Will a surge protector work properly when it’s not grounded?

Discussion in 'Home Theater Projects' started by Matt_Smi, May 22, 2004.

  1. Matt_Smi

    Matt_Smi Second Unit

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    I was not sure where to post this but if there is a more appropriate place feel free to move it. Ok I need a definitive answer here, my room currently has no three prong grounded outlets in it, I plan to have them installed (hopefully I can without rewiring the whole floor). But for the time being can a surge protector still do its job properly and protect my equipment from a surge if it’s plugged into a two prong outlet with an adaptor or “cheater plug”? I have heard different things on this and I need a straight answer. I recently read this from the crutchfield site

    Q: I only have a 2-prong outlet — can I use a power protection model with a 3-prong plug?

    A: A power protection unit can be used with a 2-prong adapter to prevent surge and spike damage. However, doing so will invalidate the power protection unit's connected equipment insurance policy. A 3-prong outlet should be used whenever possible.
    "

    But I have also heard before that a surge protector needs to be grounded to work and if it’s not than it’s useless. The main reason I ask is because right now I am using cheap $10 surge protectors for my A/V setup and my computer, I want to buy some decent ones, but I don’t know if I should even bother getting them now, or if should wait until I hopefully get my outlets grounded, if they don’t work on an un-grounded outlet than there is no sense in buying new ones yet. Also should I bother paying extra for a surge protector like the Monster one in the link below, or should I save my money and just buy a “no name” one like the cyber power in the other link below. Thanks to anyone who can clear this up for me, because I have been wondering about it for some time now.


    Monster Surge Protector
    http://www.monstercable.com/power/pr...er.asp?pin=592

    Cyber Power Surge Protector
    http://www.circuitcity.com/detail.js...&oid=70965&m=0
     
  2. Chu Gai

    Chu Gai Lead Actor

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    Your assesment is correct. A surge protector works by diverting a surge to ground. The joules rating that you see is indicative of the life of the MOV's that are typically used in them. The bigger the number the greater the lifetime.

    I don't know what Crutchfield is getting at here but it may be a very liberal interpretation of the word surge. I think it's bad advice.

    You've got a couple of options here apart from running wire.
    If you have your own home you can look into installing a whole house protector. This sits at either the mains or the meter. This would provide bona fide surge protection for your entire home and quite a bit more effective than a point-of-use system. Search under my name and those terms for more information. They can be installed by the enterprising home owner, an electrican, or may be provided by your local utility company for a small surcharge per month.
    Some homes without the ground wire, as yours is, may be wired with BX or armored cable. This will have a metal casing around the wires. If this is what you have and it goes from the metal box where your outlet is all the way to where your breakers or fuses are located, then you're in luck because the outer casing of the BX will act as ground. Your entrance box, where the fuses or breakers are located, must be connected to ground. Check to make sure that's the case. You can test by using a multimeter and attaching one lead to the hot wire and the other to the metal box that your present outlet is in. The voltage ought to be 120V, give or take. If all is go so far, you'll kill the power to your outlet. You'll then replace the 2-prong outlet with a 3 prong outlet. The 3-prong outlet will have a green ground screw which you will attach to a screw into the metal receptacle box. Home Depot or Lowes ought to help you out with that.
    Make sense?
     
  3. Neil Joseph

    Neil Joseph Lead Actor

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    Real Name:
    Neil Joseph
    Moved to Accessories.
     
  4. Matt_Smi

    Matt_Smi Second Unit

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    Ok so a surge protector does have to be grounded to work! I have no idea why crutchfiled would list something like that when it’s false. I am 19 and live with my parents, I don’t really know how much a whole house protector would cost but I am assuming it’s not an option for me and would be an overkill since I am the only one in the house who really cares about surge protection anyway. Other rooms in my house have grounded outlets, the kitchen (which is below me does) but I think that it was rewired at some point in time, the upstairs bathroom near me and my brother’s room (on the second floor near mine) has one grounded outlet in it. My house is not too old, and I think it was built in the 50’s. Anyway I think I have romex wiring, not BX as the wiring in my house does not have any metal casing around it. I believe that some of my house was re-wired at some point (the kitchen mainly), but my room still has original wiring the think. I honestly think that I am pretty much screwed, and that all the wiring to the outlets in my room would need to be replaced in order for my outlets to be grounded. I have no idea how much this would cost but I bet I or my parents would not be willing to pay for it. It really sucks though, as I cannot have my gear protected from surges, and it’s dangerous! Thanks for the help and info!
     
  5. Bill Kane

    Bill Kane Screenwriter

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    Matt,

    hold on, all is not lost.

    It's quite likely the outlets in your room ARE grounded, even tho you see two-prong outlets.

    First, to verify, you will need some type of hand-held outlet checker that provides an indicator light (LED) for GROUND. Hardware stores sell these for under $10. You can check ALL the outlets at home, and if you find something wrong like crossed wires, you can be a hero, tho it may cost your 'rents some dough for an electrician.)

