Shop Products
Houzz Logo Print
reed50_gw

grounding copper pipe question

reed50
13 years ago

We had the grey plastic pipes replaced in our manufactured home with copper pipes about 5 years ago (still plastic coming to house). I'm now finding out that the copper pipes should have been grounded or bonded, and I'm pretty sure they were not. Is this something I need to have done and can someone explain why? Thanks for your help

Comments (23)

  • tom_o
    13 years ago

    Yes, you should bond the metal water pipes to the service. Electrically conductive materials, such as copper water lines, that are likely to become energized are bonded to provide a low impedance path for clearing ground faults that otherwise would energize the materials at a level above earth potential. Metal water lines are considered as likely to become energized.

  • reed50
    Original Author
    13 years ago

    Question (please be patient with a female who's trying to learn): how do my water pipes become energized?

  • Billl
    13 years ago

    Water pipes can become energized when they come into contact with anything in your electrical system or any appliance etc. Just think of all the appliances that are either connect to or right next to water - dish washer, garbage disposal, water heater, washing machine etc. Also, it is pretty common for electrical wires and pipes to run along similar paths.

    Of course, if everything is installed properly and working properly, water and electricity don't come into contact with each other. The grounding is only there "just in case." Eventually though, everything breaks. Grounding everything helps insure that even if something goes wrong, it won't injure you etc.

  • tim45z10
    13 years ago

    I would check and see what kind of fitting was placed at the wire entry and exit points of the copper tube. If there is no protection the copper tube could cut into the wires. Also current flowing through a wire can induce a voltage into the copper pipe.
    Put a ground rod into the ground and clamp a #8 wire to the rod and the copper tube.

  • tom_o
    13 years ago

    The short answer to your question is no.

    The connection to the metal water lines is based on the worst case scenario and the size of the conductor between the service panel and the water line is based on the size of the conductors that make up your service entrance. Generally speaking, for a dwelling, this bonding conductor would be #4 copper for a 200 amp service and #6 copper for a 100 amp service (#8 is permitted for a 100 amp service, but would have to be armored or have some other type of physical protection). These sizes have considerably more capacity than the equipment ground that runs with the circuit feeding your appliances.

  • yosemitebill
    13 years ago

    I think the OP's post may have been misunderstood somewhat. This is a manufactured home and the grey plastic water pipes are polybutylene, which have had a problem with breakage at the fittings. New manufactured home now use PEX. For repairs of the older polybutylene, copper is often used to just get away from the whole problem. So now it appears the OP has had the entire plumbing replaced with copper, but it is still fed by a underground PVC supply at the entry point to the home... much like a stick-built home on a well.

    I don't know the answer to this question regarding "code" on a manufactured home, but it seems like bonding the copper after the transition from PVC would just be a good idea. One bond at that point covers all the updated plumbing. Of course bonding needs to carried across such things as plastic water filters, softeners, etc.

  • scjlikar
    9 years ago

    So I just heard that if there is a grounded electric wire touching a copper pipe it will cause green to appear in the water and if you have colored hair that it may turn a hue of green. Is this correct?

  • Ron Natalie
    9 years ago

    Could it? I guess it's possible. What's more likely to happen is that a tiny pinhole will corrode where the contact is made and the pipe will eventually spring a leak. Even copper-to-copper contact is often dissimilar enough to cause galvanic corrosion over time (I've had pipes corrode at copper pipe hangers). It makes little difference if the wire is grounded or not.


  • weedmeister
    9 years ago

    Grounded copper pipes cause your hair to turn green? That explains the Joker I guess...;)


  • mjsewell1
    8 years ago

    If a copper piping system is not grounded properly and is susceptible to stray currents from adjacent electrical lines how might this scenario affect downstream rubber components within the copper system?

  • ionized_gw
    8 years ago

    mjsewell1, are you asking about rubber washers and other seals in faucets, really downstream like stuff like Fernco fittings, or something else?

  • PRO
    noyb
    8 years ago

    what about if pvc is under the sinks taking water to the sewer & the rest of the pipes are copper except not the incoming water pipe which is plastic?

  • Ron Natalie
    8 years ago

    I'm not understanding your English, noyb, but the answer is simple. Metal (other than gas) piping must be bonded, it matters not if some of the components in the system are plastic.


  • PRO
    noyb
    8 years ago

    thanks-- could metal piping become energized because it is bonded to the house electrical grounding system?

  • Ron Natalie
    8 years ago

    No, the opposite is true. The bonding is to KEEP it from getting energized (i.e., hopefully the low impedance path of the bond will cause the overcurrent device of the circuit that's improperly engergizing the metal parts to trip rapidly).


  • PRO
    noyb
    8 years ago

    thanks-- why wouldn't current go the opposite way? say for example, if lightning strikes the ground rod, could current travel into the piping system through the rod into the clamp wire and the bonding wires into the copper piping?

  • Ron Natalie
    8 years ago

    None of this has anything to do with lightning. A close lightning strike is going to potentially cause probems no matter what. This is to protect building metal from getting energized by the building electrical system. Before you whine that it isn't likely to be happen, TWICE I've caught energized metal structural peices. In one case metal studs in a wall (and a nearby window sill) traded to a frayed piece of NM cable (not the right fitting for passing through the structure) and in another case part of a stage lighting system in a theater.

    The latter could have been dangerous to me as I had touched the energized raceway with one hand and was holding on to a piece of structural steel with the other.

  • PRO
    noyb
    8 years ago

    thanks--is there any best practice or best method to bond the mixed metal plumbing?

  • Ron Natalie
    8 years ago

    All the practice you need is listed in Article 250. Metal piping (other than gas) needs to be bonded to the grounding system. If there are things such as water meters or dielectric unions in the mix, both sides need to be bonded some how.

    If you don't understand Aritcle 250 you have no business working on the electrical system of a building. It's perhaps THE most important aspect of the code.


  • spookyboo
    last year

    the reason why copper water pipes including gas pipes have to earthed is that to eliminate and possible chance of and electrical potential existing eg hotwater pipes are connected to the sink bath taps etc if for any reason they suddenly became live eg faulty electrical boiler the fault current would pass through the earth cable back to fuse board or breaker system and disconnect the voltage if this system was not put in plaace the consequences could be fatal

  • spookyboo
    last year

    this called equipotential they also use crossbondinging on hot and cold pipes plus cross bonding on gas boiler systems this reudeuces the chance of electrocution down to ma bare minimum as it is a legal requirement all modern house have conform to these requuirements either IEE or the latestet regulation book covers all the details but its a bit techinical for the beginner, i must make an additional note most modern water stop tap water systems have plastic pipes these day so any main bonding must be done on the consumers side thats on the copper pipe must be viewable for inspection at all time

  • spookyboo
    last year

    its quite simple really after you got 20+ years experience it just comes natural what should be in place with a simple tests to prove this