To plug or not to plug into a GFCI outlet

Discussion in 'Electrical Forum discussion & Blog' started by DIY, Apr 6, 2009.

  1. DIY

    DIY New Member

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    GFCI outlets are located throughout this house,other than the bathroom and kitchen.Is a PC, or stereo etc. protected if plugged into a GFCI outlet with or without a surge suppressor?
  2. Gary Swart

    Gary Swart In the Trades

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    GCFI is not a surge protector for computers if that is your question.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    A gfci is designed to prevent you from getting electrocuted if there's a fault in the wiring or device plugged into it. It measures the current on the power lead and compares it to the neutral...if they aren't the same, some leaked to a new ground, which might be you, then it shuts the power off.
  4. DIY

    DIY New Member

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    GFCI plug in or not/question rephrase

    Is it a good idea to plug a PC,laptop,stereo etc. into a GFCI outlet?

    Just as i have learned a refrigerator should not get a gfci outlet due to the potential food spoilage it can cause.Might it do similar with regards to a data loss/memory loss etc. with a PC/laptop?
  5. cwhyu2

    cwhyu2 Consultant

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    It is not a good idea to plug a P/C into a GFCI,for the reasons you stated.
    If you do a battery backup system would help,it would also help in a
    power outage.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    A properly operating electrical device should work in a gfci protected circuit...including a refrigerator. If it trips it, it has a problem and could kill you which is worse than losing some food from spoilage or having your computer shut off. Get the appliance fixed, verify the gfci is working properly, or replace them as required.
  7. jwelectric

    jwelectric Electrical Contractor/Instructor

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    The statement in bold above is nothing but hog wash and anyone who makes this statement doesn't have a clue about electrical current and needs some formal training.

    Any thing that uses electrical currnet can be plugged into a GFCI without concern of loss of anything.

    The statement in bold above is saying that in the event of a power failure all your food spoil. Just like with a power failure you know that the refrigerator isn't working and take measures to stop from losing the food unless someone is just to stupid to know that the refrigerator isn't working.
    Last edited: Apr 7, 2009
  8. Bill Arden

    Bill Arden Computer Programmer

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    The problem with GFCI's and surge suppressors is that power spikes can cause them to send current threw the ground conductor and that will trip a GFI.

    Some of the fancier refrigerators have electronic controls and surge suppressors.

    Also as a surge suppressor ages due to repeated "hits" it starts to leak more and more current and that will also trip the GFCI.

    The best option for a PC is to add a surge suppressor and a Good UPS. Don't bother with the really cheep ones since they burn out the lead acid battery's every year or two due to overcharging.
  9. DIY

    DIY New Member

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    gfci plug into

    I appreciate your reply rock of marne. Actually your one sentence answers two of my questions about gfci outlets...... I will consult a professional electrical contractor locally regarding other questions and if gfci outlets are the best option to be installed here.
  10. jwelectric

    jwelectric Electrical Contractor/Instructor

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    You might would want to contact UL at UL.com and ask them the same question you have posted here as well as asking about any appliance including a refrigerator being plugged into a GFCI.

    They are the ones that puts their labels on these appliances and if there is anyone who can give you a straight answer I would think they would be the one.

    Yes I have talked with people from UL and already know the answer you will recieve but do it yourself and then all questions will be put to rest in your mind.
  11. Bill Arden

    Bill Arden Computer Programmer

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    I've gone threw the UL process and they don't care if the device functions. All they care about is if it is safe.

    I've also had UL approved devices short out, and do other bad things.

    Back to the original question. You want to add a surge protector to a PC, stereo, etc. If the GFCI trips then try a different surge suppressor.
  12. jwelectric

    jwelectric Electrical Contractor/Instructor

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    All GFCI devices have to be built to meet UL Standard UL 943 and gapped silicon-carbide surge arresters for ac power circuits are required to meet Standard IEEE C62.1 with metal-oxide surge arresters for ac power circuits, the most common, meeting Standard IEEE C62.1.

    Each of these standards is the guide lines that each piece of equipment must meet in order to be listed. Each of these standards mandates that the each device functions in a safe manner and also mandates the amount of voltage and current each device is to detect.

    In the case of a GFCI device it is to open when there is more than five milliamps of current difference in the current carrying conductors. At five milliamps, according to OSHA, slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary reactions to shocks in this range may lead to injuries.

    If there is an appliance be it a power tool such as a drill or even a refrigerator or freezer that trips out a GFCI device then it is time to get rid of that appliance and replace it with another.

    Surge arrestors on the other hand have a component that is called a clamping device which reads the peak voltage and clamps a sine wave that reaches a set point, on a 120 volt device this will be around 330 volts to peak, letting the upper range of the voltage go to ground. Here we are not talking about any current emptying out into the yard (ground) simply because the physics of current flow states that every one of them electrons that leave a supply must return to that supply.
    The word “ground” as used here is implying the same word that Article 200 of the NEC is addressing or what we have come to call the neutral in the field. The neutral is required to be connected to earth at every service therefore called the grounded conductor.

