how to make a 2 to 3 prong adapter ground with my 2 prong only outlets

Discussion in 'MacBook Pro' started by Sossity, Nov 5, 2010.

  1. Sossity macrumors 6502a

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    #1
    I have my macbook pro in my bedroom, & a power strip, but all the outlets are 2 prongs. I dont have any knowledge of electrical wiring, so any suggestions on just changing the outlet to 3 prong wont work for now, nor do I have alot of money to hire an electrician.

    I live at home with family, I dont own the house, so I cannot be drilling holes in the wall, running long wires outdoors or doing anything that will blow out our breakers. I need something simple that will not require a major upheaval.

    I read that one can attach a wire to the little metal part of a 2 to 3 prong adapter & run the wire to a pipe.

    the best that I could do would be to attach some sort of wire to the 2 to 3 prong adapters metal piece, & attach or wrap the other end of the wire to something metal in my room, maybe bring in a small piece of pipe & wrap the wire around that. The outlet is awkward to get to, it is behind my desk. Would this work? & how do I do it to avoid shock or circuit blowout? what type of wire could I use?

    right now, I have had the power strip plugged into the 2 to 3 prong adapter with is plugged into the outlet, & it had 2 lights on; one red for not protected, the other green; for grounded, they both glow on at the same time.
     
  2. firestarter, Nov 5, 2010
    Last edited: Nov 5, 2010

    firestarter macrumors 603

    firestarter

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    #2
    Where in the world are you?

    The Apple laptop power supplies are a double insulated design with no earth anyway, so this shouldn't be a big deal.

    If you take the plug off the adapter, you can see a standard 'figure of 8' socket. You should be able to find or buy a 2 pin to figure of 8 lead at any electrical store - just plug this into the adapter.

    [​IMG]

    [​IMG]
     
  3. Sossity, Nov 5, 2010
    Last edited: Nov 5, 2010

    Sossity thread starter macrumors 6502a

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    #3
    I am in the USA, & I was referring to a 2 to 3 prong adapter such as one of these; [​IMG]

    because my wall outlets in my bedroom are only 2 prong like the ungrounded outlet with only 2 slots. [​IMG]

    I plug my macbook pro through it's AC power cord into a power strip like this one; [​IMG] along with my external hard drives, into my bedroom wall outlets so I need the surge protector to be grounded. So I have my bedroom wall outlet > 2 to 3 prong adapter > Belkin power strip plugged into the 2 to 3 prong adapter> macbook pro & external USB hub, & external hard drives etc.

    @firestarter, I am not sure what you were talking about, could you post a photo or something?
     
  4. firestarter macrumors 603

    firestarter

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    #4
    Do you need a surge protector? Is the power in your area bad?

    Laptops don't benefit that much from surge protection - they're pretty resilient and obviously have built in battery backup if the power drops out.

    Your MBP is happy working from a 2 pin outlet, and your external drives probably are too. Why not swap out the surge protector for a 2 pin power strip and run everything on 2 pin?
     
  5. Sossity thread starter macrumors 6502a

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    #5

    Yeah, the power is not the best in my neighborhood, the houses are 1950's era old military style housing. I suppose I could do this, but I was under the impression that everything had to be grounded, & 3 prong everything was the only way. We sometimes do have power surges & outages, when there are alot of things running in our home, (fans in the summer) (heaters or hairdryers in the winter), sometimes lights or a fan are on & someone will be running a vacuum cleaner & everything in the house or a section of the house will blow the breaker. The kitchen & bathroom in our home has had the outlets rewired for 3 prong, but my bedroom is still the original 2 prong outlets. It happens maybe 1-4 times time per year. Our house is old, was built in the 1950's. We do have thunderstorms in the winter that have caused power outages. It is just that I have alot invested in my equipment & dont want to lose the mac or any data.

    I also read that people were getting shocks from their macbook pros, the metal or staic or something, & that using the whole AC cord with the 3 prongs would prote4ct against any shocks.
     
  6. firestarter macrumors 603

    firestarter

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    #6
    A surge protector could be useful for your external drives, but less useful for your MBP. Modern peripherals with switch-mode power supplies should be less susceptible to power drops anyway.

    It makes absolutely no difference hooking your MBP to a 3 pin socket. As you can see if you take the plug off the power supply - there are only two connectors in there and the ground connector goes nowhere! This electric shock issue is more likely to be static discharge.

    I think you'd be safer running everything from a 2 pin block rather than bodging together some sort of 3 pin power supply. To make sure you don't have any problems with external disks being fried - make sure you have good backups and make sure all your backups aren't wired up at the same time.
     
