bit of confusion now...

Discussion in 'Electrical Forum discussion & Blog' started by solutions, Mar 18, 2008.

  1. solutions

    solutions New Member

    Messages:
    22
    As per a previous thread i started re: re wireing

    Actually it should be grounding a un grounded house short of a complete re wire... Anyway what i mean by confusion is this..I have talked to several qualified,licensed,experienced etc. electricians.
    1. Some, say all receptacles in the dwelling need GFCI's,

    2.some say the first receptacle in each circuit needs a GFCI, wired in so it protects all other receps. downstream in that circuit.A sticker stating "No equipment ground" and visable also needs to be in place all receps.

    3. One electrician said it is wortless and a waste to try and acheieve a ground with GFCI's.

    I realize GFCI's may not give me a "proper ground" but as long as they make for safer wireing, and protects all equipment plugged into those receptacles and NEC recognizes it as acceptable code compliant etc. I am favoring the idea. Plus i am told the existing three prong outlets now in place can be kept as long as they are protected as mentioned above in 2.
  2. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Number 2 is the safest without a rewire (assuming you don't have metallic conduit). Putting some devices (such as a flourescent light) on a GFCI can lead to nuissence trips, in the case of number 2 it would shut off anything "downstream." My opinion...

    Jason
  3. jdoll42

    jdoll42 Computer Systems Engineer

    Messages:
    68
    Location:
    In Illinois near St. Louis, MO
    If you wire them in series properly, the first GFCI in the chain will protect anything that follows it.

    Bingo! Your GFCI's should also come with stickers that you can put on the outlets beyond the GFCI to indicate they are also GFCI protected.

    I'm not an electrician, but don't GFCI's work off of the ground wire (GROUND fault circuit interrupter)? If none of the outlets have a ground wire, isn't the GFCI pretty much useless?
  4. pudge565

    pudge565 New Member

    Messages:
    24
    no they dont work with the ground this is a typical misconception. it detects ground faults by measureing the crurrent between the hot and neutral wire a difference of 4-6 miliamps will trip the gfci.
  5. jdoll42

    jdoll42 Computer Systems Engineer

    Messages:
    68
    Location:
    In Illinois near St. Louis, MO
    Ok. I get it now. It detects the current going to ground ELSEWHERE on the circuit instead of back through the neutral wire, thus the Ground Fault part. If the current on the hot wire doesn't match the current on the neutral wire, it's going somewhere it's not supposed to.

    Well you learn something new every day. Thanks for the clarification!
    Last edited: Mar 18, 2008
  6. jbfan74

    jbfan74 Electrical Contractor

    Messages:
    131
    Location:
    Newnan, GA
    Also, putting in gfci's will not offer protection for your equipment!
  7. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,266
    Location:
    New England
    Some electronics use the ground wire to help shield or filter noise propagation or reception from interferring with things. A GFCI won't help that if there isn't a real ground, but from a safety viewpoint (i.e., to keep from getting shocked), they work great. Depends on what you are trying to do...a complete rewire is the better way to do things, but you'd probably find you need to add a bunch more outlets and maybe circuits, too and the costs can be quite high. You have to decide what good enough is...
  8. kd

    kd New Member

    Messages:
    207
    GFCI will trip at 5 mili amps, not 4.
  9. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    Wrong answer!

    GFCI can not trip at more than .005 amps but can trip at lower amperages. It will depend on who made it.
  10. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT
    FWIW, most home appliances are only two wire anyhow, so why not just replace your existing receptacles with two wire receptacles? Then either rewire or install GFCI's where you actually need a 3 wire receptacle.
  11. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    Use GFCI breakers.

    You will save hours of trying to find out what feeds what.


    You still have no ground but you eliminate the chance of being hurt by a fault to ground.



    Most surge protectors wont work without a ground.
  12. pudge565

    pudge565 New Member

    Messages:
    24
    i believe that i read the 4-6 mili amp thing in mullins text residential wiring 15th edition not quite sure if it was or not i will check on tuesday wen i go back to tech.
    Last edited: Mar 23, 2008
Similar Threads: confusion
Forum Title Date
Electrical Forum discussion & Blog Derating Confusion Dec 18, 2012
Electrical Forum discussion & Blog Dimmer switch confusion Dec 13, 2010
Electrical Forum discussion & Blog Ground wire confusion Jun 10, 2010
Electrical Forum discussion & Blog 200 amp upgrade confusion Mar 15, 2010
Electrical Forum discussion & Blog To avoid any fruther confusion.... Sep 8, 2008

Share This Page