    All this clamping device does is cause a short circuit from hot to neutral letting any high voltage bypass the load connected to it. This short usually happens to quick to open any overcurrent device such as breakers or fuses.
    If this voltage is going back to the neutral then the current will always be the same and the GFCI will not trip.

    In the event of a lightning strike where the current is trying to go to earth then the tripping of a GFCI device only goes to aid the surge arrestor in protecting the equipment and the result of a tripped device is good and not bad.

    Once again all this hog wash being passed around about this or that tripping a GFCI and that is bad is nothing more than hog wash and holds absolutely no merit.
    Last edited: Apr 8, 2009
  13. jwelectric

    jwelectric Electrical Contractor/Instructor

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    The author of an email I received asked if the voltage that was choked by an arrestor not allowed on the equipment grounding conductor.

    The confusion comes from the term “ground†with statements like, “the spike is shorted to ground.â€

    The neutral conductor of a service is a current carrying conductor that is required to be connected to earth therefore the neutral has one Article of the NEC devoted to just that conductor, ARTICLE 200 Use and Identification of Grounded Conductors.
    The neutral is called the grounded conductor in Article 200 of the NEC hence the term “leakage to ground†is born and erroneously thought of as letting current flow into earth.

    In an AC circuit the voltage is the amount of push or pressure the current (amperage) is getting to push through a resistance or load if you please. The more voltage the quicker the current can be pushed through or the more resistance that can be over come.
    Should the push or voltage become strong enough it could push the current through the insulation that surrounds the conductor.

    On a hydraulic system a pressure control valve will let excess pressure bypass the system and bleed back into the reservoir tank. It doesn’t let the fluid squirt out all over the place and make a mess like some seem to think electrical current is allowed to do.

    The surge arrestor just like the pressure control valve of a hydraulic system, lets this extra pressure or voltage bleed back to the reservoir tank, its source and does not squirt it out into the earth. This is achieved by shorting to the grounded neutral conductor, a conductor installed to carry current, so the term bleed to ground is born.

    The equipment grounding conductor is installed for the purpose of establishing a low impedance path to the source in the event current gets on the non-current carrying metal of the electrical system or equipment connected to this system. It is not installed to carry current except in the event of a fault. If there is a voltage on the equipment grounding conductor something is wrong with the system.

    To allow the top of a sine wave be shorted to these non-current carrying metal parts of the electrical system would let the voltage potential of this metal rise and fall in sequence with the surges.
    I don’t see how letting this potential be directly connected to the metal of a system could ensure that the system would be stable under normal operation one of the purposes of connecting a system to earth as outlined in 250.4(A)(1) nor how this could possibly keep objectionable current off these items as outlined in 250.6.

    No the choke does not connect to the equipment grounding conductor. For whole house surge arrestors there will be three conductors, two ungrounded and one white grounded conductor. Nothing in this unit connects to the equipment grounding terminal of the panel just as nothing connects to the equipment grounding conductors in those remote 120 volt units. Everything is grounded to the grounded (neutral) of the device.
  14. Bill Arden

    Bill Arden Computer Programmer

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    I have UL approved power strips with "full protection"(marketing term) surge protection that has 3 MOV's that connect between all three conductors. They also make power strips with three filter capacitors.

    These kind of surge suppressors are needed since lighting can damage equipment if the neutral to case/ground voltage gets too high.

    I can take photo's if needed...
    PS: this is also the power strip that shorted out when I plugged a plug into the end socket due to a small piece of internal plastic snapping off.

    - Reference
    Woods "full Protection" surge suppressor
    Model PT-F04
    UL E115193
    Listed 50EB
    I believe that I bought it in 2004.

    Of course this debate is now pointless since both sides say you should use surge suppressors on computers and stereo's even if you have GFCI's
  15. jwelectric

    jwelectric Electrical Contractor/Instructor

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    I have 67 duplex receptacles in my house and every one of them has all three wires connected to them. I can take pictures if you like.

    Does this mean that the equipment grounding conductor is carrying current?

    Edited to ask;

    Does the fact that the MOV has the equipment grounding conductor connected to it mean that it wouldn’t work on a two wire device?

    If it will work on a two wire device then I would say that the fact that the equipment grounding conductor is connected to it wouldn’t mean a lot wouldn’t you?
    Last edited: Apr 11, 2009
  16. DIY

    DIY New Member

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    Location:
    Florida
    gfci stuff

    I did not mean to start a debate about this gfci thing. The answer to my question was answered in one of the first 3 or 4 replys,but do not get me wrong i appreciate all efforts that went into replys. Now onto what i saw a few days ago. In the house i was invited to i noticed every single outlet throughout had gfci outlets..? Why? I asked the owners out of curiosity and they told me because the way the house was originally wired. All outlets boxes had only two wires running into them,so in turn they did not have a way to protect other outlets down a circuit. Interesting. Thought i'd share that bit of info. with this forum. Happy weekend to all.
  17. Thatguy

    Thatguy Homeowner

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    http://www.google.com/search?client=safari&rls=en-us&q="nuisance trip" gfci&ie=UTF-8&oe=UTF-8

    Capacitance from motor windings to the motor shell of more than 0.09 uF will also trip these things, in addition to internal RF filters to protect electronic circuitry.