  7. Mavimao macrumors 6502a

    Mavimao

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    Lyon, France
    #7
    Um, apple laptop chargers DO have an earth connector. It's the round disk nub that the different official plug adaptors slide into. This is further confirmed by the magsafe connector which has three different connectors: positive, negative and earth.

    I can tell you that if you're using a metal macbook pro, and it's not earthed, that electricity is going to conduct into your body. It's like a strange buzzing feeling. Try this at home: plug your computer into a socket with the two-prong adaptor and slide your finger over the palm rest area. Do the same thing with the 3 prong extension cord. Notice a difference?

    Just to note, this experiment won't work on plastic macbooks since plastic is a poor conductor of electricity.
     
  8. Mavimao macrumors 6502a

    Mavimao

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    #8
    A surge protector doesn't protect you from a drop in electricty, it protects your items from a sudden SURGE of electricity (hence the word, surge). During a lightning storm, if a bolt of lightning hits the mains, all that juice is going to travel through your house and fry all your electronics. Hence a surge protector is more than necessary for your electronics!
     
  9. Phil A. Moderator

    Phil A.

    Staff Member

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    #9
    Yep, that's correct - if the charger has a metal nub then it's earthed. The iPad chargers have a plastic one and are therefore unearthed.

    You have to be careful with the plugs that fit onto these because although you can put the plug off an iPad adapter onto a MacBook Pro adapter it will be unearthed as they have no earth connectors in them (If you look into the slot on the plug or cable, you can clearly see metal strips on the earthed ones: They contact the metal nub and complete the earth circuit)
     
  10. Sossity thread starter macrumors 6502a

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    #10
    I see, so a surge protector would not be much help when the breaker switch get blown in my home?

    how do I get my bedroom 2 prong outlets to be ground with a 2-3 prong adapter, so when I plug in my surge protector it will be ground.
     
  11. Sossity thread starter macrumors 6502a

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    #11

    I have not tried that, that is why I am using the whole macbookpro AC power cord, not just the 2 pin one. Would it make any difference that I use an external apple aluminum keyboard & plastic mouse plugged in via a USB hub?
     
  12. firestarter, Nov 5, 2010
    Last edited: Nov 5, 2010

    firestarter macrumors 603

    firestarter

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    #12
    Nope, the nub is just a mechanical post.

    1/ I just tried it on my Fluke meter - and it's not connected to anything. I believe the PSUs aren't country specific.
    2/ Check out your plug adapter, at least with mine, there's no connection from the earth. Here's the UK one - the sleeve the nub fits into is just plastic - no earth contact:

    [​IMG]

    UK earthing is different from US, as we don't allow our power to completely float from earth (we have neutral and live, and neutral is bound to earth).

    Any tingling is more likely to be a problem with your house electricity supply, not your Mac.

    I know. But running a modern multi-voltage switch mode power supply is more likely to help you deal with peaks and troughs of power (in the OP's example of problems caused by a vacuum cleaner, that's likely to cause a dip as it's switched on and noise while it's on).

    All modern power supplies which are 'CE' stamped already contain inductors etc. to filter out both noise from the mains and any noise coming back out of the appliance. There's not as much of a requirement to run a surge protector these days compared to a few years back.

    Edit:

    That's interesting - and dangerous. What an odd electrical system you Americans have!
     
  13. Mavimao macrumors 6502a

    Mavimao

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    #13
    OK, you just proved what we've just said. Yes, the sleeve is plastic in the small plug adaptors. However, in the extension cords like this one:

    [​IMG]


    ...there is metal inside of the sleeves in those adaptors. This is connected to the ground in the metal nub of the ac adaptor.

    I'm not an electrician and sure as hell have no knowledge of UK electricity supply (although I find the idea of having a fuse in your plugs quite odd and facinating!) I just know from experience in the US and in France where I currently live that my macbook pro conducts electricity if it's not grounded, and it doesn't when it is.
     
  14. AdamRock macrumors 6502a

    AdamRock

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    Toronto
    #15
    you want to cut off the ground prong? bro your going to blow up something sooner or later.
     
  15. Zauberer macrumors regular

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    Oct 7, 2010
    #16
    Go to Home Depot or Walmart and buy a 2to3 prong converter for like $.50.
     
  16. hamlin macrumors regular

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    Ontario, Canada
  17. defender macrumors member

    defender

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    #18
    I have a UK macbook pro and it is definitely earthed. See attached image. If I use an ungrounded outlet or standard figure of eight cable I do get the odd tingle from the laptop. Earth is good. Use it.
     

