Inspector's Bad Ground Call
Inspector's Bad Ground Call
(OP)
I had to move the power pole for my shop about 10' as my old ground 3/8" EC Copper 16 ft long is going to be covered up. I installed a new ground made from EC Copper 3/4" rod with 1/4" bore x 20' long and hooked every thing up. It was inspected yesterday and when I went out to get the number off the inspection ticket for the power company the ground was noted as not up to code and had not passed inspection no other explanation.
It is a only a 100 Amp Main and the local codes say 3/8" copper or 1/2" copper plated steel ground rod.
What could be the reason for the inspectors call?
It is a only a 100 Amp Main and the local codes say 3/8" copper or 1/2" copper plated steel ground rod.
What could be the reason for the inspectors call?






RE: Inspector's Bad Ground Call
Pls more information about your install;
1/ pls tell me what "EC" stands for here.
2/Where is the main service disconnect in relation to the pole and gnd rod? Is the main service disconnect on the pole?
3/ The gnd is "driven" in at the pole or is it layed in the gnd?
4/ Where are you located?
5/ Are u using approved bonding connectors? Are they brass or brass/copper type connectors. Does the conductor to the gnd rod in your area need to be looped?
The inspector may not have liked the gnd rod location. The local inspection authority may require your rod to be closer to the main service disconnect. For example, if you have a meter on the pole are you mistakenly bonding the "common" or "wht" wire in the meter base to your gnd rod at the pole? Most inspection authoritys require you to bond the white wire to your gnd rod at the main service disconnect and this gnd rod will be as close to the main service disconnect as possible. Well it does in Ontario but it may be different where u are.
Please elaborate.
RE: Inspector's Bad Ground Call
The main service disconnect is on the pole at present. It is 5' off the ground and right above the ground rod. The grounding wire is about 3/32 dia bare Copper.
The ground rod point was driven into wet sand with about 1' sticking out. It is located about 6" from the pole.
In North West Florida.
All the wiring connections you mention are correct and using approved connectors.
From what I read into the rejection notice he is objecting to the ground rod itself.
Could it be that the rod is not solid? I have more area than any requirement that I'm aware of.
RE: Inspector's Bad Ground Call
Please, notice that NFPA 70-2002 NEC does not cover grounding rods (electrodes) themselves. It only covers connections to them.
Products are not covered by NEC, they are covered or complying with industry standards.
The older NEC e.g. 1996 has the following requirements that may have been violated:
Article 250-83 Made and Other Electrodes.
(c) Rod and Pipe Electrodes.
(3) ...The upper end of the electrode shall be flush with or bellow ground level unless the aboveground end and the grounding electrode conductor attachment are protected against physical damage as specified in Section 250-117.
RE: Inspector's Bad Ground Call
There are NRTL-labeled copperweld-like rods. Maybe that was what he was looking for? I think some consider the UL stamp near its top as evidence that the rod was not sawed off.
Might he buy into a <25O fall-of-potential [3-lead ground-resistance] test as reasoanble proof it will do the job?
RE: Inspector's Bad Ground Call
(G) Rod and Pipe Electrodes, regarding the electrode flush
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
I generally find Inspectors are the least educated in the Electrical Trade. So many end up as "Cliff Claven" types who a appear as "knowledge gods" to even less educated Electricians. And when you question them they almost always manage to find a defect with your installation. So what I do is create a defect for the inspector to find so that he can "teach" me about the evils of the defect I created. My installlations are always up to code but I have one inspector who always finds some trivial unimportant little thing to hold up the installation. Not that they won't turn the power on but just that they want some defect corrected.
I have even gone to the Inspector's supervisor to have a "defect" ruling overturned. I disagreed with his call so I protested it and won.
I know I will offend people here but I run into these types of Inspector's al the time. Maybe your's is just like this.
RE: Inspector's Bad Ground Call
I think they often zero in on grounding because it looks familiar and they feel they are on safe ground (so to speak).
