Replacing a bulky grounded cable with a not grounded cable

Hi,

On a laptop, how can you replace a bulky grounded cable with a not grounded cable ?

On the photo, you can see: at the bottom the power adapter for my new laptop (a bulky grounded cable) and at the top the power adapter for my old laptop (a not grounded cable).


I want to use the not grounded cable from my old laptop on my new laptop. I need to do this for 2 reasons:
1/ I am often going to Switzerland and I cannot plug the grounded cable in the swiss power sockets directly (but you can plug the not grounded cable in the swiss power socket directly). I had no problem with my old laptop in Switzerland.
2/ The not grounded cable is not less bulky

Regards, Chris

 

You can, but you shouldn't.

The notebook has been designed that way (electrically) and simply changing the plug will give you more problems than you wish for.

 

In the US, at least, hardware stores sell adapters that allow you to plug in a grounded plug into a non-grounded plug (the grounding cable is split and you can connect it manually to a grounding source, in theory. Most people I see who use them don't do that). Maybe there's something similar for european plugs. I never have issues using these adapters - although it's not particularly safe or recommended (especially long-term use).

Cheater plug - Wikipedia, the free encyclopedia

 

hellblazer970,

thanks for giving a good example of the "you can, but you shouldn't" option.

 

The ground wire is really to protect the user from being shocked or worse case electrocuted (because you become the ground). The electronics still have a path to ground (or return path) through the neutral wire.

 

Neutral wire does not equal ground.

 

How can I insert the none grounded plug instead of the grounded plug into my laptop charger?

​

Replacing the grounded plug by a none grounded plug has no real impact because:

- everything always worked perfectly with my former laptop
- and my new laptop needs less power than my old laptop !

- my old laptop needed: 90 W (19.5 V and 4.62 A)

​

- my new laptop need: 65 W (19 V and 3.42 A)

​

 

I'm dead certain that an adapter that matches local power/grounding requirements can be found at any local hardware store while in Switzerland.

Well, is there an OEM version of the same adapter without the 3-prong plug? There are manufacturers who offer both versions (sometimes depending on locality) ...so if the bulkiness is that much of an issue, that option stands as something to be looked into.

Good luck.

 

I do it all the time when I'm travelling. Firstly I want the lighter and less bulky 2-core cable and secondly I can't be sure that the ground pin in the sockets is properly earthed. If it isn't then it can carry a significant voltage if there is leakage from other connected appliances.

In the UK I can get a useful adapter to connect a 2 core cable with Fig-8 plug to the cloverleaf socket on the PSU. A few years ago a lot more PSUs were sold with Fig-8 connectors. I suspect that the trend towaards providing grounded PSUs (even though I thought they were double insulated) is so that single product can satisfy all the diverse electrical regulations that prevail around the globe.

A further benefit of not having a grounded PSU is that there's no risk of creating a ground loop if connected to other grounded equipment.

John

 

With this, your laptop charger is even more bulkier and I am sure that I will forget this adapter (or even loose it). So it is not a good option.

I am using a Vizio laptop and unfortunately I have not seen an OEM version matching the Vizio plug:

That's a good idea, I am going to look at this Fig-8/cloverleaf adapter.
I was thinking about tweaking the figure 8 plug in order to insert it into the cloverleaf socket, do you know if someone has already done that? (it is the method providing the least bulky laptop charger )

 

I'm sure I've done that. I think had cut out some of the plastic between the two pins of the Fig-8 plug (not enough to expose the metal!) but an alternative may be to cut out a bit of the plastic in the cloverleaf socket where it conflicts with the Fig-8 plug. Either way, proceed a bit at a time until the plug will go in. In fact, just to confirm my hypothesis I've just spent a couple of minutes attacking the cloverleaf socket and now a Fig-8 plug will fit (and the PSU works ).

As an aside, if your notebook has a non-standard PSU then I would recommend taking a spare PSU. It's unlikely that you would need it but it can be somewhat inconvenient should have only one PSU and it decides to die. I had that happen to me about 12 years ago and i had to use an old computer for a couple of months until I got home and could get the PSU replaced.

John

PS: Having got the PSU running on an ungrounded supply it would be prudent to check for any leakage voltage on the metal parts of the computer using a mains testing screwdriver. I've just tested my E7440 with an old PA-12 (5-6 years) PSU which has a Fig-8 connector and that PSU leaks some voltage which I could feel and showed up on the testing screwdriver.

 

That's great ! What did you use to cut the plastic between the 2 pins of the Fig-8 ?
Did you use something a Stanley knife like this :

I prefer to cut the Fig-8 plug as you did rather than the cloverleaf socket because the cloverleaf is located directly on the power adapter.

You are right, I am going to order a new power supply for my laptop.

 

I can't remember what I used but I would recommend initially using a saw because there's greater control over the direction and how much you cut. The Stanley knife or similar can then be used to slice away the plastic to widen the saw cut.

John

 

I have just cut a Figure 8 cable to insert it into the cloverleaf socket, it works !
And the plug stays solidly in the socket, that's great !

