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UPS with 2 prong, un-grounded outlet / Use of adapters and GFCI | Back-UPS & Surge Protectors

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UPS with 2 prong, un-grounded outlet / Use of adapters and GFCI

Discussion in Back-UPS & Surge Protectors started by Slack , 8/14/2019 5:21 PM
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UPS with 2 prong, un-grounded outlet / Use of adapters and GFCI

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  • Slack5537

    I'm in a house that has grounded outlets in the basement, but on the second floor, this one I need to plug into, it is not grounded.

    1.) It's a two-prong outlet
    2.) The slits are large and small (neutral and hot) - not the same size, which is good / more modern

    1.) I have a multi-meter
    2.) With the red lead in hot, I touched the screw of the faceplate, and get nothing, so that shows that it's not grounded

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    I currently have two . . . APC Back-UPS 425 (BE425M)'s . . . plugged into this outlet, using this adapter:

    15 Amp 125-Volt 3 Outlet Grounding Adapter with Grounding Lug . . . https://www.homedepot.com/p/Eaton-15-Amp-125-Volt-3-Outlet-Grounding-Adapter-with-Grounding-Lug-BP1219V/206469379

    I was going to attach the adapter to the outlet, with the Grounding Lug on the adapter and face plate screw, but the holes didn't line up.

    The UPS's have red lights on, on them, which indicate "Not Grounded"

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    I read that I can put in a GFCI outlet, and that would be good, because the surge side of the UPS shunts to ground . . . If there is no ground, it can go to your equipment

    But, this outlet box is probably too small for an "in-the-outlet-box" type of GFCI . . . which leads me to some questions:

    I was thinking of getting one of these:

    TRC 90033 Shockshield White Portable GFCI Plug with Surge Protection . . . https://www.walmart.com/ip/TRC-90033-Shockshield-White-Portable-GFCI-Plug-with-Surge-Protection/47488951

    It looks like it's a 3-prong, based on the video here, that would make sense:

    TRC 14650006-6 Shockshield White GFCI Plug with Surge Protection . . . https://amzn.com/B000XVG72G

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    Then I plug in:
    1.) the 3 Outlet Grounding Adapter into the wall - or a single - maybe I can find one where the grounding lug lines up with the face plate hole, and that would secure it
    2.) the Shockshield into the Adapter (a 3 or 1 outlet)
    3.) the 3 Outlet Grounding Adapter into the Shockshield
    4.) the 2 UPS's into the 3 Outlet Grounding Adapter

    So then if there's a surge (but I think these are RARE occurrences), then the UPS's will trip the GFCI

    1.) The surge side shunts to ground - What about the battery backup side?
    2.) Would a brownout trip the GFCI? Creating something else to be aware of?

    Going through the adapter probably invalidates any warranty coverage . . . But that doesn't matter - protection from brownouts is all I'm interested in . . . I'm just wondering if having the GFCI protection is a good idea, or not.

    I don't know details about electricity like this . . . I think I probably have it the best way, as it is.

    Thank you for your help!

  • UnexpectedBill

    The GFCI won't do what you're expecting.

    The only proper solution would be the installation of a grounding conductor and the proper type of outlets.

    A GFCI doesn't magically give you a connection to ground where none existed. A GFCI looks for an imbalance in the electrical currents that are flowing from hot to neutral. If everything that is going out isn't coming back, the GFCI assumes that something bad is happening (some electricity leaving the GFCI is flowing elsewhere, perhaps through someone who would otherwise be experiencing a nasty electrical shock) and it cuts off the power. This could be anything -- a hair dryer that was dropped in the bathtub, a metal-cased power tool where a hot wire is touching the tool casing unbeknownst to the person operating it, etc.

    This is why it's possible* to replace an older two pin outlet with a three pin GFCI and still be able to enjoy the added safety. There's no safety ground, but the GFCI is still very much capable of sensing an imbalance between what's leaving on the hot conductor and heading back on the neutral.

