I would like to run a ground wire in conduit(with other conductors) to a surge protected device.How can I go from the conduit to a plumbing ground clamp?
I need to run a 8ga ground to an electronic control panel for it's required surge protection.Requires a ground rod or plumbing meter ground.I want to run this ground and the hot,neutral conductors in the same conduit,as the feeds will be passing past the water meter on the way to the electronic control panel anyway.
Just want to be sure of a code compliant way to Tee out of the conduit to make this connection to the water meter ground clamp
The bonding conductor that is to land on the grounding electrode system does not have to be installed in a raceway unless it is subject to physical damage.
Should you decide to install the conductor in a pipe and that pipe is a metal raceway then the metal raceway will need to be bonded to this conductor on both ends. This can entail a lot of extra work and expense.
If in your opinion the conductor needs to be protected then install it in a nonmetallic raceway and the requirement to bond to the raceway is lifted.
By installing a junction box you can then exit the raceway via the box.
Yes physical harm of the wire is a concern.
The feeds are to feed out of a GFCI receptacle in a surface mounted 4" steel box.
Am I permitted to run NMT(PVC) conduit straight out of this box?
This box is located in a mechanical room with fire-rated drywall and doors and the surface mounted conduit is all EMT.
I would like to transition from EMT out of this room to NMT,but I would prefer to do this outside of this room.
Yes,the water supply for the ground wire is in close proximity to the GFCI receptacle/steel box.
Last edited by Juan for the road; 08-11-2008 at 09:58 AM. Reason: added info
Is this residential or commercial?
Rez...how would the codes differ depending?
It is okay in most areas of the United States for a homeowner to endanger their own lives and the lives of their families as long as they are making installations in a home that they own but they are not allowed to make installations in rental or commercial properties.
I appreciate your concern.
Let me be specific at this point.
I would like to come out of a 4" box containing a GFCI protected receptacle(which is wired in series with 3 other receptacles).Everything is surface mounted,run in 1/2" EMT.Located in a fire-rated mechanical room.I plan on coming straight down the wall,from that 4" steel box with 1/2" EMT containing 3 wires:hot,ground and neutral,all 12ga THHN.
The EMT will then procede to a box approx 12" from the floor,where an 8ga THHN wire will enter the box,having been clamped to the copper water supply before the water meter(located about 18" from the box).I will clamp the 8ga ,where it enters the box with a NM butterfly style clamp(probably wont clamp much actually).
At this point,the EMT will travel down thru the floor in a tightly drilled hole,sealed with fire-rated caulk, to the crawl space beneath.I will run the EMT into a steel 4" box containing the 4 wires.I would like to,at this point,come out of the steel box with NMT(PVC),1/2" and procede to the outside to another box,mounted to the exterior of the house,a weather proof plastic box.Then from there,1/2" NMT to the Control Panel(with a max draw of 1.5a).Control Panel is hard-wired.
The 8ga,is specifically for surge suppression.I could set a dedicated ground rod,however the sandy/gravelly soil makes for an unreliable ground here.I much prefer a copper water supply ground.
NMT will have to 90* once in the crawl space,will use the proper sweep.Straps every 32".
I will total the individual wire fill to be sure that 1/2"conduit is OK.
You say the #8 is only for surge suppression. From that I infer that you have a code-compliant Grounding Electrode System and the #8 you are asking about is not the Grounding Electrode Conductor.
Since you are running this in EMT, the EMT is/should be bonded to the grounding system running back to the service, maybe through a subpanel or maybe not. EMT is an acceptable Equipment Grounding Conductor so it doesn't require a separate grounding conductor (a "green wire") for the circuit.
I am not aware of any code provision that prevents you from running an additional #8 copper conductor from any piece of equipment to any other piece of metal in the facility, except that it may not be connected to an ungrounded (hot) conductor or to the grounded conductor (neutral). I also don't know of any provision that would permit you to omit the equipment grounding conductor ("the green wire") from any circuit that you install.
Here is the code references;
ARTICLE 285 Surge-Protective Devices (SPDs), 1 kV or Less
285.28 Grounding Conductor Connections and Enclosures.
Except as indicated in this article, SPD grounding connections shall be made as specified in Article 250, Part III. Grounding conductors installed in metal enclosures shall comply with 250.64(E).
250.64(E) Enclosures for Grounding Electrode Conductors. Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. Nonferrous metal enclosures shall not be required to be electrically continuous. Ferrous metal enclosures that are not physically continuous from cabinets or equipment to the grounding electrode shall be made electrically continuous by bonding each end of the raceway or enclosure to the grounding electrode conductor. Bonding shall apply at each end and to all intervening ferrous raceways, boxes, and enclosures between the cabinets or equipment and the grounding electrode. The bonding jumper for a grounding electrode conductor raceway or cable armor shall be the same size as, or larger than, the enclosed grounding electrode conductor. Where a raceway is used as protection for a grounding electrode conductor, the installation shall comply with the requirements of the appropriate raceway article.
For more help see this
Thank you for the code refs,pretty much answers it.
Yes,the 8ga is solely for surge protection,to protect the electronics,apart from the electrical.
The enclosure itself,of the control panel, is plastic,rated indoor/outdoor.
I will feed the panel from the GFCI receptacle,out to EMT down to the crawlspace to a steel box,grounded with the EGC. I will then transition to !/2" PVC conduit to the outside and to the enclosure.
I'm going to clamp the 8ga to the water supply in the crawlspace to simplify things and run it in a seperate 1/2" conduit,it's a short easy run.Conduit is just neater and takes the guess work of what the wire is,in the future.
Is it OK to just bring the 8ga from the clamp directly into a piece of conduit,without any box or othe transition?
If I had a situation where I had a NM cable,and wanted to get it into PVC conduit for protection purposes,say near an attic scuttle,can I just put it in there(provided it meets the conduit fill table)?
If you install this #8 in EMT and a metal box and do not bond it back at every point where in enters and leaves the metal raceway and enclosure then in the event of a surge due to lightning the #8 is useless and the surge protector will do nothing to protect anything.
FYI - The reason both ends of the conduit must be bonded is to prevent what is called "inductive choke". These gizmos or anything behaving in this manner restrict alternating current. And home electricity is alternating current. So you want your house current to be able to "flow" through the ground wire unimpeded.
Here is more on this...
If I run the #8 in PVC conduit (for protection),I am OK?