house ground question..

lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
Hi

i recently discovered our house ground (grid connected AC) wasnt working.. its connected to a copper water pipe about 5' below ground level through our field stone foundation.. it had corrodoed completely off... this morning i got a new zinc plated ground clamp, sanded the pipe to expose some shiny copper and reconnected it. I tested some of the outlets upstairs that i jnow have properly grounded outlets and it seems all good. I have two questions:

can i coat the ground clamp and around it on the pipe in petroleum jelly to prevent more corrosion like we do on battery terminals?

and:

I also have an offgrid solar system with a pure sine wave inverter that has no grounding on that system of any type.. i was thinking of connecting the ground cable on the sine wave inverter to my houses's ground which i now know is working.. is this ok? basically i want the ground plugs working on my solar's AC as i run alot of expensive equipment on it: computers, etc..). id like to see my computers "line fault" light go off... and also to have the ability to plug into the ground for static discharge if needed when working on electronics/computers..

thank you!

Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: house ground question..

    hi matt,
    that's a good question if it's legal to do that or not as i'm not sure. i do know that the connection can loosen and if it did the coating material could migrate between the connector and the rod. maybe use 2 connectors and retighten them after at least 6 months before applying something like that. i do assume this will be underground and not visible to an inspector otherwise let it go if above ground and just check it for tightness and condition every so many years.

    ground connections are supposed to be carried forward to the main breaker box from a gt inverter. this means for a 240vac gt inverter that there will be 4 wires going to the main breaker box. 2 hots, 1 neutral, and 1 ground. btw the neutral to ground connection must only occur in the main breaker box.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: house ground question..
    lamplight wrote: »
    Hi

    i recently discovered our house ground (grid connected AC) wasnt working.. its connected to a copper water pipe about 5' below ground level through our field stone foundation.. it had corrodoed completely off... this morning i got a new zinc plated ground clamp, sanded the pipe to expose some shiny copper and reconnected it.

    There is a large part of your problem! A zinc coated ground clamp is meant to be used on galvanized water pipes. For use on a copper rod or pipe you need a brass or bronze ground clamp.
    Electrolytic (galvanic) corrosion between the zinc and copper will eat away at all points where the two touch. It will be strongest if they get wet or exposed to high humidity, but that is not necessary for damage to happen.
    SMA SB 3000, old BP panels.
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    ok I'll go get another clamp that's not zinc.. hardware store had no idea... I thought I'd mention that just for that reason.. it's working fine but I understand may corrode.. will go get something else tomorrow..

    Neil re: my inverter it is not grid tie at all in any sense.. it's just an offside sine wave inverter that's connected to solar batteries.. the ac output from that is in no way connected to my grid tie AC.. so given that...,can I share the ground?
  • RCinFLARCinFLA Solar Expert Posts: 1,474 ✭✭✭✭
    Re: house ground question..

    Yes, you need a brass clamp. Zinc and copper along with some moisture make a good battery.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: house ground question..

    "Neil re: my inverter it is not grid tie at all in any sense.. it's just an offside sine wave inverter that's connected to solar batteries.. the ac output from that is in no way connected to my grid tie AC.. so given that...,can I share the ground?"

    well that depends. if they already connect the neutral and ground at the inverter then that's a no go and to disconnect it and run the wires separately should not be problematic with that particular inverter for if it is problematic then don't do it. a separate ground wire and rod is a possibility though if it is in no way connected to the other normal ac wiring. you need to research your manual as to what it says on grounding before even thinking of what this ol fart says.
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    thanks neil.. I did look at manual before posting.. I didn't understand what it was saying.. will post what it says re: grounding..
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..
    inetdog wrote: »
    There is a large part of your problem! A zinc coated ground clamp is meant to be used on galvanized water pipes. For use on a copper rod or pipe you need a brass or bronze ground clamp.
    Electrolytic (galvanic) corrosion between the zinc and copper will eat away at all points where the two touch. It will be strongest if they get wet or exposed to high humidity, but that is not necessary for damage to happen.
    RCinFLA wrote: »
    Yes, you need a brass clamp. Zinc and copper along with some moisture make a good battery.






    From this Thread:
    http://forum.solar-electric.com/showthread.php?16734-Green-Water-This-can-t-be-good&p=126161#post126161

    Brass IS Copper & Zinc
    Bronze IS Copper & TIN
    All vessels (boats) that have brass thru-hulls ,will not be insured if a claim is made 4 a flounder. Bronze fittings below water line.

