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Grounding and bonding
Posted by Billhart  on October 29th, 2007 08:11 PM
In reply to Thank You, One more question by Unregistered-repetereed on October 29th, 2007 04:21 PM [Go to top of thread]
"Where I work to keep noise down on our communications circuits we always have #2 green on isolated ground buss and bond neutral to ground in the meter panel only"
Code allows the ground electrode conductor to be any place from meter through to the main disconnect. You really don't need to keep the neutral and ground electrode system isolated anyplace in that area. Although the attached artical does not recommend.
However, sub-panels must have an isolated neutral bus for several safety reasons.
Also it has been found that in most cases isolated ground receptacles don't provide any advantage to "modern" computer equipment. But might is special sensitive telemetry systems where very, very low signals are piped through a building.
" Good articles. Is the multiwire circuit any reason why my grounds weren't hooked up at the outlets?"
Except for isolated ground receptacles all grounds, even if from multiple circuits, are to be connected to gether in each box and to the receptacles, lights, and switches (for new switches).
"On my meter panel at the house there is no ground (just neutral), and on my neutral/ground bus (in breaker box)my ground wire is a 10 or 12 gauge solid going to my water pipes."
If you water supply is metallic and under ground for a lenght of at least 10 ft then it must be used as a ground electrode. If the external portion is not metallic, but the internal is metallic them it must be bonded. In either case the connection must be made within 5 ft of where the pipe enters the house.
Bunch of special cases and alternate ground electrode. But in almost all cases for a home an 8ft ground rod(s) is also used.
And under current code if the ground electrode does not test for less than 25 ohms a second ground rod, no closer than 6 ft, is needed. That requare a sepecialisted test and is usually not done.
Look at your meter. If you have 1/2 conduit running down from it will have a ground electrode conductor in it and a few inches under the ground it will connec to the top of the ground rod.
The way that the ground conductor is sized is based on the size of the feeder wires.
But based on common practices I have sized them based on size of the service.
100 amp - #8 copper
150 amp - #6 copper
200 amp - #4 copper.
http://www.selfhelpandmore.com/homewiringusa/2002/maindwelling/meter/index.htm Was this post helpful? Yes: or No:
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