What should I precisely do to check this? I am not knowledgeable at electricity.

 

Honestly, I fear for your equipment and for your life.

 

Can you please develop your point?

 

The grounding wire is there to prevent electric shock to the consumer. However, in applications where there is sufficient insulation between the consumer and the internal electronics, the third wire is not necessary. I hate laptop power supplies with 3 prongs. The cables are much more bulky. Also, I would need larger and heavier adapters to use them overseas.

Years ago I was in a bind and had to snap off the third prong. No issues. I've never used a 3 prong power adapter since.

It is tiller's way or the highway.

 

yep ive got the same thing goin on here, i just used a pair of wire cutters to cut between the figure 8.



the thing you have to keep in mind is NOT ALL "FIGURE 8" PLUGS WILL WORK. this should be obvious lol but i mean you cant use a hard plastic kind because it will crack the whole thing, do NOT attempt to use one thats cracked.

 

I'm referring to using one of these to check any exposed metal parts for any high voltage leakage. You touch any metal part with the tip of the screwdriver and put your finger on the other end. If high voltage is present the neon light glows. [Note that the current involved is very low so you will not get any shock.]

John

 

Thanks for your posts, it confirms that I am not the only person being annoying by the bulky grounded cables and the fact that you can not use directly when abroad.

Are there different kind of Figure 8 plastic cables?
I think mine in made of hard plastic (!). It is a Hama Mains Lead, Euro plug - 2-pin socket.

What do you mean by "crack" ?
Here is how my Figure-8 plug looks like after the tweak: there is like a "crack" between the 2 pin

I have no mains tester screwdriver but a friend has a multimeter, so will try to get it to test. I suppose the corresponding test would be to touch a metal part of my laptop and the ground pin of a power plug and see the voltage difference, is that correct?

 

The neon light in the screwdriver uses a very low current compared to a multimeter.

Sometimes there is some power leakage within the PSU which can raise the voltage of the notebook above ground and the multimeter would drain this floating voltage whereas the neon light will illuminate.

The ultimate test is to run your fingers over the notebook surfaces. If you get a "rough" feeling (it's hard to describe) that isn't there normally then you may have a floating voltage problem. If it a bad tingling in the fingers then maybe the PSU is leaking too much.

Voltage leakage seems to vary between PSUs - I've tested some Dell PSUs with ungrounded supplies and the older ones are worse than the newer ones.

John

 

Hi,
I have tested with the multimeter and couldn't see anything as you said.
When touching the laptop, I don't have any special feeling compared to when I use the grounded power cable.

As I am not very knowledgeable about electricity and neon testing screwdriver/multimeter, so I have looked a bit on the Internet for info, and I have found this: https://www.youtube.com/watch?v=wLAJ-keFmpk . I am not fully understanding this, but he seems to warn people using neon testing screwdriver for high voltage. What you talked about is low voltage so his warning does not apply to what you said

 

Interesting video where I suspect that he swapped around the other end of the brown (live) and blue (neutral) wires so sometimes the brown in the terminal block wasn't live but the blue one would be. If using one of those screwdrivers then test every terminal to see what is live, not just the one that should be. In fact, his recommended testing method has a big flaw: if there's a break (due to fault or switch) in the neutral circuit then his big light won't shine whereas the little testers would.

Anyway, he demonstrates the operating principles of the screwdriver and my point is that with some ungrounded PSUs the computer can have a voltage that the screwdriver would detect (if placed against a metal part or just test the outer part of the power plug). I've not figured out why some PSUs are better than others in terms of voltage leakage. If the PSU is grounded then that leakage is wasted power so maybe newer PSUs which are meant to be more power efficient are less likely to leak electricity. (We normally associate leakage with dripping plumbing ).

If you are getting no funny feelings in your fingers then that's a good sign although the ultimate test would be bare feet on a concrete floor when your body becomes a more effective conductor.

John

 

When you second guess (by defeating) what the manufacturers design safety has been decided upon (electrical design choice, heavily influenced by local regulations and wiring standards) combined with lack of knowledge of such things... that is my fear.


Everyone else that is suggesting/recommending differently may be empirically correct for 99.999% of all situations out there.

But do you really want to be in the possible 0.001% that proves them wrong? (For yourself or for your equipment/household/family)?


I have just enough sense/background in these things that I don't try to retro design (anymore). But I may have simply been lucky up to now (unlike an uncle that many, many years back was electrocuted (fatally) by badly grounded equipment (heavy duty machinery).


All I'm saying is where safety is concerned; don't try to outguess the manufacturer. Rule number one.


Good luck.

 

But if the bad grounding is due to the ground wire in the socket not actually being connected to proper ground then one piece of faulty connected equipment can cause all the other equipment on the circuit that uses a ground connection to go live.

In that situation one is better off not using the ground pin in the socket. I've encountered that problem on my travels to places where electrical wiring and standards are not as good as at home.

John

 

no thats fine. there are some that will almost shatter completely if you try to cut it.