When were driven ground rods required by code?

[smallfish]

Here in a suburb of Detroit, copper and iron plumbing pipe is being replaced by plastic. Older residential service panels were grounded by connection with ground clamp to the nearest cold water pipe with #6 or #8 copper wire. There was no evidence of a driven ground rod. Building Rehabilation Codes often require "one for one" or replacement with the same. This would require a system ground connection to the metal underground water pipe only.
When does the code require a connection to newly driven ground rods per current code?
When was it that ground rods were required for residential services?
Knowing this date, it would be apparent if the service was installed in violation and therefore in need of driven rods in addition to waterpipe.
Thanks

 

[Dennis Alwon]

The code now and for many years- not sure when- has required a supplemental ground. Thus if there was a metal water pipe you had to run the grounding electrode conductor to that but you still had to either drive 2 rods or use any of the other approved means such as a concrete encased electrode (ufer) etc. Again I am not sure when this came to pass.

The reason the rods (most common means) are required to supplement the water pipes is for the reason you are experiencing where the water lines get changed to plastic. If the water line is still metallic coming into the building you still need to connect to it even if the plumbing in the building is all plastic

 

[mjf]

When it comes to "rehab", replacement, or upgrading of residential service equipment your local POCO may have grounding requirements above and beyond your local Building Rehabilitation Codes.

 

[infinity]

The 1975 NEC did not require a supplemental electrode for a 10' or longer metal water pipe.

 

[jumper]

The 1978 NEC is when a water pipe electrode was required to be supplemented with additional electrodes.

Here is a similar thread:

http://forums.mikeholt.com/showthread.php?t=135832

 

[kwired]

I was going to say it wasn't until late 60's or into 70's before non metallic water entrances were becoming common, so I doubt it was anytime before that that they required supplemental grounding if the reason was because of potential replacement of the water line with nonmetallic piping. IIRC it was about 1993 or 1996 when they finally decided the water pipe GEC must attach within 5 feet of entry into the structure of the water pipe. Before that you could hit the water piping at any convenient place as long as it was continuous metal to the underground portion or if you installed bonding jumpers to make a continuous path.

 

[cmreschke]

I would just drive the rod if there isn't one there. No point trying to find out if it was required at the time it was installed.
Outa curiosity what suburb? I'm 50 miles north of Detroit.

 

[jxofaltrds]

If this service was approved it is in violation of nothing.

Now as others suggested lets talk about today and what you should do.

New in 2011 NEC

250.53 Grounding Electrode System Installation.
(2) Supplemental Electrode Required. A single rod, pipe,
or plate electrode shall be supplemented by an additional
electrode of a type specified in 250.52(A)(2) through
(A)(8). The supplemental electrode shall be permitted to be
bonded to one of the following:
(1) Rod, pipe, or plate electrode
(2) Grounding electrode conductor
(3) Grounded service-entrance conductor
(4) Nonflexible grounded service raceway
(5) Any grounded service enclosure
Exception: If a single rod, pipe, or plate grounding electrode
has a resistance to earth of 25 ohms or less, the
supplemental electrode shall not be required.
(3) Supplemental Electrode. If multiple rod, pipe, or plate
electrodes are installed to meet the requirements of this
section, they shall not be less than 1.8 m (6 ft) apart.

Please read all of 250.53

 

[knightstar]

Distance from Service entrance to the grounding electrode

Distance from Service entrance to the grounding electrode

The 1978 NEC is when a water pipe electrode was required to be supplemented with additional electrodes.

Here is a similar thread:

http://forums.mikeholt.com/showthread.php?t=135832

My Question is: In a single family residence: What is the maximum distance from the Service entrance panel, with out any previous disconnects, can the main grounding electrode be installed.

 

[kwired]

My Question is: In a single family residence: What is the maximum distance from the Service entrance panel, with out any previous disconnects, can the main grounding electrode be installed.

As close as is practical is generally a good design choice, but NEC does not specify any distance, and that is for made electrodes, other existing electrodes (water pipe, CEE, structural metal) are where they are.

 

[mwm1752]

Here in a suburb of Detroit, copper and iron plumbing pipe is being replaced by plastic. Older residential service panels were grounded by connection with ground clamp to the nearest cold water pipe with #6 or #8 copper wire. There was no evidence of a driven ground rod. Building Rehabilation Codes often require "one for one" or replacement with the same. This would require a system ground connection to the metal underground water pipe only.
When does the code require a connection to newly driven ground rods per current code?
New installations require a min of 2 if there are no other availiable electrodes & the 25 ohms resistance required for a single rod is not met. or 1 is required as a supplement to specified electrodes in the code if there is no other choices.
When was it that ground rods were required for residential services?
My 1956 NEC has ground rods as an acceptable electrode method and still required at least 2 made electrodes for the system if 25 ohms resistance was not met. The requirement for the rods was a choice by the installer to use over another made electrode that could be used.
Knowing this date, it would be apparent if the service was installed in violation and therefore in need of driven rods in addition to waterpipe.
The violation would be if the electrode system did not have a 25 ohm resistance or at least 2 electrode tied to it.

 

[al hildenbrand]

My 1956 NEC has ground rods as an acceptable electrode method and still required at least 2 made electrodes for the system if 25 ohms resistance was not met. The requirement for the rods was a choice by the installer to use over another made electrode that could be used.

Yes, that is true. The NEC has a long history of describing how to use a "made" grounding electrode. However, in the context of the opening post, the requirement for a ground rod to supplement a metallic water service, where the metallic water service meets the NEC requirement as a grounding electrode, is the point.

As Jumper and Infinity have noted, the 1978 edition of the NEC is the first occurrence of the "supplement" requirement. The actual calendar date of enforcement of this requirement for any one structure would depend upon the local jurisdiction historical record of adoption into local ordinance as enforceable statute. . . sometime after the printing of the 1978 NEC.

 

[kwired]

Yes, that is true. The NEC has a long history of describing how to use a "made" grounding electrode. However, in the context of the opening post, the requirement for a ground rod to supplement a metallic water service, where the metallic water service meets the NEC requirement as a grounding electrode, is the point.

As Jumper and Infinity have noted, the 1978 edition of the NEC is the first occurrence of the "supplement" requirement. The actual calendar date of enforcement of this requirement for any one structure would depend upon the local jurisdiction historical record of adoption into local ordinance as enforceable statute. . . sometime after the printing of the 1978 NEC.

OP just asks when driven ground rods were required, and I never took it to be asking when a supplemental electrode was required, but maybe that was what OP was after.

As far as supplemental grounding for a water pipe, it does not have to be a rod it can be any other electrode recognized by 250.52