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|06-13-2007, 05:02 PM||#1|
Join Date: Jun 2007
Posts: 3Rewards Points: 10
I was wondering if someone could answer these questions for me. In the past when doing a service upgrade, if the existing wires were too short, we were allowed to pig tail an extention wire with a wire nut and this was considered okay. I have been out of the field for some time but have done it on my own service upgrade a few years ago and passed. I am now building a new house for myself, after a brief talk with a local inspector, he said that a seperate box must be installed and new wires must be installed from this box to the new panel. He said that extentions in the panel will not pass. Is this how the code reads in the NEC. He also said that it is required on the panel ground to the water pipe be a continueous piece of wire clamped before the meter and clamped after the meter. I thought that this could damage the meter which in my area have electronic readers built in. Would it not be better to bring the the wire and clamp it after the meter, then use a seperate jump wire around the meter. Just for my own personal knowlege. Thanks.
|06-13-2007, 05:45 PM||#2|
Licensed Electrical Cont.
Join Date: Feb 2004
Location: NY State
Posts: 7,007Rewards Points: 366
On the first point he is flat wrong. There is NO prohibition of splicing "pigtails" in the panel. The blanket "No splices in a panel" idea is a long perpetuated MYTH.
The second point is less clear. A GEC must be continuous, and it is required that the GEC be jumpered around tings like water meters, but there is no express writing that the jumper be continuous with the GEC.
It is simply assumed that the conductor be continuous. It is simply easier that we as well. There is no good reason to use a separate piece since you are so close to the meter.
250.52 Grounding Electrodes
(A) Electrodes Permitted for Grounding
(1) Metal Underground Water Pipe A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.
250.53(D) Metal Underground Water Pipe Where used as a grounding electrode, metal underground water pipe shall meet the requirements of 250.53(D)(1) and (D)(2).
(1) Continuity Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.
250.64 Grounding Electrode Conductor Installation
(C) Continuous Grounding electrode conductor(s) shall be installed in one continuous length without a splice or joint except as permitted in (1) through (4):
(1) Splicing shall be permitted only by irreversible compression-type connectors listed as grounding and bonding equipment or by the exothermic welding process.
(2) Sections of busbars shall be permitted to be connected together to form a grounding electrode conductor.
(3) Bonding jumper(s) from grounding electrode(s) and grounding electrode conductor(s) shall be permitted to be connected to an aluminum or copper busbar not less than 6 mm × 50 mm ( 1/ 4 in. × 2 in.). The busbar shall be securely fastened and shall be installed in an accessible location. Connections shall be made by a listed connector or by the exothermic welding process.
(4) Where aluminum busbars are used, the installation shall comply with 250.64(A).
250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes
(B) Effective Grounding Path The connection of a grounding electrode conductor or bonding jumper to a grounding electrode shall be made in a manner that will ensure a permanent and effective grounding path. Where necessary to ensure the grounding path for a metal piping system used as a grounding electrode, effective bonding shall be provided around insulated joints and around any equipment likely to be disconnected for repairs or replacement. Bonding conductors shall be of sufficient length to permit removal of such equipment while retaining the integrity of the bond.
Examples of equipment likely to be disconnected for repairs or replacement are water meters and water filter systems.
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.
Answers based on the 2008 & 2011 NEC.
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