    ~~~~~~~~~~~~~~

    And from being a sparky tech (IBEW) Bronze is the clamp only .. all other metals could fail an inspection
    Brass is not allowed in Code.

    VT

    Edit add:
    As I read here, Fuels /CNG & LPG need the correct gas piping & lines plus FORGED nut's ..
    If you pay for insurance , then build to code, cuz the fittings don't burn , and inspectors are sticklers !!

    Just sayin

    YMMV
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    ok.. guess I better find out what code wants for MA
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..

    Attachment not found.

    This is one I was referring to : link is web site Sir.

    VT
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    hi

    so copper clad steel?? ill see if they have it locally and order if not.. i also put a call into the electrician ive used before to ask what he recommends/code requires.. thanks... why dont they just have solid copper??

    thanks!

    CDN_VT wrote: »
    Attachment not found.

    This is one I was referring to : link is web site Sir.

    VT
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: house ground question..

    pure copper is too soft.
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..

    Neil is correct , the one I posted should be made from bronze , and is for copper water pipes ground bonding.
    I prefer the external line to a dedicated grounding rod , but that holds for new construction mostly. Being so picky must see ease of install or repairs within codes.

    VT
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    hi

    so that's what inetdog said: bronze. I'm so confused .. a local electrician today called back and said to go to a particular local electric supply place as they sell copper ones.. can you clearly confirm: bronze is good and code compliant?

    thanks!
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..

    Brass Is shiny , bronze is in-between . Best as As i can describe.

    Yes I can see the difference. I carry a magnetic & a knife.

    Sorry , but the colour / color is one of the basic features , as with Stainless , it's magnetizable till the content of "Nickel" is found . 304-till-429 tells me the content.


    VT

    And yes , Bronze is the code compliant one in MA.
    But saying that , it also depends on what it is hooked to , plus.

    VT
  • lamplightlamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: house ground question..

    you speak about as clearly as a mystic or fortune teller. I appreciate, what I think, is your effort to help.. but if you look at your posts you will see they are unclear as hell. you post a pic and a link to a website saying I should get bronze which in a previous post you said I shouldn't get.. vaguely... English not your native language? forget it. no response necessary.. most others here are great. thanks anyhow
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..

    BUY a code book or HIRE a IBEW electrician . (Union dude)
    Safety is always #1!!!


    See the picture I posted ?? , go to an ACE hardware or a Lowes and find the clamp.

    print the picture in Colour, and then match it with one , THEN go and see a "BRASS CLOCK" , if the clamp is dull & copper based colour & the clock is shinny , you might have a good bronze clamp, Bronze = dark yellow dull ,copper base but no shine .Brass = crap and flash , ZINC is a metal for compost ...You can elect a sacrificial metal',, Zincs for vessels is to save the more expensive $$ metals.

    Remember : Brass IS Copper & Zinc shiny
    Bronze IS Copper & TIN dull & strong + $ over brass

    Best I can help with
    VT

    EDIT ADD:
    Home depot sku= Model: 3110-U-CP | Store SKU: 1000408049

    This is for 1/2 copper water line grounding bond : Attachment not found.
    IBERVILLE
    1/2 In. Ground Clamp Bronze - Bag of 1
    Many older houses used the copper water piping system for the main ground for the systems power panel.
    Very import to have a GOOD ground-s all dimmers & GFI's work as they are design to.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: house ground question..

    tone it down guys as we don't want ill feelings if we can avoid them.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: house ground question..

    Thanks CDN_VT for the clarification on bronze/brass. Some of it I didn't realize, or forgot, having never thought about since school. The magnet thing was a surprise going only by the colour :)

    http://en.wikipedia.org/wiki/Brass

    http://en.wikipedia.org/wiki/Bronze
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: house ground question..

    The magnet "thing" is for stainless ONLY !
    Copper/Brass/Bronze are Non-Ferrous metals & Non- Magnetic

    Ferrous are magnetic , till Ni Nickel is added to make it stainless , 304 type stainless will feel magnetic slightly till 308 to 316 hardly anything, In to the 400's not a bit of feel.
    Since I own a hole in the water (BOAT with a stick pointing up) , Galvanic action is the best at eating money.
    I have "Zinc's" under the water , inside the engine cooling system just for a sacrificial metal.
    Edit add: Zinc is silver in colour , that's why the brass shines , and is weak compared to bronze.
    HTH's.

    VT
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