To ground or not to ground...

Yes, often homeowners will take more time and care to do an above average job. I'm glad you resolved your problem *and* had it properly inspected. Now you *know* the job is done right :-)

daestrom

Hey I got it right, I had figured it out when Mr. Tarin told me he had main breakers on his panel, i asked him to run that by the inspector again with the specific detail, in fact it was not a subpanel as mentioned.

can anyone explain the extra 2 volts measured at the cabin?

AND: That's a wrap ....

=AEoy

The line voltage varies over time. A 2 volt difference (1%)is trivial. I would assume when the cabin registered 246 volts the meter was at a higher voltage. Bud--

tarin wrote: > Question: He measured the voltage potential at the meter and it registered

You should always use a totally separate earth grounding system on a sub-mains supply. A separated out-building should always have its own local earth fault conductor, and should never rely on the transfer of an earth fault loop directly from the supply source. The wiring for the sub-mains supply to the out-building should be protected by the main earth, but once at the out-building the distribution apparatus should have also have its own local earth grounding spike installed, and a heavy gauge conductor connected between the distribution panel and the spike of course.

"Takoma Park Volunteer Fire Department Postmaster" wrote in message news:Br01e.9751$uw6.4922@trnddc06... Roy Q.T. wrote: Mr. Tom H I already Stated the code that Prohibits Grounding the Neutral at a Subpanel of a System that is already Neutral/Grounded at the Service Disconnect, Yet you insist in Harassing Mr. Tarin & Other here into believing your way is the Only correct way. FURTHERMORE: You are even Challenging the Code Inspectors Decision (Not Good Form Fellow) as if your concern for Life is some how Greater than His that is His Job in his specific Field to Prevent the Lose of Life and Oversee Electrical Ethics. Other than charge you as a Nuisance: With All Due Respect To Many Cases of Death By Electrocution you've seen in your Career., I, in my 28 years in the Field Have Not Caused Ever a single Shock Much Less the displeasure of Witnessing a Death so Horrific, as it apparently is Custom with your Fellow WorkClass Men., Nor Have any of The Men from my Training Academia Ever Suffered a Single Death due to Improper Handling or Design of an Electrical System. If your Workmanship is anything close to the poor writing skills I've noted in you here today and that you've so Egregiously Displayed here., You should only Be Concerned about Yourself and Seek Professional Help & Counselling. Your Replies are Alarming and Unfounded., only of your Lack, of Ethics Towards Others & Security in your Profession. Sincerely: Roy Q.T Roy The code does not forbid the bonding of the neutral to ground on the load side of the Service Disconnecting Means in all cases. There are several specific exceptions and buildings supplied from a service located elsewhere is one of them. Characterizing my response to another posters questions as harassment is an interesting bit of hyperbole. As for challenging a code official I have done it several times. The vast majority of the electrical inspectors I have dealt with have been consummate professionals. When I encounter one that is not knowledgeable or who substitutes personal preference for adopted code I do call them on it. Appointment as a code enforcement official does not make anyone infallible. In the course of thirty five years in electrical work I have had a few inspectors insist on things like: plastic boxes in runs of metallic cable or raceway without any bonding means in the boxes, the installation of a service rated fused switch ahead of a fire pump controller that was listed as "suitable for use as service equipment", the installation of a main breaker in a twelve slot panel being used as service equipment with five double pole breakers installed on the grounds that two single pole breakers could be installed that would raise the number of breakers to more than the permitted maximum of six, and several more. Inspectors are just human beings who are doing very important work. They can make mistakes just like anybody else. I would much prefer being a nuisance than siting idly by while unqualified advice is given that will endanger the person receiving it. I cannot see how I should be embarrassed in any way by having seen a number of electrical injuries and deaths in the course of over thirty years of service as a volunteer fire fighter / rescuer. Am I supposed to be ashamed that I crawl into the buildings that most folks run out of? If you are going to criticism another fellows writing it would behoove you to make sure that your criticism is written intelligibly. That last bit isn't even a complete sentence.

you know i still don't like it. neutral and ground together }:-o on the same electrode ? ~>

That may have balanced out any charge developed from the pole, but will it conduct safely to earth if the charge on the neutral has somehow made the potential higher on the ground fault system? where stands the bonding point for a regular outlet/appliance/tool?

This neutral bonded system assumes the ground potential at the user levels will never be less than the combined neutral/earth ground resistance.

for safeties sake: I don't by it !

=AEoy

What's a guy with 6+ years University education doing running around with tools? Plus the time it takes to get a journeyman's licence..

Bill

That may have balanced out any charge developed from the pole, but will it conduct safely to earth if the charge on the neutral has somehow made the potential higher on the ground fault system? where stands the bonding point for a regular outlet/appliance/tool?

This neutral bonded system assumes the ground potential at the user levels will never be less than the combined neutral/earth ground resistance.

for safeties sake: I don't by it !

®oy

Would you like to expand on the "somehow" for me please ?? What would be your preference for an alternative system ??

-- Regards ..... Rheilly Phoull

Not me, my man. I only agreed with you. As for demeaning anyone, well, I always err on the side of safety, and if that means telling someone they're totally wrong about an installation, then I tell them.