I generally try to accommodate minor changes, even if I don't agree with the necessity just to keep a good relationship. It always good to leave the other person a way out with dignity that allows them to save face. You tend to run into the same people again in this business.
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
Both the cable company and telephone company have hooked their grounds to the ground wire from the box to the ground rod. I ask the telephone guy did he see anything wrong with the ground and he said that everything checks out. The box still has the sticker that was put on 5 years ago, nothing has changed except I do have a larger ground wire and new larger ground rod and clamp.
I drove the rod deeper to almost level with the ground as suggested and cleaned the ground clamps, had a patina from storage, and changed the screws in the clamp. The distance to concrete is 11", no way nothing could get in and damage the ground wire or rod.
I tried to get a quote from an reputable electrical contractor to put his sticker on the box. His answer was $1750 to set a new pole and box. He would use a treated pole 6".25# CCA and mine is a 9" .8# CCA pole. My box is a GE with GE breakers he couldn't tell me who’s box he would use. Will not check my setup out. I asked about doing a test of the ground as mentioned in the posts and his answer was that the test was a waste of his time and my money.
I was very nice and ask for another inspection and if I could get an explanation of the problem. The answer was short and sweet, we are not in the contracting business and we will get back to you as time permits. I am getting the idea that they don't like me doing the work. I was very nice and do have one thing going for me as it's an election year.
All this and I used to be charge of over inspectors for a large chemical company.
Thanks very much for everyone’s help and suggestions. I will post the results of the next inspection and if I am here maybe I’ll get an explanation.
Will coffee and donuts or maybe lunch help.
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
Did you follow the 2002 NEC.
An outside pole should not be a problem.
But you only noted that you drove ONE ground rod the NEC requires there be 2 if you can not prove that you have the minimum resistance of 25 ohms to ground.
If you drive two then you will be covered and will not have to prove the " 25 ohms " to ground. (I have no idea where this number comes from)
Another thing to check is to make sure that the 'main bonding jumper is properly installed.
Another thing is the rod should be at least flush with the
surface of the earth if not it is to be protected.
Finally the connectors are supposed to be 'listed' for direct burial'.
For a 100 amp service No. 8 copper is to be used as the grounding electrode conductor. but must be protected, ie in conduit if in metal conduit that is ridgid it also must be bonded at both ends, so use PVC.
Easier is to use No. 6 bare stranded and then you avoid the protection clause and it can follow the contour ot the pole into the ground. The No. 6 can be strapped right to the pole.
Good luck
WOC
RE: Inspector's Bad Ground Call
Pls tell me. Just how are you measuring the gnd resistance value - between what 2 points? And what device are u using to measure this resistance value?
Been in the trade for a long time and I haven't got a clear answer for these questions yet! Can u answer me?
Shouldn't the gnd "resistance" between any 2 points in your "properly gnded, properly bonded elctrical system" be so small as be unmeasurable?Oris this mysterious 25ohm value the maximum "resistivity" of the earth between any 2 points measured "thru the earth"? Huh.? And just how do you measure this without 2 or more gnd stakes and performing tests on the earth without a"zero balancing" meter such as a "Miller" meter.
Pleasedon't say "ohms to gnd". You are confusing me!
RE: Inspector's Bad Ground Call
See Understanding Ground Resistance Testing at http://www.aemc.com/techinfo/techworkbooks/ground_resistance_testers/950-WKBK-GROUND.pdf
RE: Inspector's Bad Ground Call
IEEE Std 80-2000 IEEE Guide for Safety in AC Substation Grounding.
Section: 19.1 Measurements of Grounding System Impedance
for methods:
19.1.1. Two-point method
19.1.2. Three-point method
19.1.3. Ratio method
19.1.4. Staged-fault test
19.1.5. Fall-of-potential method
RE: Inspector's Bad Ground Call
The 25 Ohm value noted in the NEC applies to the maximum resistance for a single made electrode. If a higher resistance is obtained for a single electrode, a second(paralleled) electrode is required. This should NOT be interpreted to mean that 25 ohms is a satisfactory level for a grounding system.