    With all the discussion about GFCIs and AFCIs, I hope these things actually save some lives, compared to not having them. I couldn't find any before and after data on this.
    With driving in a car being 30x more dangerous than electricity on a per year basis, does the NEC/UL and various elec. manuf. have this?
    http://en.wikipedia.org/wiki/Zero-risk_bias

    And watch out for
    http://www.google.com/search?client=safari&rls=en-us&q=define: astroturfing&ie=UTF-8&oe=UTF-8
    as far as how reliable or not these things are.
    Last edited: Apr 11, 2009
  18. jwelectric

    jwelectric Electrical Contractor/Instructor

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    This is totally untrue. Unless my math and memory has completely failed me I think that we can mathematically disprove this statement.
    The capacitive reactance of .09 microfarad would be the reciprocal of two times pi times the hertz times .09 divided into one million or somewhere around twenty nine thousand four hundred seventy three ohms. Now divide this into 120 volts and we have 4 milliamps and just under the allowable trip limit.
    Of course capacitive leak has not been allowed to be this high for well over 20 years now so although the statement holds some merit it is long outdated. Sort of reminds me of the old vacuum tubes from days gone by.

    RF filters on the secondary side of equipment power supplies we won’t even discuss as they don’t come close to fitting into this discussion.

    What the National Fire Protection Association and all National Testing Laboratories do have is a bad case of trying to protect the general public from the dangers arising from the use of electrical energy.
    Not many people call up and say that this GFCI device saved my life today so a different approach is taken. A count on how many people was hurt due to electrical shock and then after the codes mandates a protective device the total number of accidents should be lower if the device has any merit.
    Your comment about driving I think would be like comparing grapes to grapefruits. Take a look at the numbers when electricity was first introduced to the public. One could easily ascertain that electricity was a lot more dangerous than driving a car. It is through the continuing changing of the codes that keeps electrical energy at bay and the number of accidents and death as low as possible.

    I agree and think that everyone should have a full understanding of electrical current flow if they are going to be messing around with it, wouldn’t you? All need to be assured that the advice you are receiving holds merit and not just someone copying and pasting from another discussion board.
  19. Thatguy

    Thatguy Homeowner

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    Nowadays the danger from elec. is down in the noise, probably for many reasons.
    1300/yr electrocuted vs. 40,000 highway deaths/yr vs. 1000/day smoking related fatalities.
    I'd look at what add'tl increment in safety you get for each dollar spent. If you say a CB gives you $20 worth of safety then an AFCI maybe gives you $1 more worth of safety. It's the law of diminishing returns.

    Do these quasi-governmental agencies mentioned above fit this description?
    "Regulatory capture is a term used to refer to situations in which a government regulatory agency created to act in the public interest instead acts in favor of the commercial or special interests that dominate in the industry or sector it is charged with regulating."

    "Public choice theory holds that capture is inevitable, because vested interests have a concentrated financial stake in the outcomes of political decisions, thus ensuring that they will find means—direct or indirect—to capture decision makers"
    Last edited: Apr 12, 2009
  20. jwelectric

    jwelectric Electrical Contractor/Instructor

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    None. With today’s technology little to no current is lost through capacitive induction in the motor frame. The use of ceramic dipped windings was discontinued way back in the 60s and somewhere in the mid to late 80s it was mandated that the leakage of motors to be addressed to very low levels. I am not sure of the numbers but can find out if it would make you happy.

    You are not looking in the right places or simply disregarding the information you are finding. The numbers are simple to find if you truly want to find them. Start with looking at the numbers that Fire Marshals have. These can be found at both state and federal levels.

    In the first couple of months after the bid was released to Westinghouse for the world’s fair there was 600 deaths in the state of New York alone, but less than 10 across the nation due to automobiles for the entire year. (reference source National Fire Protection Association)

    Spoken like a true, protect me from the thieves, murders, and rapist but don’t dare try to tell me what to do, type of cult.

    To disprove another’s thought we can use abstract comparisons to show just how low the numbers truly are. I think that you comparison is sort of like comparing the number of stars to the number of candles in a Catholic church on any given day. We must admit that the candles will light the church at night better than the stars so which is more dangerous? Can one blow out a star as easily as one can blow out a candle?

    To bring this outrageous comparison a little closer tell me just how many people are in a moving car and for how long each day. How many people light a cigarette and how many times a day? How many are coming in contact with a live electrical circuit each day? How many electrical fires are there each day?

    Now if we had as many people working with live circuits or on unprotected circuits each and every day as we have in automobiles and lighting a smoke I can guarantee that the numbers would look a lot different wouldn’t you think?
    Thank God that there is a power higher than our self to mandate some sort of safety. Can you imagine the chaos we would have on our streets if there were no highway patrol to enforce the laws or even worse if there were no traffic law set in place at all?
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