Wiring new shed, ground rod?

[fbelec]

Those are all 110 loads so what happened is that your AC circuit was broken intermittently since it had a good hot wire. The push pull of AC wasn't able to push and pull too well so the voltage potential varied up to 110. Shouldn't have seen any higher voltage than 110 on those circtuits. Now your 220 circuits don't even use the neutral so they should have been fine.

I have always been told that a subpanel at an outbuilding gets its own grounding system including ground rods. It will look just like a service entrance from the street where you only need three wires from the house. Hot, hot, and neutral. The ground will go to the rods.

it will see higher and lower voltages. got to see it first hand. when i got to this guys house he had 60 volts on one phase and 180 on the other. it would change with the different loads put on each phase. when i shut off his main everything was normal as far as measuring the voltage from phase to phase and from phase to ground. turn on his breaker and the voltage varied. thought it was a bad main breaker so i changed it. still the same. power company came and fixed the center tap on their wire at the pole and everything was normal. he still needs a new ground but won't here of it. so we wait for the next time it happens to him so that he can buy all new electronic.

 

[oldspark]

He needs the ground and I understand why he asked the question now, but getting off track I do not know why you need a megger for the ground rod reading, and they do not cost a 1,000, I have an old one but if I was to check the ohms on a ground rod I would just use my meter, the megger is a better tool for some things but not sure why you would use it in this case.

 

[oldspark]

Actually I looked it up and you do not use a meter or a megger, they make a special tool for checking the ground rod, the code person should be the one checking it not you, I would call him out on that.

 

[fbelec]

Actually I looked it up and you do not use a meter or a megger, they make a special tool for checking the ground rod, the code person should be the one checking it not you, I would call him out on that.

hi oldspark

can you point me in the direction of this ground rod checker. the inspectors around here want it done with a megger. i don't know why, but thats what they want. and if the fix to getting my job to pass inspection is cheap like a extra ground rod thats what i do. but now if there is ground rod checker i need to know for less work.

frank

 

[oldspark]

Actually I looked it up and you do not use a meter or a megger, they make a special tool for checking the ground rod, the code person should be the one checking it not you, I would call him out on that.

hi oldspark

can you point me in the direction of this ground rod checker. the inspectors around here want it done with a megger. i don't know why, but thats what they want. and if the fix to getting my job to pass inspection is cheap like a extra ground rod thats what i do. but now if there is ground rod checker i need to know for less work.

frank

Oh boy, can of worms, the testers are pricey and I guess there is a way to do it with a megger, (3 point test) and the second ground rod is what some people recomend, just do a google search and the can of worms tips over. My thought was if the soil is not that good why would 2 be better than one. This subject is worse than some of those related to wood burning here on hearth.con! :lol:

 

[fbelec]

Actually I looked it up and you do not use a meter or a megger, they make a special tool for checking the ground rod, the code person should be the one checking it not you, I would call him out on that.

hi oldspark

can you point me in the direction of this ground rod checker. the inspectors around here want it done with a megger. i don't know why, but thats what they want. and if the fix to getting my job to pass inspection is cheap like a extra ground rod thats what i do. but now if there is ground rod checker i need to know for less work.

frank

Oh boy, can of worms, the testers are pricey and I guess there is a way to do it with a megger, (3 point test) and the second ground rod is what some people recomend, just do a google search and the can of worms tips over. My thought was if the soil is not that good why would 2 be better than one. This subject is worse than some of those related to wood burning here on hearth.con! :lol:

nah. dealing with the inspectors that interpret the code wrong or different, or just want to have a big head. thats tuff.

 

[Tony H]

Ground rod Yes YOU WANT ONE when it's needed you want the shortest straightest path to ground to minimize damage to life and property.
You will only need a single ground rod for a shed and most buildings . We would only install ground plains when the ground was poor and we has lots of telephone and data equipment to protect.

 

[fbelec]

Ground rod Yes YOU WANT ONE when it's needed you want the shortest straightest path to ground to minimize damage to life and property.
You will only need a single ground rod for a shed and most buildings . We would only install ground plains when the ground was poor and we has lots of telephone and data equipment to protect.

hi tony
i've never done a ground plane. what's involved with doing it?

 

[feelingasi]

the best way to do this is to go buy some direct bury mobile home wire 2-2-2-4al, its about 1.80 a foot. put it in pipe. 1 1/4 is possible but 2" would be better.no more than 360 deg of bend in the pipe. bury a couple spare 3/4 for future. you may want to add a light that you can controll from the house,cable,internet, etc???. with the 4 wire system you should not install a ground rod. by doing so you establish a parallel path for fault current to travel in. this is an unlikely occurance but it can happen. at any one property, consisting of one service, the main panel should be the only point in the electrical that is bonded if you want to add a ground rod there go ahead. the #4 should be hooked to an auxillary ground bar inside your subpanel(you will have to purchase this separate), and do not bond the nuetral. all nuetrals from branch ckts go to nuetral bar, all bares or greens go to aux grnd bar. being in your shed does not make it any different that being a sub panel anywhere else in your home. it is not a separately derived system as it is not a standalone service nor is it derived from a XFMR. If you need code sections i will be more than happy to look them up. I'm just being lazy right now. 15 yr IBEW inside wireman.

 

[Tony H]

Ground rod Yes YOU WANT ONE when it's needed you want the shortest straightest path to ground to minimize damage to life and property.
You will only need a single ground rod for a shed and most buildings . We would only install ground plains when the ground was poor and we has lots of telephone and data equipment to protect.

hi tony
i've never done a ground plane. what's involved with doing it?

The terminology may not be correct but what we called a ground plane was not the typical RF antenna version but simply a series of ground rods tied together to provide a better ground and larger capacity from the building / equipment to ground.
What we did was put in five ground rods laid out in a grid with one central rod and the four other laid out in a somewhat box shape 6' to 10' apart and tie them all together and back to a ground bar and then a couple of grd wires back to the building.
There was a formula we used for sizing the wires.

 

[fbelec]

ya i know what you mean. i can't remember the name either. we do a ground like that on inground pools.