PSU is the Cooler Master Hyper 212 Pro.
It's rated for 100-240 V so it should work, but as a novice in computer I just wonder if there is some hit to performance or if the change in voltage affects anything really. Does it?

Also, there is pretty much no grounding here. Would using some 3-to-2 cheater thing cause any issues, aside from the danger of not being grounded? I mean, some things have grounding in the form of these little green/yellow wires,like this:

However, theyre pretty much only for big appliances like refrigerators, washers etc, and because of that the only outlets with sockets for these little grounded...things are in the kitchen or laundry room or whatever. 95% of outlets are just 2-prong sockets:

Examples of plugs I'm considering:
Shockshield Yellow Portable GFCI Plug with Surge Protection
and this...

As I understand it, the third ground prong is just for grounding and not related to power supply. On a semi-related note, surge protectors pretty much must have grounding right?

 

[Someone Somewhere]

You need a ground for a computer power supply. It's both for safety and for noise reduction.

Other than the grounding issue, it should work fine on 100V - the difference is negligible, given that local distribution normally only stays within about 10% of spec.

 

[Lesca]

You need a ground for a computer power supply. It's both for safety and for noise reduction.

Other than the grounding issue, it should work fine on 100V - the difference is negligible, given that local distribution normally only stays within about 10% of spec.

If say that pictured powerstrip I posted is in fact a surge protector (I'm not great at Japanese, yet), and I put US grounded things into it and I were somehow able to ground it here in Japan, by getting a special outlet or whatever, it would be fine? To tell the truth I'm also looking to get a US made amplifier for headphones that would be grounded, so I can imagine it must be important to make sure that is grounded.


Also, I'm trying to understand perfectly and this will sound stupid but regarding grounding,
power comes through the neutral and hot prongs of a plug only right?
Ground prongs/plugs are ONLY for grounding excess charge?
The only thing lost without the ground is safety right, not lost power input or something silly?

 

[tsnor]

1. You did an excellent job researching this.
2. Ground only carries serious current when there is a major failure, however ground is used all the time. Google "ground loop problems" and "50/60 cycle hum".
3. Yes you really really want it grounded.
4. GFCI on the power strip is a major plus.

This ref says that Japan is 50 cycles per second in some places and 60 cycles per second in others. "...** Although the mains voltage in Japan is the same everywhere, the frequency differs from region to region. Eastern Japan uses predominantly 50 Hz (Tokyo, Kawasaki, Sapporo, Yokohoma, Sendai), whereas Western Japan prefers 60 Hz (Osaka, Kyoto, Nagoya, Hiroshima)...." https://www.quantumbalancing.com/worldelectricity/electricityif.htm 50 Cycles/sec will mess up your AC powered clock (time will be SLOWer at 50 than 60), but not hurt your PC or your stereo.

Some stereo amps/receivers have a large power draw when turned on. The 100V vs 120 will increase the amps there. A headphone only amp will not be a problem. If you are bringing a 7 channel by 100w amp with a 1000W UL tag consider leaving it at home and going for a lower power amp. If the wiring is "suspect" you may end up blowing a fuse/ circuit breaker.

GL

 

[Someone Somewhere]

AC is tricky. Under normal conditions, the real power at 50/60Hz is only supplied via the line/neutral connections. However, reactive power and high frequency noise is often coupled down the ground wire. Leaving this floating will lead to the ground (and everything grounded, like your case) being live at half line voltage, plus the high frequency noise will likely wreak havoc on anything with poor shielding plugged into the same circuit.

 

[Lesca]

Since grounding seems to be an impossibility here in Japan, what if I just bought Japanese PSU here in Japan?

If its like ones in the US or my old one, it will operate across most voltages and frequencies, but would it be compatible with the other computer hardware? Would it send too little power to the motherboard, gpu, etc?

I don't imagine any connecter compatibility problems. Motherboards, gpus, cooling systems, etc have the same connector pins/plugs worldwide?

 

[Someone Somewhere]

I don't think there are any Japan-specific PSUs. The only regional differences are the power cord in the box, and sometimes a 230V-only PSU.

A quick google shows that you are meant to hardwire the ground wire, to an exposed terminal on the plug:

 

[Lesca]

Yes but unfortunately such terminals only exist on outlets near the refrigerator, washing machine, or air conditioner, obviously being used by them. They aren't on any other normal outlet. The power strip I took a picture above doesn't appear to have GFCI due to the ground wire (they expect you to ground that, in the kitchen I guess . But then I can't plug in the fridge or air conditioner or whatever I use, because the input on such a strip isn't for little Japanese ground wires).