    Attached Files:

  18. Fishrrman macrumors G3

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    Feb 20, 2009
    #19
    Sossity -
    What kind of heating do you have in the room in which the computer/power outlet is located?

    Large cast-iron radiators?
    Low profile radiators that run along the baseboard?
    Forced-air ventilation with air vents?

    My house was built in 1911 (originally with knob-and-tube wiring!) and it has the same 2-prong outlets. It has hot-water heat with large cast-iron radiators.

    I went to a hardware store and bought a grounding clamp. This attaches to the pipe feeding the radiator, and it has a screw terminal on it.

    I then got some copper wire and a three-prong outlet.

    I replaced the old outlet with the new one (suggest you locate the correct fuse or circuit breaker for this outlet and de-power it first!). I ran the copper ground wire from the screw terminal on the outlet, to the screw connection on the ground clamp. If you need to run the wire any distance (I eventually upgraded a second outlet in the same room), get small tacks and run it along the wall baseboard.

    Once done, I used an "outlet tester" (has 3 lights on it) to check the outlet to see that it was properly connected. You want the "hot" and "neutral" lines corrected properly and not reversed. The circuit tester will indicate this.

    I will _guess_ that it's possible to make the same connection to more modern "low profile" hot water radiators as well (may be necessary to take the cover off).

    If you have forced-air ventilation with the vents on the floor or close to the floor, it _might_ be possible to attach your ground wire to the venting metal, which should give you the ground you're looking for.
     
  19. observer macrumors member

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    Jan 26, 2007
    #20
    It's really quite funny to see Europeans giving advice about US power sockets. Outdated US power sockets.

    The central screw in the 2-prong socket plate, that holds the plastic plate on to the metal housing, is connected to the ground (called earth in UK). Hardware stores have 2-prong to 3-prong adapters with either a wire or a lug to connect onto this screw. Buy one, screw it on, you've got a grounded 3-prong plug.

    It's a good idea to check, though -- some house wiring is weird (and out-of-code), and occasionally the screw doesn't really connect to ground.
     
  20. jlc1978 macrumors 68000

    jlc1978

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    Aug 14, 2009
    #21
    Good surge protectors have a faster response time tongue voltage rise than a breaker; this the provide protection from the start of the surge until a breaker opens.

    To get a ground - unscrew the cover of the outlet. Plug in the 2 to 3 concertos, screw the little round wire into the outlet using the cover screw. Not the best ground but better than none.
     
  21. Blu101, Nov 5, 2010
    Last edited: Nov 5, 2010

    Blu101 macrumors 6502a

    Blu101

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    #22
    Not quite.

    No matter how good power supplies get, you ALWAYS want to fry a surge protector instead of your electronic device for obvious reasons. Even though the power supply inside your electronic device may protect it, it itself can get fried in the process, and many devices don't carry a separate internal power supply anymore, it's incorporated into the main board, so you might not be able to simply replace the fried components.

    Voltage fluctuations are not a concern, your power supply should be able to handle them. It's surges that you need to worry about, and many are too fast for a normal breaker, so for a short amount of time (until the breaker breaks the circuit), the surge will reach your devices and may damage them - in fact, if the surge is fast enough, it can also pass the device's power supply surge protection componet(s) and reach sensitive electronics, before the surge arrest devices can act.

    Noise isn't the concern, it's surges.

    Either way, the CE Mark and all other approvals can never guarantee 100% safety across the globe. Why? For many reasons. There are always counterfeit products that slip into the market, which have markings like CE, UL, etc., except that they are fake - they haven't really been tested, the manufacturer (usually from China) just copied them from authentic products. UL issues warnings all the time when they catch one, usually from small house fires or personal injury caused by these fake products (they usually penetrate retails chains like Walmart and K-Mart - last year there were some Christmas lights that caused fires, etc.).

    Some legitimate OEMs simply don't certify their products correctly. Some may simply throw CE approved components together and sell the assembly as a finished product without testing and certifying the assembly as a whole. Doing it this way does not guarantee electrical safety on an assembly level, because the components are only approved at the component level and have not gone through the proper testing and evaluation for safety on a system level with regards to their end use application.

    And the CE Mark has many Directives which are self-certification based - no mandatory 3rd party testing and certification, like the Low Voltage Directive (general electrical safety for many products and equipment). This means you are relying entirely on the OEM for "safety", which in some cases, means you are relying on one or two people...and so on.

    Product safety approvals are great, but we consumers still want to cover our own butts ;)

    Each region or country has its own definition of "safety" and the means with which to achieve it. If only the whole world could agree on one set of standards lol I think the IEC/IECEx Scheme comes close, it's a global set of standards, but there are still national differences to account for the different schemes and power grids of different countries. Maybe one day we'll get there!
     