The wording in the NEC comes down to show me 25 ohms to ground or drive two ground rods.
For a Single phase residential/small commercial of 100 amps as listed above I have never heard of anyone checking the resistance to ground. It can be done, they make a real neat clamp-on tester that is accurate and also fairly expensive.
The requirement of two ground rods that are only 5/8 dia. and 8 feet long is not going to achieve any reuslts better than maybe 15 to 20 ohms to ground.
These ground rods were never intended to trip a breaker or blow a fuse, In the NEC it clearly says that the grounding electrode shall NOT be used as the sole equipment grounding conductor but shall be tied to the Neutral bus to tie the system together.
Also that a grounded system conductor shall be run to each service.
WOC
RE: Inspector's Bad Ground Call
I'm in possession of a electric inspection sticker for the electric service to my shop.
To my great surprise the electrial inspector, the writing looks the same as on the denial paper, came this morning while I was in the process of checking my new ground using power from a heavy duty extension cord, with its' GFI out of the circuit, and using 3 different GF1 devices. He witnessed one test on a very sensitive GFI used by an inspection company that I had borrowed. I informed him that everything that I had tested in the shop to the new ground had tripped a GFI. He made no mention of the previous problem with the ground, in fact he didn't open his notebook on site. I didn't ask as about the previous ground problem, though I should have to give everyone who responded an answer as to why the refusal on the first inspection.
All he did was check the tightness of the treminals in the power panel and the panel inside and put a sticker on the box and said I could call the power company. Until I get power I can use my shop using the extension cord and before everyone gets on me it’s is #9 stranded wire with all the appropriate safe guards.
Again thanks to everyone who responded to my inquiry. I might try to find out what was wrong on the first try once I have power.
jbartos,
The only thing different this time was the ground rod was driven flush with ground as you first suggested.
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
RE: Inspector's Bad Ground Call
The problem now is that I know more than I want to know. From all the information presented I have concluded that a gnd rod or gnding arrangement installation is generally a "gamble". Albeit, an educated gamble. The gamble being that you have a low gnd electrode resistance or not. Who does soil resistivity tests? I haven't as an Electrician. I did as a Corrosion Tech though and I would have remembered seeing an Electrician measuring soil resistivity in the past. So who is ensuring safe gnds and what constitutes a safe gnd? And when these tests are performed is it in a wet or dry season?
What I am thinking is that depending on the soil resistivity and other variations in your area there may be times of the year where you have a very high gnd electrode resistance and little protection against lightning strikes.You may as well pull all the gnd conductors off the gnding electrode during that time of year. It is also important to note that the resistance in copper gnd bond conductors - that protect you against shock from equipment not lightning strikes - does not change with the seasons. The main and most obvious reason for gnding a system to earth is to offer a path for lightning strikes. Obviously personel safety is improved over a ungnded system but I won't get to the details.
How often does your GND electrode clear a lightning strike. Maybe never. How often does a good bnd in a properly gnded system protect a person from shock. Almost always. So the fact that you have all your gnd bonding conductors to a gnd electrode (one point) is good. Whether the gnd electrode has low resistance to earth is another question and is of very little consequence 99% of the time. The conclusion I have come to is that a properly gnded system requires a GND electrode and proper gnd bonding of equipment.However, gnd bonding is more important for personel safety.
GND ELECTRODE - needed, important
GND BONDING - Absolutely essential, more important than gnd electrode.
So the next time you see someone driving a gnd rod next to a machine in a factory somewhere tell them they are wasting their time. Save someone's life. Who knows maybe they will be the first electrocuted but probably some poor smuck operating the equipment will.
RE: Inspector's Bad Ground Call