    Neither a brownout nor a momentary imbalance in the currents flowing through a GFCI should trip it. It is difficult to say that with 100% certainty, however. Just like everything else, there are varying tolerances and different designs. It's possible for nearby electrical storms to trip a GFCI, if the conditions are just right.

    Surges (or spikes) are not particularly uncommon. The power line can be a nasty place. Any time something like a motor or transformer is turned on or (particularly) off, there can be an enormous, but momentary, pulse of surge energy dumped into the waiting power lines. Most equipment is built with the understanding that this is a "fact of life" and additional outboard protection isn't required.

    The safest thing to do would be not to use the UPS at all until the wiring and outlets can be updated.

    I can't really recommend using the UPS without the safety ground present. Yes, people do it all the time, and barring the red warning lamp being on, it'll work. You'll even get some surge protection, as surge suppression components are also typically attached between the hot and neutral pathways inside the UPS itself. What you won't have is the safety afforded by the grounding connection, and that might be very important if an attached piece of equipment developed a short to what should be grounded surfaces. Without a safety ground being present, this is a serious accident just waiting to happen.

    Whatever you may end up doing, DO NOT be tempted to create a "false" ground. This can lead to an extremely dangerous situation, as much as if not more than the safety ground's being absent.

    * I'm not sure that this has ever been approved by any electrical code anywhere. Still, it can be done in a pinch and will provide some added safety.

  • Slack5537

    Hello. Thanks for the info!

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    . . . The GFCI won't do what you're expecting . . . A GFCI doesn't magically give you a connection to ground where none existed

    Yes - it's not a ground . . . it just protects from detected electrical imbalances

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    If there were some issue where you had a huge power surge, and really needed the outlet to be grounded, but it wasn't:

    a.) I think the circuit breaker would trip

    b.) The GFCI would not trip - it's purpose is only to detect electrical imbalances - it does not act as a circuit breaker

    c.) So where would the huge amount of electricity go? . . . Stopped at your ungrounded circuit breaker panel? Maybe some gets to the UPS? I think the danger is that something could catch on fire.

    Haven't circuit breaker panels always been grounded? Apparently not.

    Some pages I've read say that the metal sheathing of the wire, to a metal outlet box, grounds to the circuit breaker panel . . . but haven't read that you need to be aware that in houses with 2-prong outlet, your circuit breaker panel might not be grounded.

    I think they need to say that in a house with 2-prong outlets, with metal electrical boxes, grounded by the wires in metal sheathing, that it's better if a fire start there, then by the device you're using.

    . . . Or, if the metal sheathing of the wire grounds to the circuit breaker panel, wouldn't the extra electricity go to the neutral at the circuit breaker panel?  That was the idea, then reality showed otherwise?

    . . . This would be in contrast to how if your circuit breaker panel were grounded, then the electricity would go to a metal stake that you have pounded into the ground outside of your house.

    But, the 2-outlet I'm plugging into shows as not being grounded at all.

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    . . . no safety ground in a GFCI, but it's still capable of sensing what's heading back on the neutral . . . not sure that this has ever been approved by any electrical code anywhere

    Please see these temporary GFCI plugs they have for tools (link below). Those are UL or NEMA approved - but not by any electrical code?

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    . . . DO NOT be tempted to create a "false" ground

    Do you mean, by installing a 3-prong outlet, or GFCI, and not having a sticker on it that says "No equipment ground"?

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    I'M THINKING THAT: The TRC 90033 Shockshield (link above) will do the same thing, and be more visually appealing inside, than one of these temporary GFCI's that they have for use with power tools:

    14 results for Leviton GFCI Plugs . . . https://www.homedepot.com/b/Electrical-Extension-Cords-Surge-Protectors-Extension-Cords-GFCI-Plugs/Leviton/N-5yc1vZcgerZwc?Ns=P_REP_PRC_MODE%7C0

    Conclusion: So, the GFCI (external mount) will provide some added protection to a 2-prong outlet

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    I'VE SEEN MANY FORUMS, and these official looking web pages, that recommend replacing a 2-prong outlet with GFCI (that's why I was thinking, why wouldn't something like the TRC 90033 Shockshield work?)