    In fact, most all surge protector strips carry this light, if you can borrow one to take home and plug in. Of course this may take a cheater plug, if there is a "prong".

    Since we want to avoid cheater plugs in the end, it't no problem to install a three-prong outlet; I've done many.

    Assuming your existing outlet IS grounded, as Chu says there should be a green wire inside. The outer end of this GRD wire attaches to the green screw on your new 3-prong outlet. (If you do buy one, spend a little more for a COMMERCIAL or INDUSTRIAL SPECIFICATION. They have thicker and tighter brass plates (blade holders). Look on the box for this spec.

    bill
     
  6. Kevin. W

    Kevin. W Screenwriter

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    Matt another option is to replace your receptical with a GFI type. These have built in sensors that trip the circuit in the receptical if somethings wrong.

    [​IMG]

    Kevin
     
  7. Matt_Smi

    Matt_Smi Second Unit

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  8. Matt_Smi

    Matt_Smi Second Unit

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    Ok I just picked up a $5 circuit analyzer that tells if your outlets are wired correctly and if they are grounded or not. I plugged in into an adaptor and then into one of my outlets, here is what happened, plugging it into my outlet obviously resulted in the “open ground” lights, but if I touched the grounding screw of the adaptor to the screw on my outlet the lights that indicate the outlet is correct lit up. Does this mean I may be able to install grounded outlets without a big hassle? Or does the tester simply see anything that is metal (in this case the outlet screw) as a ground? I don’t really know what this may mean, but maybe there is hope!


    EDIT: It does not see just any metal as a ground, as I tried touching some different metels to the grounding screw and it did not light up as being correct. I think that this is a good sign, hopefully someone with knowledge can tell me just what this means. I wonder if for now I could just attach the screw of the outlet to the grounding screw on the adaptor and be ok?
     
  9. Bill Kane

    Bill Kane Screenwriter

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    Matt,

    It's somewhat dangerous for two unlicensed tinkerers to talk ELECTRICITY via etherwaves, but here's what I suggest.

    The goal is NOT to use a flimsy cheater plug adapter, tho it may ground via that connection to the outlet screw.

    First, you must feel comfortable in exploring your circuit box(es).

    Go to go to your Main Electrical Panel and throw the breaker switch (pull the fuse?) for the outlet in your room. I use an ext. cord with a light bulb at the end to verify the outlet goes dead.

    Secondly, you then can remove the wall plate, unscrew (two of em top and bottom) to GENTLY pull out the existing duplex. Typically there will be a black (hot) wire attached to a brass screw, plus a white lead to a nickel-colored screw. {Some duplex installations used a push-in style with the lead, no screw down. If you find this, it will complicate using a new duplex, but it can be done).

    Check to see if there is a third 3-inch wire, perhaps green, attached to a screw in the rear of a metal box. Leave this in place but remove it from the old duplex.
    ASSUMING YOU FIND THIS GRD WIRE...since you report a tenuous ground with the adapter I am making a leap of faith that this grd wire is present and you have a metal junction box that is attached to metal conduit back to mains panel(???).
    I wud buy a COMM'L SPEC duplex and replace the old one. follow the color-screw codes above. Wrap the wire CLOCKWISE around screws so when it's tightened down the wire clamps inward. A green terminal screw is for a grd wire. Needle-nose pliers do the trick.

    Before pushing the new duplex and wiring back, briefly energize the circuit to see if it works properly with light or radio. Also, you can use your new circuit tester to verify GROUND OK.

    What do you think?
     
  10. Matt_Smi

    Matt_Smi Second Unit

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    Sounds good, thanks for your help! Now what if there is no ground wire in there, does that mean the box itself is grounded?
     
  11. Bill Kane

    Bill Kane Screenwriter

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    One step at a time...like a car mechanic, you gotta open it up and see what ya got. There are several variables here.

    Look at it this way: The actual GRD exists in the earth outside the Mains Panel, usually a 4-ft stake with a thick wire running to the manis panel. Modern 12-AWG/2 or "Romex" provides a 3rd or copper wire in the flex to make the electrical ground at the duplex end.

    Up until the 1950s or so, the ground existed by using a metal junction box with metal conduit that made a physical connection at the fuse box, and thence to actual earth ground.

    Your house may have been fixed/half fixed/left dangling... who knows until you see and can describe what's in there.

    bill
     
  12. Matt_Smi

    Matt_Smi Second Unit

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    Hey Bill, I took off the outlet plate and without pulling the outlet itself out I can see an extra copper wire in there that is not hooked up to anything, is this my ground wire?
     
  13. Chu Gai

    Chu Gai Lead Actor

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    More likely than not. Now test the voltage from the hot to that ground wire. If you get a reading then just get a regular outlet at home depot (spring for the industrial grade, they're a little beefier) and rewire. Don't forget to turn off the breakers to your room for safety.
     

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