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Randall Clark
04-10-2011, 07:20 PM
In looking at older homes with copper distribution pipes, anyone know what year they started bonding to the electrical system?

Tom Thompson
04-10-2011, 09:14 PM
In looking at older homes with copper distribution pipes, anyone know what year they started bonding to the electrical system?

In what local (city/ state)are you inquiring for?

Frank Norman
04-10-2011, 11:27 PM
In this area, in older houses with copper water piping and grounded electrical circuits, the copper supply pipe provided the grounding, i.e. was the grounding conductor rather than being bonded to a grounding conductor. So is the question in what year were grounded circuits first required? Perhaps Randall could elaborate a little on the situation. Is it about a house that has grounding provided by ground rods, and the copper water pipes are not bonded to the ground? Even in older houses with ungrounded Knob and Tube supplied outlets and lighting circuits, there is usually at least one grounded circuit for something, and the ground in these places is typically provided by the water pipe alone.

More recently, the 1975 BC code for example said that that if a metallic water pipe enters the building this must be used as the ground, unless it's short, in which case a supplementary ground rod is required. Later this became two supplementary rods. Now the ground basically can be any buried conductor with an exposed bare metal area of at least 462 square inches. All metallic piping inside the building, such as gas, water, and drain piping, that is not part of the piping used for a ground electrode must be bonded to the ground.

Randall Clark
04-11-2011, 05:22 AM
House was built in 1973 in Raleigh, NC. It has a GCE rod in the yard but also has copper pipes (from the meter and on through home). I could not find a ground or bond wire attached to the copper pipe.

Norman Ellis
04-11-2011, 06:00 AM
In this area, in older houses with copper water piping and grounded electrical circuits, the copper supply pipe provided the grounding, i.e. was the grounding conductor rather than being bonded to a grounding conductor. So is the question in what year were grounded circuits first required? Perhaps Randall could elaborate a little on the situation. Is it about a house that has grounding provided by ground rods, and the copper water pipes are not bonded to the ground? Even in older houses with ungrounded Knob and Tube supplied outlets and lighting circuits, there is usually at least one grounded circuit for something, and the ground in these places is typically provided by the water pipe alone.

More recently, the 1975 BC code for example said that that if a metallic water pipe enters the building this must be used as the ground, unless it's short, in which case a supplementary ground rod is required. Later this became two supplementary rods. Now the ground basically can be any buried conductor with an exposed bare metal area of at least 462 square inches. All metallic piping inside the building, such as gas, water, and drain piping, that is not part of the piping used for a ground electrode must be bonded to the ground.


In what local (city/ state)are you inquiring for?

Asking what city or state covers the time frame to the question. But! Lets get a better understanding of the ground electrode conductor.

Before we had grounded circuits such as knob and tubing or even the first couple decades of romex, grounding was just being brought into new construction.

Frank mentioned water bond! being used for the ground electrode conductor, when adding grounded circuits to an older service it was required to provide ground, this was the closest and least invasive way to provide grounding protection. but alot of main water lines did not have the contact to earth required by code yet accepted.

Deeper explanation. electrical charge/surge displacement.
Pending electrical charge displacement, the electrode conductor requires a large area of earth or it can stay in the structure, causing damage to the electrical service or other conductive materials.

Coflict with installing a ground system on older electrical services would begin with the routing of existing circuits, what is exposed, open air junctions in wall cavities, deterioration factor on the wiring and electrical equipment, and more that can make contact with conductive materials of the structure if the electrical charge does not deteriorate or be sorbed to the earth from lack of electricity to earth displacement.

When older homes where built alterate energy was used for heat or light, alot of time due to cost materials would be left in the structure when these homes had an electrical service installed, and those items could very well become charged if a large electrical charge or surge was to occur.

electrical fires are the dealiest type of residential fires by average, and we have 38 electrical fires an hour in the residential region of our country, so wanting to know about bond and grounding is very important and needs to be understood better by inspectors.

kevin hergert
04-11-2011, 09:57 AM
I have seen this condition many times. Galvanized pipes are abandoned (cut) and new copper installed. There is no modification to the ground or bonding. It is now connected to a disconnected galvanized pipe (the wire does not touch the new copper pipe). The galvanized pipe is cut just above the floor insulation and just outside the foundation

Jerry Peck
04-11-2011, 05:03 PM
anyone know what year they started bonding to the electrical system?

In the 1962 NEC.

Randall Clark
04-11-2011, 05:45 PM
Thank you all for the information.

dana1028
04-20-2011, 01:13 PM
In looking at older homes with copper distribution pipes, anyone know what year they started bonding to the electrical system?

Are you referring to the grounding electrode system [today's NEC 250.50] or to the internal bonding requirements [today's 250.104].

dana1028
04-20-2011, 01:23 PM
In 1971 a new code section [250-80] was added to the code:
'Bonding of Piping Systems' - All interior metallic water and gas piping which may become energized shall be bonded together....

I don't know if this requirement can be found elsewhere in the code for earlier years. That said, this 'new' requirement would prob. not have been adopted into state/local codes for 1-3 yrs. after this code cycle.

dana1028
04-20-2011, 01:24 PM
In the 1962 NEC.

Jerry - is this the electrode system or the interior water piping system? Could you please provide a code section. thanx

Jerry Peck
04-20-2011, 03:41 PM
In the 1962 NEC.


In 1971 a new code section [250-80] was added to the code:
'Bonding of Piping Systems' - All interior metallic water and gas piping which may become energized shall be bonded together....