    Four ways to Upgrade Two Prong Outlets . . . Rewire Your Outlets (expensive) . . . Ground Three Prong Outlets with the Metal Housing Box (like playing with fire) . . . Install a GFCI at the Outlet (it might not fit in the box) . . . Install a GFCI at the Circuit Breaker (for each desired circuit, probably the best option) . . . https://www.whiteselectrical.com/blog-post/whats-problem-two-prong-outlets/

    How to Ground an Electrical Outlet With No Grounding Wire | Hunker . . . Don't ground to the electrical box [WHAT IF YOU TEST IT WITH THE CIRCUIT TESTER? WHICH IS LESS DANGEROUS, GROUNDING TO THE BOX, ASSUMING THE BOX IS GROUND, OR DOING NOTHING? IF THERE'S THAT MUCH ENERGY, BETTER IT GO INTO THE WALL, THAN SET THE UPS ON FIRE - IF THE TESTER SHOWS 120V, IT SHOULD BE OK, ACCORDING TO THE OTHER PAGE]. Connecting the ground wire to a metal electrical box will energize the box in the event of a short circuit. The box could overheat and start a fire, or someone could get a shock from touching it . . . Don't rely on metal sheathing or an exposed ground wire. If your electrical cables have metal sheathing that runs all the way to the panel, the sheathing can serve as a ground path. Alternatively, you might consider connecting the ground terminal to a water pipe by means of an exposed ground wire. Two problems make the safety of these approaches questionable: . . . The connection is often unreliable . . . The sheathing or wire gets energized in the event of a short circuit, potentially overheating and causing a fire or giving someone a shock . . . https://www.hunker.com/13414348/how-to-ground-an-electrical-outlet-with-no-grounding-wire

    How To: Fix Ungrounded Outlets | The Craftsman Blog . . . Electricity is like water in that it always chooses the path of least resistance. Without a grounded outlet, that path is either through your appliance which will fry your TV, computer, microwave, etc. or in the worst case, through you! You may think that having a surge protector is enough, but surge protectors only work properly when attached to a grounded outlet . . . You can swap out your standard outlet for a GFCI outlet on any ungrounded outlets to provide protection from shocks and surges; however, you will need to add a sticker to the GFCI outlet that reads “No Equipment Ground” which comes with every GFCI outlet. This lets other folks understand what is happening behind the walls in the future . . . A GFCI will “sense” the difference in the amount of electricity flowing into the circuit to that flowing out, even in amounts of current as small as 4 or 5 milliamps. The GFCI reacts quickly (less than one-tenth of a second) to trip or shut off the circuit . . . https://thecraftsmanblog.com/how-to-fix-ungrounded-outlets/

    2 Prong Outlets Are Not up to Code | Mr. Electric . . . You may need to replace the outlet box to accommodate a larger GFCI receptacle [NOT EASY TO DO]. A GFCI installed in this way is not grounded, so while this option prevents shock-related issues associated with two prong outlets, it provides no ground protection for sensitive electronics . . . Retrofit a Three Prong Receptacle Without Rewiring - Metal boxes found in most old outlets are attached to an armored cable, which serve the same purpose as a ground wire. You can take advantage of this to ground the receptacle without rewiring. First, test for a grounded box with a circuit tester. Insert one prong into the shorter hot slot and touch the other prong to a cover plate screw. If the circuit tester lights up, the box is grounded. You now know an electrician can inexpensively ground the receptacle without rewiring it . . . https://mrelectric.com/blog/2-prong-outlets-not-up-to-code

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    It would be useful to me to see a page that explains the above . . . how you can use a couple UPS's on a 2-prong outlet, and a GFCI would give you some added protection, but the danger is that in a power surge, your circuit breaker panel, or UPS, could catch on fire . . .

    But, this is the issue with houses built like this, and why they made it the code for things to be grounded.

    The only reason I'm asking about this, is because of the red light on the UPS that indicates that it's a non-grounded outlet . . . Why will the UPS work, when that light is on? It seems like you're doing something dangerous . . . Maybe you are, but it's not a "no starter" . . . Just some education is needed, so you understand the risks, and how they've learned some things, since houses started being wired for electricity - your whole house has an potential safety risk, if it is not grounded to a stake pounded in ground outside of it.

