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#27663 - 07/27/03 03:24 AM Grounding problem concerning a UPS  
sss  Offline
Junior Member
Joined: Jul 2003
Posts: 2
Mobile, AL, USA
Hallo Everyone. I am kinda new to the forum here but I do have a bit of experience in Electrical...actually more of Electronics really.
Ok I'll get straight to the point here...I live in the US in a pretty old house that has only two pin outlets (110v) all over the place. I changed some of the outlets to three pin recently, but I noticed that there is no ground, so I went ahead and just used the Live and Neutral without the ground, so none of my grounds are connected...I needed the three pin outlets to plug in stuff that had three-pin plugs. So the sockets just have the Live and Neutral, though I did notice a grounding rod outside the house going in to the Distribution box outside with the meter...
Ok I then recently bought a UPS, and upon connecting it, it won't work and an indicator showing that there is a fault in the buliding wiring lights up, I checked the manual and it says that it (the error indicator on the UPS) will light up if the Live and Neutral are inerchanged or there is no ground. I am pretty sure its the ground issue, since I know there is no ground.
Now my question is this, what would you suggest I do to have a ground even if it is just on one outlet just so that I can have the UPS running...the house owner wouldn't help me saying they can not do anything, so I am pretty much on my own here. A friend of mine told me that since there is no ground wire, I could short out the neutral and ground in the outlet to get the UPS running, but I am a bit scared to do that, lest it blow up the UPS or something else in the I wanted to find out first if it will be ok for me to short out the neutral and ground at the outlet

Please any response or suggestion will be highly appreciated!!!
Thanking you in advance,

Work Gear for Electricians and the Trades

#27664 - 07/27/03 06:38 AM Re: Grounding problem concerning a UPS  
zapped208  Offline
Joined: Feb 2003
Posts: 196
Somewhere in USA
sss,- yes you need to install a ground. You can do this 2 ways. Install a new circuit from panel ,3wire,hot- neutral- ground,to a new recep,or get some #12 green THHN SOLID wire and go from the ground screw of the recep to the neutral bar in the panel. The first method would be the the better choice. Of course instlled by an electrician.

Shoot first, apologize later.....maybe

#27665 - 07/27/03 10:42 AM Re: Grounding problem concerning a UPS  
George Corron  Offline
Joined: May 2001
Posts: 717
Lorton, Va USA
You also may have your house wired in BX (Armor Clad Cable) which is grounded by the metallic skin of the cable, and you would not see a ground conductor in the box. If this is the case, what you need is a wire from the box to your outlet to set things right. Most suppliers sell these as green wires with a green screw on the end.

You may have a multitude of problems as well, though, I urge a lot of caution.

#27666 - 07/27/03 06:58 PM Re: Grounding problem concerning a UPS  
Ron  Offline
Joined: Mar 2002
Posts: 582
White Plains, NY
If as described you have BX cable (armored Cable), you would need to know if there is a bonding strip/wire in the jacket. If it is old style BX, then there will be no bonding strip and you cannot use it for grounding.
Your best bet is to add a new circuit with current style wiring. Adding a ground wire only is almost as tough as a new circuit all together, so just run the new circuit.

In addition, you should switch back the two prong receptacles, as it is not legal to just replace them with a three prong, unless you install a GFCI receptacle at the beginning of the circuit to protect the down stream. Then you would put a label on each downstream three proong recept indicating it has no ground.

[This message has been edited by Ron (edited 07-27-2003).]


#27667 - 07/27/03 08:01 PM Re: Grounding problem concerning a UPS  
Scott35  Offline

Broom Pusher and
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Best suggestions here push towards the new Dedicated Circuit - and as mentioned, if you were to bond the Receptacle to the Equipment Ground at the panel with one #12 cu, you may as well bring two more #12 Conductors with it and have a nice clean, Dedicated Circuit to drive your PC and Peripherals from.

This Dedicated Circuit could also eliminate UPS cycling, due to Transient Voltage sags / dips caused from other loads connected to the same Branch Circuit (like when an Electric Motor starts, it causes a temporary drop in the intensity of Incandescent lamps).