I don't know if this requirement can be found elsewhere in the code for earlier years. That said, this 'new' requirement would prob. not have been adopted into state/local codes for 1-3 yrs. after this code cycle.

It can, that is where I got it from, and the first time that appeared was in the 1962 NEC.


Jerry - is this the electrode system or the interior water piping system? Could you please provide a code section. thanx

You mean I have to go look it back up?

Okay.

Jerry Peck
04-20-2011, 04:15 PM
Jerry - is this the electrode system or the interior water piping system? Could you please provide a code section. thanx

Dana,

No problem in looking it back up.

The first answer is "both".

The second answer is 250.81.

The 1962 NEC, in 250.81, starts out being about metallic underground water piping as a grounding electrode and finishes up being about metallic interior water piping systems being grounded, then electrically continuous, then of bonding gas, sewer, hot water piping and metallic air ducts within the premises.

The code had not yet figured out all the nuances and wording that was to become tweaked and updated in the many editions which followed since that 1962 edition.

John Kogel
04-21-2011, 08:43 AM
electrical fires are the deadliest type of residential fires by average, and we have 38 electrical fires an hour in the residential region of our country, so wanting to know about bond and grounding is very important and needs to be understood better by inspectors.


I have seen this condition many times. Galvanized pipes are abandoned (cut) and new copper installed. There is no modification to the ground or bonding. It is now connected to a disconnected galvanized pipe (the wire does not touch the new copper pipe). The galvanized pipe is cut just above the floor insulation and just outside the foundationI would like to add that we should not be too concerned as to whether the code called for grounding or bonding at the time of construction, but rather, is the home wiring safely grounded, and are the water pipes safely bonded now?

Since we as HI's can't determine the quality of the grounding, we need to be on the alert for possible defects, such as the cut pipes in Kevin's crawlspace, and call for an electrician to confirm the connections are properly made. Regardless of the age of the wiring.

Norman Ellis
04-21-2011, 11:11 AM
Additional concerns passed off, blanked off electrical boxes, receptacles set at different levels in a room. different types of NMSC (Non metalic sheathed cable/romex) in the home not labeled to breakers. over 20% of electrical house fires are caused by defective remodel, addition and repair work.
if you would like more information on this research visit New World Electrical Consultants & home inspections (http://www.safehomeenergy.com)



I would like to add that we should not be too concerned as to whether the code called for grounding or bonding at the time of construction, but rather, is the home wiring safely grounded, and are the water pipes safely bonded now?

Since we as HI's can't determine the quality of the grounding, we need to be on the alert for possible defects, such as the cut pipes in Kevin's crawlspace, and call for an electrician to confirm the connections are properly made. Regardless of the age of the wiring.

Ted Menelly
04-21-2011, 02:04 PM
No ground rod in older homes I write it up. No pipe bonding in older homes I write it up. A lightening strike (or what ever) to the home with improper grounding or bonding and , well, we all know the what could happens.

There is no good reason or logical reason not to write up either, no matter what any old code was.

Norman Ellis
04-21-2011, 02:41 PM
GFCI (Ground Fault Circuit Interupter) as home inspectors we look for these devices in garages, exterior areas, basements, and within 6' of running water. Homes built before these device came to the market did not require them, and we went over 2 decades before they became mendintory to be installed in exsisting homes (nation wide). But what people even inspectors don't understand is the wiring installed at the time these homes where built is more than likely in need of replacement. so I recommend having the circuits tested/evaluated before any alterations are done to any circuit that old. Because homes built in the 50's early 60's even the 70's might not be a grounded circuit. Gounding began in the early 60's but we still to date have areas not under state inspectors and the grounding could be installed wrong.


No ground rod in older homes I write it up. No pipe bonding in older homes I write it up. A lightening strike (or what ever) to the home with improper grounding or bonding and , well, we all know the what could happens.

There is no good reason or logical reason not to write up either, no matter what any old code was.

Glenn Mann
04-29-2011, 01:53 PM
House was built in 1973 in Raleigh, NC. It has a GCE rod in the yard but also has copper pipes (from the meter and on through home). I could not find a ground or bond wire attached to the copper pipe.


Randall, it depends on the Code set adopted by the AHJ at the time the service was installed. However, we do have an NEC history reaching back to at least 1968. The 1968 NEC, Part H, Section 250-81, entitled, Water Pipe, states in part, "A meallic underground water piping system, either local or supplying a comunity, shall always be used as the grounding electrode where such a pping system is available."


Section 250-83, entitled, Made Electrodes, of the 1968 NEC states, in part, "Where electrodes described in Sections 250-81 and 250-82 are not available, the grounding electrode shall consist of a driven pape, driven rod, buried plate or other device approved for the purpose and conforming to the following requirements."

Glenn Mann
04-29-2011, 02:01 PM
House was built in 1973 in Raleigh, NC. It has a GCE rod in the yard but also has copper pipes (from the meter and on through home). I could not find a ground or bond wire attached to the copper pipe.


Randall, it depends on the Code set adopted by the AHJ at the time the service was installed. However, we do have an NEC history reaching back to at least 1968. The 1968 NEC, Part H, Section 250-81, entitled, Water Pipe, states in part, "A metallic underground water piping system, either local or supplying a community, shall always be used as the grounding electrode where such a piping system is available."


Section 250-83, entitled, Made Electrodes, of the 1968 NEC states, in part, "Where electrodes described in Sections 250-81 and 250-82 are not available, the grounding electrode shall consist of a driven pipe, driven rod, buried plate or other device approved for the purpose..."