  • Slack5537

    Ok, I've looked into this.

    Short version (from below)

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    A GFCI only protects between hot and ground, so if there is no ground, there is no benefit - Don't use with and un-grounded 2-prong

    The ground wire gives you "lightning protection". If you just look at statistics, there's not much to worry about.

    System Grounding is NOT a protective measure against a direct lightning strike on your home.

    If you suffer a direct strike, that small bare copper wire will not save you.

    Grounding of an electrical system should not be confused with "lightning protection."

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    1989-2018, 43 lightning fatalities per year (30 years)

    2004-2013, 33 people were killed annually (10 years)

    2009-2018, 27 lightning fatalities averaged (10 years)

    Only about 10% of people who are struck by lightning are killed, 90% get various degrees of disability

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    Grounded outlet required? . . . [GFCI] It only gives protection between the hot wire and ground. No protection between Hot and neutral as the same power going out is coming back. It is when there is an unbalanced load that they shut down . . . If you are saying the above is incorrect well sorry I disagree. If you get between the Hot and neutral the system does not know if you a Person or a light bulb . . . https://forum.nachi.org/t/grounded-outlet-required/26449/8

    Are Ungrounded Electrical Outlets Safe . . . The grounding conductor wasn’t introduced until ~1962 in Louisville, KY . . . a ground wire is not needed for a 120v circuit to function. In fact, there are lots of things you plug into your electrical system that doesn’t use the 3rd pin at all. Lamps, cell phone chargers, and toasters only have two prongs on their cords. However, there are lots of other items in your home that do utilize the ground as a safety measure. Things like refrigerators, washing machines, computers, and TVs have grounded cords. The grounded cords typically show up on items that have a metal case or have sensitive electronics inside them . . . the “ground” we are talking about is technically known as an equipment ground. There are system grounds (power company side of things), and equipment grounds (your house side of things) . . . Grounding is in place to protect us from faults (bad things within an electrical circuit) and damage from lightning strikes. Faults just happen. Electrical motors go bad, wires break, etc. Lightning strikes also get filed under “it happens.” According to NOAA, there are 25,000,000 cloud-to-ground lightning strikes every year . . . Lightning Strikes - 1 out of every 200 houses will be struck by lightning. This is according to the National Lightning Safety Institute. Lightning is an extremely powerful, high-frequency blast of DC voltage, which is capable of devastating damage when you get hit by a direct strike. However, you do not have to suffer a direct hit to have bad things happen. When lightning hits the ground it pushes electrons in all directions. If your house happens to be close enough to this strike, the voltage can jump to the building. This is known as side flash. Now that stray voltage is in the building (on the plumbing pipes, in the wires, etc.) We ground the house to help this voltage get to where it wants to go . . ..the earth (or ground). In other words, we connect all the conductive materials in the house and terminate them to a single point- the ground rod near the electrical panel, or other means (like a water pipe that runs through the yard.) . . . Side Flash - Electrocution - Side flash is what happens when an indirect lightning strike happens and the stray voltage from the strike jumps to conductive things inside the house (like plumbing parts and wiring). If you happen to be standing close to one of these things like an ungrounded outlet, or a steel post in your basement, it could jump over to you and cause you to become electrocuted . . . Side Flash - House Fire - Take the same concept as above with side flash, but you place a combustible material in the mix and you could have a house fire. Even worse, you get electrocuted, you burst into flames, and it sets your house on fire. Hey . . .it could happen . . . System Grounding is NOT a protective measure against a direct lightning strike on your home. If you suffer a direct strike, that small bare copper wire will not save you. Grounding of an electrical system should not be confused with lightning protection. The bottom line with a direct lightning strike near or on the house—you simply have to fix whatever gets broken or bury whoever dies . . . https://abihomeservices.com/are-ungrounded-electrical-outlets-safe/

