Grounding grid

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MikeBuck25

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On a job I am doing they are requiring the HMWPE type insulation w/ green stripe.. I was just wondering where in the code does it require the green stripe or green insulation for the grounding grid? The size of the wire is 2/0 awg. All help is appreciated.
 
what we did was accidentally put in Black HMWPE 2/0 awg wire in the ground for the grounding grid on the site. Usually it has a green stripe on it. I need to know where in the code it is required to have that green stripe. I know #6 and smaller must be completly green for the equipment gnd.
 
What is HMWPE? What is the purpose of this "ground grid"? Generally, only equipment grounds need to be green colored. A ground electrode conductor, or a pool/barn equipotential grid, don't have any color requirements.

Was there something in the job spec requiring this green identification (or a referenced spec)?
 
I worked in the design field for 44 years and each project had a plant ground grid that all electrical user's were tied to and without exception the grid conductors were GREEN.

High Molecular Weight Polyethlene(HMWPE) is a tougher than a boot insulation when applied to cable manufacturing and will withstand a lot of abuse.I kinda think it is overkill for a ground grid but hey if thats what is spec'ed give it to'em

dick
 
Tom when copper is buried without insulation it is open to a lot of chemicals within the soils in and around refineries,chemical plants etc and the things sometimes start the deteriation process faster than wanted,,,,,,, basically just a precaution

dick
 
dicklaxt said:
Tom when copper is buried without insulation it is open to a lot of chemicals within the soils in and around refineries,chemical plants etc and the things sometimes start the deteriation process faster than wanted,,,,,,, basically just a precaution

dick
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But if the ground grid conductor is insulated, what good would it be? Isn't ground grid conductor supposed to be in contact with the earth?
 
No not as a norm.,,,,,,,,,,,,,,,,well any that I ever worked with,many ground rods along the way say every 75 feet in coastal areas.

dick
 
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dicklaxt said:
No not as a norm.,,,,,,,,,,,,,,,,well any that I ever worked with,many ground rods along the way say every 75 feet in coastal areas.

dick
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OK, I am thinking of ground grids at a substation where the 4/0 conductor is bare and attached to rods every 40-50 feet or so..
 
Yes that is so but sometimes they too are insulated and are included as a sub loop within the plant ground loop with a minimum of two connections. In fact there are many times when mutiple process or manufacturing units have their own grid and all grids in the plant proper are tied together by a minimum of two ties so that there is always a continious ground loop in case one tie is severed.A lot of that stuff is spec or client oriented.

dick
 
dicklaxt said:
Tom when copper is buried without insulation it is open to a lot of chemicals within the soils in and around refineries,chemical plants etc and the things sometimes start the deteriation process faster than wanted,,,,,,, basically just a precaution

dick
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But insulation is still removed to connect to ground rods or other electrodes, what keeps from deteriorating at those points?

If deterioration is a big problem, maybe different materials need to be used.
 
Rods/taps are connected with Cadwelds and insulated with putty and vulcanizing 15KV Tape,lots of different things are used but thats was one of the better methods. Test Wells(rods with bolt on connectors) are used say one per each 150' x 200' area depending on soil resistivity,if it's high then a second rod is coupled on and driven to 20 foot depth . Its a crap shoot at times but a proven method.You never know how a chemical spill and runoff will affect the design.

dick
 
MikeBuck25 said:
what we did was accidentally put in Black HMWPE 2/0 awg wire in the ground for the grounding grid on the site. Usually it has a green stripe on it. I need to know where in the code it is required to have that green stripe. I know #6 and smaller must be completly green for the equipment gnd.
Click to expand...
There is no insulation (or trace) color requirement for grounding electrode conductors or [electrode] bonding jumpers.

By implicit default, the insulation (or trace) coloring cannot be of a method reserved for grounded circuit conductors.
 
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