The UPS will operate (and the PC also) without an Equipment grounding Conductor, but the benefits of noise rejection, sheilding and most of all - almost zero shock to ground hazard, will require the EGC connection.

Lastly, as mentioned by others, when you replaced the 2 wire Receptacles with three wire ones, you have setup a potential hazard for equipment with three wire cord caps (Plugs) which have metal cases (or some other method for leakage currents to flow through a person's body from an internal wiring fault).
Either replace the Receptacles with two wire ones, or protect the "String" of three wire Receptacles via a GFI Receptacle (or Circuit Breaker).
The GFI Receptacle method would require placement of the GFCI type Receptacle device at the first outlet of the Circuit (first outlet from the Panel). Place the 2 wire Circuit coming from the Panel on the "Line" side of the device. Place the outgoing 2 wire Circuit on the "Load" side of the device. Now the Receptacles which are "Downstream" from this outlet (along with the GFI outlet) have Ground Fault protection. Be sure to add the "No Equipment Ground" stickers, which come with the GFI device, to the protected Receptacles.
If you choose the GFCI Circuit Breaker option, just find the 2 wire Circuit for this string of Receptacles (the Black and White wires), and run them through the Breaker.
If the Circuit is a three wire / Multiwire Circuit, cannot use a 1 pole GFCI unit (need a 2 pole unit or resort to the GFI Receptacle method).

This information is being given to you as a reference to what options you have. Strongly suggest you have this work performed by / under the supervision of a Qualified Electrician!!!
Working in live Panels is VERY DANGEROUS!!! It only takes one slip-up, and before you even realize it, things have taken an ugly turn!!!
Incorrect connections of Circuitry will result in safety hazards plus damage to equipment.

Hire a good Electrician to do this work for you, and observe the installation being performed to see how its done.

Be sure to mention to the Electrician you would like to observe the installations!!!

Nothing makes a Technician more nervous than having someone watching over them, as if they are "Supervising" the installation. Let the person know that you are interested in observing the correct install methods, and chances are the person will not only feel comfortable with you observing, but go as far as describe the items and steps involved.

Works out for both of you [Linked Image]

Good luck.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#27668 - 07/27/03 08:16 PM Re: Grounding problem concerning a UPS  
Happy Birthday iwire  Offline
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
As I am reading this:

This Dedicated Circuit could also eliminate UPS cycling, due to Transient Voltage sags / dips caused from other loads...

I am listening to the relay in my UPS cycle as the Air Conditioner kicks on. [Linked Image]

Dedicated circuits but POCO has me on same small looking transformer with at least 8 other houses. [Linked Image]

Bob Badger
Construction & Maintenance Electrician

#27669 - 07/27/03 10:52 PM Re: Grounding problem concerning a UPS  
LK  Offline
Joined: Jan 2003
Posts: 1,429
New Jersey
That strip in the BX is used as a leader in the cable mill, has no bonding or grounding use at all. The BX without the leader can support a ground.

#27670 - 07/28/03 05:55 AM Re: Grounding problem concerning a UPS  
Happy Birthday iwire  Offline
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA

BX, or AC Cable as the code would call it is required to have an internal bonding strip look at this code article

320.100 Construction.
Type AC cable shall have an armor of flexible metal tape and shall have an internal bonding strip of copper or aluminum in intimate contact with the armor for its entire length.

This is not to say you must do anything with this bonding strip, I have seen them landed on ground bars but that is not required.

The reason for this bonding strip from what I have been told, is that old armored cable without the strip could when subjected to fault current heat up red hot like a toaster element.

Bob Badger
Construction & Maintenance Electrician

#27671 - 07/28/03 09:20 AM Re: Grounding problem concerning a UPS  
Ron  Offline
Joined: Mar 2002
Posts: 582
White Plains, NY
The bonding strip in AC cable is just that, for bonding. It assists the jacket to reduce arcing between adjacent wraps of the jacket material.


#27672 - 07/28/03 11:18 AM Re: Grounding problem concerning a UPS  
LK  Offline
Joined: Jan 2003
Posts: 1,429
New Jersey
You are both correct, however ron's point about don't use this cable for a UPS is the best answer. Check with the cable maker of the AC cable. We had a great discussion at the trade booth on just this subject.

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