    Grounding - Safety Fundamentals - YouTube . . . Learn Grounding - Safety Fundamentals with code expert Mike Holt in this excerpt from his best-selling library - Grounding vs. Bonding DVD program. For over 40 years Mike Holt Enterprises has been providing quality electrical code training to help electrical professionals learn the code, prepare for exams, and improve their electrical knowledge . . . https://youtu.be/mpgAVE4UwFw

    2015 U.S. Lightning Deaths | The Weather Channel . . . NOAA says that during the 10-year period of 2004-2013, 33 people were killed and 234 were injured by lightning strikes annually . . . On average, lightning strikes are fatal to about 10 percent of people who are struck. The remaining 90 percent survive, however they often suffer from an array of long-term, often debilitating symptoms . . . https://weather.com/storms/severe/news/united-states-lightning-deaths-2015

    How Dangerous is Lightning? . . . According to the NWS Storm Data, over the last 30 years (1989-2018) the U.S. has averaged 43 reported lightning fatalities per year. Only about 10% of people who are struck by lightning are killed, leaving 90% with various degrees of disability. More recently, in the last 10 years (2009-2018), the U.S. has averaged 27 lightning fatalities . . . https://www.weather.gov/safety/lightning-odds

  • UnexpectedBill

    Circuit breakers are not fast acting devices. It's extremely unlikely that a surge of any type will trip one.

    A GFCI actually does provide a benefit even without a safety ground.

    Where a GFCI will turn off power, a safety ground will divert it, hopefully to a place where it can be safely dissipated without harming anyone or anything. The two different approaches accomplish the same basic thing, from a safety perspective.

    A GFCI can't help dissipate excessive electrical energy from a surge or spike. That's not the problem it solves.

    (There is some truth to the notion that you'd be in trouble, even with a GFCI, if you had somehow become connected to both the live and neutral conductors of an electrical circuit. Even in that scenario, you're still grounded to some degree because you're, well, standing on it. It may not be a good connection, but it is reasonably likely that enough electricity will "leak" through you to ground, the GFCI will notice this little bit of electricity that didn't come back and trip. You may not enjoy the experience, but it's pretty likely that you'll survive it.)

    Nothing can protect against a direct lightning strike. Even "close calls" may prove too much for the protections available in a surge suppressor of any kind. Surges come from many more places than lightning. Most are quite small, short in duration and just a fact of life for anything that is attached to the power line.

    The components in your UPS are designed not to burn easily or sustain a flame. It's possible to make them burn, but quite difficult. Its casing was also designed to contain failures, including fairly violent ones. Whenever I have seen damaged surge suppression components, they took on a sort of ashen grey appearance but were still physically intact.

    I am not exactly certain when branch circuit grounding became commonplace and expected practice across the entirety of the US (or any other part of the world). The service panel in my home dates from 1938 and has a grounding terminal which is connected to a buried ground rod. What it doesn't have is any direct provision for branch circuits to be grounded.

    The long and short of it is that you should arrange to have the wiring in question upgraded with a safety ground as soon as you can. Your UPS will function, but the warning light is telling you that its protections against surge energy are not working at peak capacity. It's not telling you that a fire is imminent or even likely.

  • Slack5537

    Thanks for the info, helps a lot!

  • Slack5537

    With a 2-prong outlet, un-grounded, with a plug-in GFCI . . . Hypothesis:  There is some benefit from using the GFCI:

    . . . it is reasonably likely that enough electricity will "leak" through you to ground, the GFCI will notice this little bit of electricity that didn't come back and trip

    I think this is the reality:

    You may become the ground

    . . . but the GFCI _only_ looks at the connection between the hot wire and ground wire

    . . . It won't see any change with the ground wire, because there is no ground wire, in this scenario

    . . . So the GFCI would not trip

    . . . So, there is no added safety by using a GFCI in this scenario

  • Slack5537

    Can anyone verify this:

    You may become the ground

    . . . but the GFCI _only_ looks at the connection between the hot wire and ground wire

    . . . It won't see any change with the ground wire, because there is no ground wire, in this scenario

    . . . So the GFCI would not trip

    . . . So, there is no added safety by using a GFCI in this scenario

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