Ungrounded Outlets and 3-pronged Cord

Discussion in 'Amp Tech Center' started by 50ShadesofOrange, Jan 19, 2020.

  1. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    I’ve picked up a stock 1973 Vibro Champ, and I’ve got someone going over it to check its function/safety.

    I’m in an older home, and I’m pretty certain none of my outlets are grounded.

    From what I’ve researched, the death cap has gotta go, but based on the lack of grounded outlets in my house, am I gaining anything by replacing the original cord with a 3-pronged one?
     
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  2. schmee

    schmee Poster Extraordinaire Silver Supporter

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    Well, not in your house anyway!
     
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  3. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    Thanks.

    That’s kind of what I suspected.
     
  4. rolandson

    rolandson Tele-Holic Silver Supporter

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    Uh....yeah, your life.

    Get one of these...
    [​IMG]

    See that little green lug...
    Screw the outlet plate screw through it. Your j-box is metal. It's grounded. Now your amp will be too.

    ETA:
    the j-box is the enclosure that is "inside" the wall, in which the outlet is inside of. In the old days, the days of two pole outlets, the outlet and the box were grounded...the third prong...

    all electricity is seeking ground. The bridge and therefore the strings of your guitar are grounded.

    Should something go wrong in your amp, without the ground provided by the little green lug being properly screwed into your outlet, that electricity will use the next best thing for ground...

    You.
     
    Last edited: Jan 19, 2020
  5. The Ballzz

    The Ballzz Tele-Afflicted

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    Well Yes! You gain the incentive to have at least some of your circuits upgraded to being safely/properly grounded, :rolleyes: although one might think that the desire to stay alive would be incentive enough! :p Of course, we rarely hear from folks who have had first hand experience with improperly grounded wiring, likely because they are DEAD!

    Make no mistake here: DEATH IS A PERMANENT CONDITION! :eek:

    Just My $.02 & Likely Worth Even Less!
    Gene
     
  6. The Ballzz

    The Ballzz Tele-Afflicted

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    While your first sentence is right on the money, without testing, we're not certain of the box being metal and/or that it is grounded!

    Just Sayin'
    Gene
     
  7. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    Thanks, Rolandson.

    I’ve tried those adapters, but I’m not sure the outlets are wired correctly for the plate screws to ground the adapter.

    I’ve used those, and when testing for a functioning ground, no dice.

    It might be time to bite the bullet and look at upgrading a few outlets around the house.
     
  8. rolandson

    rolandson Tele-Holic Silver Supporter

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    Then I would say an electrician is in order.
     
  9. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    It would appear so.

    Now I just need to explain to my wife that this was unsafe *before* I bought the amp.

    Would GFCI add the safety without opening my wallet for an electrician?
     
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  10. scooteraz

    scooteraz Tele-Afflicted

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    Uhhh, no. Now you need to explain to your wife why she was safe in the kitchen before the update, but you’re not safe now....LOL

    Maybe you could could upgrade the kitchen sockets first saying, “Gee honey, I just discovered this issue.”
     
  11. alnico357

    alnico357 Tele-Holic

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    That little adapter makes a great ground lift when needed.
     
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  12. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    Thank you all for your help.
     
  13. warrent

    warrent Friend of Leo's

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    Can I make ungrounded circuits safer?

    I’m remodeling an early 1960s house. None of the old wiring has a ground wire, and all the plugs are two-prong. The new circuits in the remodeled areas are grounded, but rewiring the old outlets is pretty complicated due to the interior finishes and limited access to the attic and basement. Is there any way to ground the old circuits?

    Mike Guertin, East Greenwich, RI

    A:
    Marc Massa, master electrician and owner of Stony Lane Electric in Exeter, Rhode Island, replies: Rewiring could get expensive and messy fast because you have to cut holes in the finished walls to snake new wires. You can, however, get groundfault protection by installing a GFCI (ground-fault circuit interrupter) device to protect each circuit. This will allow you to install grounded outlets downstream of the GFCI device, eliminating the need for your client to use adapters.

    There are two ways to do this. You can replace the first outlet in a circuit with a GFCI outlet, or you can replace the circuit breaker at the service panel with a GFCI breaker. Replacing the outlet is the most cost-effective solution because GFCIs cost only about $12; GFCI breakers are closer to $30.

    Locating the first outlet can be tricky. It’s likely that the circuit feeds are routed through light fixtures before branching to outlets, which was common when the house was built, so replacing the breakers will be simpler. Still, I prefer to replace the outlet rather than the breaker because GFCI breakers tend to be more sensitive than GFCI outlets. Clients don’t mind resetting an outlet in the next room but will be cursing you every time they have to run to the panel in the basement to reset the breaker (even though it just may have saved a life).

    The NEC 2005 allows this alteration to existing electrical systems [406.3(d)(3)(c)] but requires that each two-prong outlet that has been changed out to a grounded outlet be labeled as “GFI protected. No equipment ground.” I print up stickers on my label maker to mark outlets neatly.

    This technique works because of the way GFCIs function. In the event that the GFCI senses a current difference between the hot and neutral conductors passing through it, the GFCI will open the circuit and stop the flow of power.

    The difference occurs when current leaks to ground, as in the case where you reach for the kitchen faucet while popping bread into a toaster. As soon as the slightest current flows through your body from the toaster to the faucet (grounded by virtue of its connection to copper water pipes), the GFCI will pop because it notices that the hot wire is carrying more current than is returning through the neutral wire connected to the device.

