Discuss Grounding issues? (causing light shock) in Japan apartment in the Electrical Forum area at ElectriciansForums.net

Reaction score
0
Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:  American Electrical Advice Forum

Hiya,

I live in a pretty old apartment in Japan. There's only one wall in the whole apartment that has a screw to allow to connect a power cable to an earth. I run quite a few electrical devices and I want to earth as many as possible, so i bought a little black power hub (with 5 sockets) which allows for 3 pin connection, and then that plugs into the wall and I screw that to the earth. I failed science though, so I have a few questions!

1. If the power hub is earthed at the wall, will other appliances be earthed as long as i connect them to that power hub? Even with 2 pin connections? Or does every single appliance need to be earthed individually?

2. I don't know if it is safe to plug in 2/3 pin plugs ( unearthed) into a power hub that's earthed at the wall, but it seemed like when I plugged in an extension cord into that power hub, the same very low, continuous electric shock could be felt - just an unsettling phsyical sensation, like a buzzing feeling and distinct disruption of mood. Is that possible - like plugging directly into the earthed power hub would be okay because that's earthed at the wall, but plugging an amp into an extension cable that feeds into that earthed power hub is just one degree too far from the earth or something and thus still a shock hazard? I'm sorry I'm not more scientifically literate (adhd had me flunking all sciences and math!)

3. regarding electric shocks, I'm mainly noticing like an unsettling feeling and my heart rate racing a bit whenever I plug in anything over 100w to a white extension cable (with 6 unearthed ports, that isn't connected to the earth on the wall). I obviously don't want that to happen, but it's happened now with 2 amps that I plugged into a separate extension cable that wasn't earthed. Is that likely a fault with that particular extension cable? Or can I just not afford to plug anything in to a wall that doesn't connect to the one earthed port in my house?

4. For my safety I will desist from using any 100+ watt amps for the time being, the unearthed it was always fine with a 45w speaker, so I wonder if my old apartment is just failing to provide safe current unearthed, or whether that the white extension cable (with 6 unearthed ports) is faulty?

5. Is it possible that the individual amps are faulty, or is it too much of a coincidence that they're both over 100w and the only things in my house causing problems? I do have a guitar amp plugged in elsewhere, but again that's only 40 watts. Wondering if my whole apartment is just too old to handle anything going above 100w.

6. Sorry, i'm an idiot, I also just realized ive been using a 7a plug instead of the manual's recommended 10a, could that have created some crazy current feedback loop or something that created a continual very light shock to be dispersed from today's speaker amp?

Thank you so much and I'm sorry for my ignorance and myriad questions!


All the best.

Georgie
 
Last edited:

Lucien Nunes

-
Mentor
Esteemed
Arms
Reaction score
9,960
OK, lots to unravel there.

Yes, older Japanese installations tend to be rather lacking in the earthing department. If you have a socket with an earthing screw and the little adaptor that picks up the earth to a 3-pin socket strip then any 3-pin plug connected to that strip should carry the earth through to the appliance. Even if there are more adaptors, extensions etc, so long as they are properly made with 3-core cable, the earth should go through. Obviously lots of extensions and adaptors introduce weak links and are not to be recommended overall, but if they are electrically sound the earthing should function.

A lot of electronic equipment generates 'leakage current' that does not indicate a fault, but can cause faint tingles that are not harmful. If you brush the back of your hand over a metal surface of an appliance and you feel a 'vibration' or 'buzz', that can be a sign of the very tiniest leakage current, even 100 times less than would induce an actual shock, but you can sense it. It should not 'disrupt your mood!' When the equipment is earthed, that tiny leakage current drains back to the source along the earth wire and you don't feel it. If not earthed, you feel it. More powerful appliances often generate more leakage current, so it is not surprising that larger amplifiers might produce more of a tingle when not earthed. This is not due to the larger power consumption as such and does't indicate overload, just that they produce more leakage. Re. overload, one normal Japanese outlet is usually good for 1500 watts (100V x 15A) although in the case of amplifiers, the input power is greater than the audio output so your '100W amplifiers' might be using 200W from the wall socket. But a couple should not overload one socket.

What can happen, though, if you connect lots of smaller appliances to one socket (the one you think offers you the earth connection) but in reality the earthing to the socket is no good, is that all the leakage current from all of them collects together and can be felt when touching any one of them. So if you have three appliances with 3-pin plugs each leaking one milliamp, connected to the 3-pin power strip, but the strip itself does not connect to earth because the connection to the earthing screw on the wall socket is bad, then you can get three milliamps of leakage 'tingle' off any one of the three appliances because they are all connected together.

7A / 10 plug makes no difference in this context.

Of course, if there is a dangerous fault one of your devices and the casing is fully live, then you might also get a tingle from it, or a more serious electrical shock if you also touch something that is earthed. If the equipment is earthed, then the fault should blow the fuse or trip the circuit breaker. The main hazard of things not being earthed is that this does not happen when there is a fault.

If in doubt, post pics! Perhaps you can get a plug-in socket tester that will show whether the earth is connected? These are not infallible, and can sometimes give false readings. If you consider this, post details of a tester before buying it.
 

Reply to Grounding issues? (causing light shock) in Japan apartment in the Electrical Forum area at ElectriciansForums.net

Electrical News from Electricians Forums and Friends

E
  • Article
Want to become a qualified electrician? Look carefully at the training courses on offer to avoid wasting time and money, is the advice in a new campaign from electrical industry body The Electrotechnical Skills Partnership (TESP). With thousands of searches each year on terms such as...
Replies
49
Views
6K
Marty92
Dan
  • Article
You can now link your account with social media by going to the following page. https://www.electriciansforums.net/account/connected-accounts/ We had this feature some time ago but I removed it when Facebook was found to be selling the data they collected without informing the users of what...
Replies
0
Views
2K
Dan
Dan
  • Article
There was a dodgy advert, typical clickbait, showing "how to save 90% on your electricity bill" which was not the case and it was actually showing some dangerous wiring tactics. Read the actual threads here:- What should be the code for this - C2 or C3 -...
Replies
37
Views
8K
Jurassic Sparks
Jurassic Sparks
James
  • Article
The Go Plus hot tub is being recalled because you could get electrocuted taking a dip, according to press releases from the Chartered Trading Standards Institute (CTSI). An Amazon spokesperson said: "Safety is a top priority at Amazon. "We require all products offered in our store to comply...
Replies
6
Views
3K
Dave Appleby
D
Dan
  • Article
Posted on behalf of @CKI:C.K-Tools Carl Kammerling International Ltd, also known to as ‘CKI’, are the company behind the C.K Tools brand. Founded in Germany in 1904 and with roots stretching back to 1790, we provide a wide range of hand tools, tool storage, power tool accessories and...
Replies
2
Views
4K
telectrix
telectrix

Search Forum

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
Top