  22. vant macrumors 65816

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    Jul 1, 2009
    #23
    This thread is full of info beyond my comprehension.

    What is the purpose of grounding your MBP? I use the 2 prong mostly, I don't bother with the extension (which includes the 3 prong).

    Which country has the best electrical system?
     
  23. Blu101, Nov 5, 2010
    Last edited: Nov 5, 2010

    Blu101 macrumors 6502a

    Blu101

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    #24
    Good explanation here: http://www.epanorama.net/documents/groundloop/why_grounding.html

    I've copied most of it below for easy reading:

    "A Grounding system has three main purposes:


    1. Overvoltage protection
    Lightning, line surges or unintentional contact with higher voltage lines can cause dangerously high voltages to the electrical distribution system wires. Grounding provides an alternative path around the electrical system of your home or workplace minimizes damage from such occurances.


    2. Voltage stabilization
    There are many sources of electricity. Every transformer can be considered a separate source. If there were not a common reference point for all these voltage sources it would be extremely difficult to calculate their relationships to each other. The earth is the most omnipresent conductive surface, and so it was adopted in the very beginnings of electrical deistirution systems as a nearly universal standard for all electric systems.


    3. Current path in order to facilitate the operation of overcurrent devices
    This purpose of grounding is the most important one to understand. Grounding system provides certain level of safety to humans and property in case of equipment damages.


    Grounding operation in electrical distribution network

    The main reason why grounding is used in electrical distribution network is the safety: when all metallic parts in electrical equipments are grounded then if the insulation inside the equipments fails there are no dangerous voltages present in the equipment case. Then the live wire touches the grounded case then the circuit is effectively shorted and fuse will immediatly blow. When the fuse is blown then the dangerous voltages are away.

    The safety is the primary function of grounding. Grounding systems are designed so that they do provide the necessary safety functions. Grounding also have other functions in some applications but the safety should not be compromised in any case. Grounding is quite often used to provide common ground reference potential for all equipments but the existing building grounding systems might not provide good enough ground potential for all equipments which might lead to ground potential difference and ground loop problems which are common problems in computer networks and audio/video systems.


    How electric shock happens

    The "hot" wire is at 120 volts or 230 volts (depends on the mains voltage used in your country) and the other wire is neutral or ground. If a person were to touch the neutral wire only, no shock would result simply because there is no voltage on it. If he were to touch the hot wire only, again nothing would happen to him unless some other part of his body were to become grounded. A person is considered to be grounded if he comes in contact with a water pipe, metal conduit, the neutral or ground wire, or stands barefoot on a concrete floor.

    In other words, neither wire is a shock hazard unless a person is grounded, and then only the hot is a potential shock hazard. Of course, if a person were to touch both wires at the same time, he would be shocked simply because his body is completing connection between "hot" and "ground" wires.

    Grounding in wiring
    Today's modern (US.) mains cable consists of three separate wires: black, white, and green. The green wire is always connected to the large ground pin on the plug, and the other (green) end connected to the chassis of the equipment. The black wire is always considered to be the "hot wire," and as such, is always the leg which is connected to the switch and fuse. The white wire is always the neutral or common wire.

    European coloring is a little bit different. The ground wire is here green wire with yellow stripe. Neutral wire is blue. Live wire in Brown (additional colors for the live wires used in 3 phase systems are black and black with white stripe).

    Any modification of the above 3 wire mains system completely eliminates the protection given by the three wire configuration. The integrity of the separate ground path is also directly related to the quality of the receptacle and the wiring system in the building itself.

    The neutral (grounded conductor) must be solidly connected (bonded) to the home's ground system at the first disconnect (main panel). This keeps large voltage differences from developing between the neutral and ground."

    The one with the most up to date electrical wiring across its lands ;)
     
  24. firestarter macrumors 603

    firestarter

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    #25
    Hmm. Really it depends where you live. Certainly in the UK the power is very high quality and most people neither have nor need a breaker.

    Filtering on the inlet of regular power supplies will arrest short peaks. Often a problem with older houses is brown-outs, and as you say a modern PSU should deal with that.

    Hmm. We're talking specifically about an Apple laptop setup here. I think the PSU will meet CE standards and be deigned to satisfy standards in multiple international regions.

    The design of even a cheap PC doesn't really allow the OEM to mess with the power supply. The PSU is delivered in an enclosed package with the power inlet socket integrated.

    Many products are built using third party 'wall warts' precisely to allow the manufacturer to make use of a pre-approved PSU and save them from getting approval themselves.

    I think your paranoia is unjustified on this one.

    Indeed.
     

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