Roy Maybe it will help you understand were I'm coming from if you do the calculation of the voltage between the Equipment Grounding Conductors (EGCs) in the cabin and the earth in the event of a fault between the ungrounded current carrying conductor (hot) and one of the EGCs in the cabin. The reason it is common practice to install two ground rods is that unless the first rod has a resistance to ground of 25 ohms or less a second rod is required. Since the equipment used to measure resistance to ground is expensive and, in some cases time consuming to set up, most electricians just drive the second rod. It is very commonly true that even with two rods the resistance to ground is 50 to

100 ohms. Since the power company's multi grounded neutral is tied to ground at every transformer and at every single service disconnecting means we will assume that the resistance to ground at the transformer is effectively zero. So relative to the earth the transformer's secondary produces a voltage of 120 to ground. When that current faults to an electrode system that is not effectively bonded to the utility's Multi Grounded Neutral (MGN) the entire 120 volts is across the grounding electrode system. Since you are an electronic technician you can do the calculation in your sleep. Since V=I*R V/R=I. The voltage of 120 divided by the best case grounding electrode resistance of 25 ohms equals 4.8 amperes of current flow. The smallest Over Current Protective Device (OCPD) used in North American Practice is fifteen amperes. The impedance to ground of the isolated grounding electrode system is two high to trip the breaker and clear the fault. As long as the fault continues to exist there would be a 120 volt potential between the entire Equipment Grounding Conductor network and the earth itself. So Mr Tarin plugs in his weed-whacker, drill, or electric mower and tries to do some work either outside or while in contact with a naturally grounded surface. If the tenth of an ampere that it takes to cause ventricular fibrillation flows through his body he dies.

So instead of the isolated grounding electrode system we bond it to the grounded current carrying conductor that most of us call the neutral. The resistance of the fault clearing path now drops to less than an ohm. 120/1=120 so the OCPD opens the moment a fault occurs thus clearing the fault and provoking the occupants to repair the defect or have it repaired. By adopting this second strategy we comply with the US NEC language in 250.4 (A) (3), (4), & (5).

250.4 General Requirements for Grounding and Bonding. (A) Grounded Systems. ... (3) Bonding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. (4) Bonding of Electrically Conductive Materials and Other Equipment. Electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. (5) Effective Ground-Fault Current Path. Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a permanent, low-impedance circuit capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be used as the sole equipment grounding conductor or effective ground-fault current path.

In a three wire feeder situation the neutral is the only conductor that meets the requirements for a "permanent, low-impedance circuit capable of safely carrying the maximum ground-fault current likely to be imposed on it."

-- Tom Horne

Roy I'll take the blame for saying that you were giving out dangerous advice. Tom H

----------------- Tom Okay, if & when the EGC and everything bonded in his cabin gets electrified from neutral leakage currents, it'll be all thanks to your great advice, not mine. Roy

Perhaps 'tarin' misunderstood and the guy is a 'Master Electrician', not a a MS degree. He would be quite qualified to make the inspection and pass judgement on tarin's installation then. Actually, a MS in EE does *not*, in and of itself qualify him to make such an inspection.

daestrom

Well wonders never cease to amaze me, I got a call from a lady friend with a no lights problem, the panel was open cover on the floor, someone had done some work and disconnected and connected new stuff, he had 2 wires in a CB one of them was not secured as usual in such bad CB connections., I spliced them together & fixed the problem, But, Low & Behold I saw the Neutral Grounded to the Panel, Big as Day };-) so, there's a first for Everything & Everyone., it was a garage installation ...Thanks for putting up with me :-)

=AEoy

I'm wondering...... NEW POST ????

you can get this any other place i guess.

Best Wishes, Attentively };-) Roy Q. T.

I have a case that would answer you're concern..... it involves Terrazo Tiles on a Concrete/earth Lloor. got it? the grouding tecnique is a real puller, any equipments designed for non-isolated neutral/ground paths become totally energized., inside wall metal pipes, metal cables, metal boxes attached exposed bx or armoured metal cable wiring also, zzzzzzzzpppppp is the least to be concenred with but it can clamp down hand & leg muscles and shunt you badly....Rare Earth Ground ? =AEoy ~>

From: snipped-for-privacy@bigpong.com (Rheilly=A0Phoull) "Roy Q.T." wrote in message news: snipped-for-privacy@storefull-3256.bay.webtv.net... you know i still don't like it. neutral and ground together }:-o on the same electrode ? ~> That may have balanced out any charge developed from the pole, but will it conduct safely to earth if the charge on the neutral has somehow made the potential higher on the ground fault system? where stands the bonding point for a regular outlet/appliance/tool? This neutral bonded system assumes the ground potential at the user levels will never be less than the combined neutral/earth ground resistance. for safeties sake: I don't by it ! =AEoy Would you like to expand on the "somehow" for me please ?? What would be your preference for an alternative system ??

Most electrical panel manufactures make surge arrestors for their panels. I know SqD home line and GE do. No matter what they say the shorter the wires leading to the arrestor the better. And no increasing the wire size does not help all that much. Check to see if you manufacture makes one. Besides you need to protect 2 zones per the IEEE. So if you install one at the service and one at the point of use then you should be better protected than not installing them.

To answer that "somehow" question better, my case file wasn't clear enough i guess.

let say it's been raining and some mild lightning has charged the ground and made it less resistive then usual ground with The Neutral Not Bonded to Ground at the Service Panel any charge from the system would definetly find it's way back into the system but Being Bonded to The EGC (equipment grounding conductor) some will most surely leak to ground through the ground bonding system which is closer to the panel than the neutral path attached to it., hence i understand Why to Bond it, But It's a Fact ! No ?? !

won't there come a day with saturated earth & increased conductivity from ground that The Neutral Currents will out perform Ground Bonding and Open a Hazard to Earth or Near Earth Potential? As if Nature wasn't enough., watch out for it, Electrodes Erode.

I'm not an Electrical Wiz, not in my own opinion, but I think the Bonded Neutral at the Home level is not worth the Apparent High Current Impact Safety and is temporal at most ...... because it is logical, a current carrying neutral will eventually leak or conduct through the Earths Resistance & Ground any thing in it's path with It's Full Source Potential., and thus any metal boxes, mc cables, conduit, etc. even You.

=AEoy

any arguements are more then welcome