    Although the technique of installing GFCI devices in an ungrounded circuit doesn’t ground the circuit, it does provide protection in the event that any electricity leaks to ground, thereby preventing electrical shocks and injury.

    https://www.finehomebuilding.com/2006/03/01/can-i-make-ungrounded-circuits-safer

    hb177QA01-01_lg.jpg
     
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  14. Ricky D.

    Ricky D. Doctor of Teleocity

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    This is not electrician brain surgery, quick and easy for a guy that knows how. Blow a hundred bucks and safe those outlets.
     
  15. guitarsophist

    guitarsophist Tele-Meister Silver Supporter

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    Get a cheap little tester that will test the ground situation. You used to be able to get them at Radio Shack, but you can get them on Amazon. You just plug it into the outlet and some LEDs light up. Depending on what lights up, you can tell if it is grounded properly, or perhaps even more important, whether the polarity is correct. I used to practice at a guys house where one of his circuits was wired backwards. If the guitar amp is plugged into a circuit wired correctly, but the PA is plugged into one that isn't, you can get a bad shock from touching the mic. I kept getting a shock, but fortunately, I was just lightly touching the mic, not grabbing onto it. He didn't quite believe that there was a problem, so I brought a tester and he was convinced. He had to have an electrician rewire that outlet.

    I believe Keith Relf of the Yardbirds died from this kind of bad wiring.
     
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  16. King Fan

    King Fan Friend of Leo's

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    @warrent nailed this... Misinformation is dangerous here, and all too common. The idea the wall box is metal and grounded? -- in an older home, yes, it's more likely you have a metal box, but way less likely it's grounded. Zap.

    GFCI on the *first outlet* is excellent for safety. (If you want to totally protect your gear, a true ground wire back to a tested building ground is conceivably better. But potentially destructive of walls / floors / etc. and very expensive).

    Finding the *first* outlet and tracing the circuit can be tricky. I'd consult an electrician, asking him to put GFCI outlets in bathrooms and kitchens (so family are safe) and on the first outlet in your amp-outlet circuit. That limited work may be $1000s less costly than running actual ground wires.
     
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  17. 50ShadesofOrange

    50ShadesofOrange TDPRI Member

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    Thankfully we already have GFCI outlets in the bathrooms and kitchen.

    And digging around some more, I took a chance and tested the outlets the cable company and alarm company used for installing equipment. Lo and behold, they grounded them, no doubt to protect their equipment.

    Whatever the case, I’ll take the win.

    That said, tomorrow I’ll be calling the guy checking out the amp and let him know I’d like to go ahead and swap the cord to a 3-pronged one.

    Thank you all again for your help!
     
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  18. JL_LI

    JL_LI Friend of Leo's

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    My house is more than a hundred years old. It was built as a farm house by an immigrant from eastern Europe. I don't know if his wiring skills were questionable, or if owners between when he sold it and I bought it didn't know much. It may have been that there were no building inspectors in 1909. My house didn't show up on the tax rolls until 1938 and building plans were never filed. Polarity is a real issue with modern electrical appliances. It doesn't matter which way current flows through an incandescent light bulb but it matters with anything with a motor or with almost anything with a printed circuit board. When I moved in, most of the outlets were not polarized, and of those that were, many were wired in reverse. Most of the wiring was cloth covered and black from age so it was impossible to tell visually which wire was hot. A contractor found that the house ground from the electrical box had become disconnected from the grounding spike outside the house. I changed outlets when I moved in but I had no idea that the house ground was disconnected. That wasn't discovered until a licensed electrician upgraded the us from a fuse box to a breaker box. I would encourage anyone moving into an older house, to me, one constructed before 1975, to have the wiring checked by a licensed electrician. My house still has never been inspected. I've gotten building permits for all major work done, but the town only seems to care about the permits so it can raise my taxes.
     
    Last edited: Jan 19, 2020
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  19. nojazzhere

    nojazzhere Doctor of Teleocity

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    You're getting a lot of advice and suggestions here, most of which are great GIVEN CERTAIN UNKNOWN CONDITIONS......meaning, your outlet box MAY OR MAY NOT be grounded. Some older homes with two-prong outlets have wire run in metal sheathing that is grounded from the breaker box to the outlet, in which case you're probably OK....but without testing, you have no way of knowing. You may have old knob and tube wiring in your hose, which is not even safe running a coffee maker. Sometimes previous homeowners "up-size" fuses or breakers without upgrading the wiring itself. As much as I respect the folks here, and I know they would NEVER intentionally tell you wrong, I STRONGLY urge you to spend a few dollars and get your house checked by a certified expert.......that is, unless you don't care for your and your family's safety. ;)
    EDIT.....JL_LI's post slipped in while I was typing, and his is right on! You can never know what was done in the past, but your life may depend on it......
     
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  20. stormsedge

    stormsedge Tele-Holic Gold Supporter

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    We had a 1920s house (~1700sq) completely rewired...took the guesswork out of it. I wasn't there to see how they pulled the wire, but it was nice when complete. Added a couple of outlets where we knew our computers and entertainment stuff would be, and put outlets on the outside of the house for lawn/garden gear. That particular house still had knob/tube in it, so no real choice if we wanted it insured. Cost ~$7k in 2010.
     
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