Service Change Code Updates??

marxie

Hi All,

It's been a few years since I have done a service change and I need to update the electrical on an old money pit I inherited. Last time I did one was about 6 years ago working for another GC. This house was built in the early 60's and has never been upgraded. I would like to install a 125 amp 20 space service panel. The existing box in only grounded to the cold water pipe. The last time I did this, we installed a 6' copper grounding bar and had to run a #6 copper wire to the water pipe at the point it entered the house as well as ground the water heater to the water. I have UBC and IRC manuals ,but not UEC so I'm not sure if there have been changes.
Also, I live in California which probably makes a difference. I'm just trying to get all my ducks in a row since the power will be totally off. Thanks in advance.

Speedy Petey

Basically you will need two 8' ground rods and a water bond. If the water pipe entering the house is metallic you MUST connect to it within 5' of where it enters the house and jump around any meter or plastic filters.

Here is a very comprehensive guide to residential services base on the NEC:
http://www.selfhelpandmore.com/homew...eter/index.htm

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Electromotive24

I thought you only had to have 2 if you didnt get 23 ohms of resistince in the soil. They also have got to be six foot apart

Speedy Petey

While that is true I am not about to buy the $1000 tester to check for the 25Ω. I'll just sink another ground rod.

I will say, I do not always install two rods. In fact for years I always only did one.
In almost 20 years I have NEVER been checked, or been ask to check the ohms of my ground rods. Only in past years have I voluntarily installed two rods just for CYA reasons.
If I do a servie in a house with a metallic water line coming in I typically just install one rod. If there is no water pipe electrode I do two.

We will be adopting 2005 around here soon so no more rods in new houses. Just a Ufer.

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CE1

All the the power companys in my area require two ground rods no matter what. So you need to check with your local power company as to what THEY want.

Electromotive24

That is true I have yet to install 2 of them but then i had a inspecter make me install 2 because he said 2005 code says you have to. Well he is wrong just by telling me i have got to put 2 in the ground but he is right if he checks the soil are wants me to check the soil. Iam wondering about what you just said about adopting the 2005 code why would still not have to drive a ground rod? Also wondering if anybody has heard of no keyless fixtures in manhole anymore, I was made to change it out he said it was comeing out in 2007 but i did not think he could inforce what has not come out yet, yet alone inforce what him and his buddys are sitting around talking about. He has also told me that comeing in 2007 (but is inforceing right now) that when you jump the regulater on a hot water heater not only do you have to go to the cold water pipe but also the hot water.

Speedy Petey

First off. There is NO 2007 NEC. Could it be they are referring to a local ammendment?

The supplemental electrode, and also the 25 ohm rule, are NOT new 2005 additions. They have been in as long as I have known.

The 25 ohm requirement has been a bone of contention for me. The code says we must meet this level of resistance. It does not say who is responsible for determining it. Most disagree with me that I think it is the authority's responsibility to check it. They say we either need to check it with a $1000 tester or simply sink two rods. I now choose the latter.

In 2005 they changed the wording for electrodes in 250.50 from "If available..." to say all electrodes "that are present at each building or structure served shall be bonded together to form the grounding electrode system." The rebard used in footings is a concrete encase electrode (CEE, or Ufer), and MUST be used. This Ufer is also the supplemental electrode to a water pipe. It also does NOT have to meet the 25 ohm requirement a rod, pipe or plate does.

Here is the Handbook commentary on this:

Section 250.50 introduces the important concept of a ``grounding electrode system,'' in which all electrodes are bonded together, as illustrated in Exhibit 250.21. Rather than total reliance on a single grounding electrode to perform its function over the life of the electrical installation, the NEC encourages the formation of a system of electrodes ``that are present at each building or structure served.'' There is no doubt that building a system of electrodes adds a level of reliability and helps ensure system performance over a long period of time.
This section was revised for the 2005 Code to clearly require the inclusion of a concrete-encased electrode, described in 250.52(A)(3), in the grounding electrode system for buildings or structures having a concrete footing or foundation with not less than 20 ft of surface area in direct contact with the earth. This requirement applies to all buildings and structures with a foundation and/or footing having 20 ft or more of 1/ 2 in. or greater electrically conductive reinforcing steel or 20 ft or more of bare copper not smaller than 4 AWG. However, an exception does exempt existing buildings and structures where access to the concrete-encased electrode would involve some type of demolition or similar activity that would disturb the existing construction. Because the installation of the footings and foundation is one of the first elements of a construction project and in most cases has long been completed by the time the electric service is installed, this revised text necessitates an awareness and coordinated effort on the part of designers and the construction trades in making sure that the concrete-encased electrode is incorporated into the grounding electrode system.

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