I've been suggested to try a UPS and I've seen gfci adapter plugs suggested, the latter of whose output plugs are 3-pronged so durr. I need to research these a bit more. Or maybe I really should just buy a psu here. Some parts of Japan are 50Hz instead of 60Hz, plus the voltage difference. Since my psu is rated 100-240 V and like 47-63 Hz, it seems like the only problem is the grounding, but
Grounding my psu appears to be impossible. Aside from safety, you mentioned "noise" before. What did you mean by that? You're the only one I've talked to whose mentioned it.

 

[Someone Somewhere]

UPS has no effect. Neither, because I'm sure this will be mentioned, would a voltage regulator.

A GFCI/RCD with the ground tied to neutral on the supply side would be acceptable, as it would prevent ground from floating. This is essentially what happens in most switchboards.

When you have a stretch of wire with only high-impedance connections to a high-frequency signal (like a switchmode power supply), it acts as an antenna. And messes up stuff around it. It may also radiate back down the power lines if the filtering in the PSU is imperfect. Amongst other things, this could lead to hissing in audio equipment (especially radios).

Also, pull one of the outlets from the wall and see if there's three-core wiring behind it. If so, you should be able to get an electrician to swap out the faceplates pretty easily. I'm not sure what Japan's laws are on DIY electrical work.

 

[Lesca]

When you have a stretch of wire with only high-impedance connections to a high-frequency signal (like a switchmode power supply), it acts as an antenna. And messes up stuff around it. It may also radiate back down the power lines if the filtering in the PSU is imperfect. Amongst other things, this could lead to hissing in audio equipment (especially radios).

So would using a GFCI/RCD or even a japanese psu prevent those issues?


I took the faceplate off the outlet to reveal not much more:

And yeah this is pretty much the only outlet in the entire room

Unfortunately I don't have a screwdriver to go any deeper. Assuming it can't be done, either because it's not three-core or grounded or whatever or because I can't change them, my choices are either use a GFCI/RCD, get a psu here, or just live life on the edge with an adapter right?

 

[Someone Somewhere]

As stated earlier, there are no Japanese-specific PSUs, and the fundamental design of the grounding & signalling systems in PCs prevents use of ungrounded supplies.

GFCI is my pick. But see if you can get a screwdriver.

 

[Lesca]

Double posting,

the air conditioner plug only has 1 input instead of 2, but has the japanese ground, obviously being used by the air conditioner. And this shit is like 2 feet from the ceiling. I could use the powerstrip above, and put its japanese grounded plug and the air conditioning plug into a japanese grounded powerstrip which i could plug into that 8foot high outlet. Or not use the AC/heater and have a power strip hanging from my wall, unless I can find a simple 3-prong plug to japanese ground plug adapter and have my desktop hanging from the wall

 

[Lesca]

As stated earlier, there are no Japanese-specific PSUs, and the fundamental design of the grounding & signalling systems in PCs prevents use of ungrounded supplies.

GFCI is my pick. But see if you can get a screwdriver.

What I've read is they extra-insulate their electronics so theres less risk of shock, and obviously people have computers in Japan so I imagine their psu are ungrounded but made safe due to the lack of common grounding

 

[Someone Somewhere]

That only applies to some devices, and TBH most devices outside Japan are like that too - look at any DVD player.

Computers aren't like this; the motherboard ground plane is ALWAYS directly connected to all external metal panels, or cables.

The PSU has a line filter with capacitors to ground from both line and neutral. This means that the case will float at half line voltage. Devices without a ground don't do this; they have complete electrical isolation, usually through an isolating transformer.

 

[Lesca]

Outside of Japan maybe computers arent like that, but considering the lack of means of grounding I imagine they do something like it. I'll check out desktops next time I go to an internet cafe.

So a GFCI will protect me from shock but does it solve those other issues like potential noise/hiss for audio equipment you mentioned? What form of GFCI are you recommending? An adapter? The wall outlet thing? I hear the portable adapters are shaky and must be checked often

 

[Lesca]

Just as an update, the desktops at my work place are indeed grounded, but the most baffling thing is that they are three-prong plugs and sockets like America, not the standard Japanese yellow/green cable. How or why the outlet there is a three prong hole is beyond me. I have never seen one elsewhere.

 

[Someone Somewhere]

I don't know where you get the idea that there is a difference internationally between computers. There isn't.

If the GFCI connects neutral and ground together on the supply side, it should fix all the potential problems.

Ideally, I'd suggest getting a screwdriver and checking for a ground behind the outlet. Failing that, I suspect you can get outlets with a GFCI built in - I know you can for Aus/NZ sockets.

 

[Lesca]

I got the idea from the fact that many other things are different, including the monitors here whose ground is the little green/yellow wire (of which I'm not using btw)

 

[Someone Somewhere]

That's just the plug on the end of the cable, not the device itself.

Your monitors should be grounded too...

 

[Lesca]

Ok so I got the cover off. What am I looking for?

There are four wires coming out, one for each slot I presume.

So there is no earth after all?

 

[Someone Somewhere]

Yeah, no earth. Damn.