| Click to Post a New Message!
Page [ 1 ] |
|
|
|
Electrical Ground Question
I have poultry houses with some pretty expensive electronic equipment. It's not uncommon for electrical shorts to occur from time to time. The neutral and ground bars are bonded together inside the breaker box (3 wire system). Would it be better to separate the neutral and ground bars and run the ground bar directly to a ground rod?
|
|
 Add Photo
Bookmarks: |
|
| |
|
Electrical Ground Question
Let me add something to this scenario. You might say, the rest of the story or real story. When they were wiring up these control rooms, the electrician told his helper to cut the neutral/ground bonding bar out. The neutral wires are attached to the neutral bar, the ground wires are attached to the ground bar. The neutral bar is tied to the power company neutral. BUT, the ground bar isn't tied to shit.
Should I
A) run a jumper from the neutral bar to ground bar
B) run a wire from the ground bar to a ground rod.
C) Do both
|
|
Add Photo
Bookmarks: |
|
| |
|
Electrical Ground Question
I called him today and he said "he thought" I had a 4 wire system. Since his helper cut out the bonding bar, to drive a ground rod and tie the ground bar to it and to leave the neutral bar tied to power company neutral.
I talked to another electrician and he suggested I do the same.
|
|
Add Photo
Bookmarks: |
|
| |
|
Electrical Ground Question
Greg, these aren't sub panels. There is a 200 amp main service disconnect right under the electric meter. There's two sets of 3 wires going to each panel in tow different buildings. Below is an email from a friend of mine. This guy knows his shit and deals with high dollar electronics every day.
Billy,
Hey yes...it certainly has been a long time! Where you been! Last I heard you were having problems with your computer and e-mail system. Hope those problems got resolved. Hope everything is going well for you.
Okay now, understanding that you've made a serious investment in equipment to run your houses...then hired someone who claimed to be a trained professional to install this expensive equipment...and understanding that the equipment must be installed properly or it may get destroyed by lightening, power line transients, or any number of other power system anomolies...I would begin by doing the following, and in the same order:
1. Dig a shallow hole about 6' by 3' by 3 feet deep
2. Shoot "electrician" who installed your equipment
3. Dump body in aforementioned hole
4. Lime liberally and then cover with dirt
5. Go back in a couple of days and smooth over the depression from the body shrinking
Now that we have the "electrician" taken care of and out of the way we can get down to correcting what he did.
I assume he ran 220/240 volt AC power to your houses. This would be one leg, another leg, and a neutral line...L1, L2, and N on drawings or diagrams. This being the case your neutral line goes to ground, but only at the distribution transformer. This is as it should be. Don't mess with this.
Leave the neutral and ground bus bars separated.
I don't remember if your houses have concrete or dirt floors in the control equipment rooms. If they're dirt, cool. If they're concrete, I would plan on drilling a hole through it and then filling that in when we're done.
Do you know how far down your water table is? We need to get a ground rod down a couple of feet below the top level of the water table when it's at its lowest. Sometimes this requires an 8 foot rod, sometimes longer. I believe they come in 8, 10, 12, and 16 foot lengths. Let's hope the 8 footer will do and this is the shortest ground rod I would use.
I don't like steel ground rods even if they do meet code. I like solid copper or copper clad rods. Some supply houses will try to sell you a copper plated rod as a clad rod, they're lying to you. Plating is only several micro inches thick, millionths of an inch. A copper "clad" rod will have about a 1/32 to 1/16 inch thick layer of copper around the rod from end to end. If your dirt isn't too bad to dig in and you can use it, I would use solid copper when ever possible.
You need one rod for each control panel.
I would install the rod as close as possible to the control panel. Right below it would be great.
After you're done with this run a cable from the ground bus on the panel to your rod, clamp, and you're good to go. Ground cable - I like to use a braid type cable rather than a solid wire like the power company uses. Solid wire is okay for just a safety wire and low frequency AC, 60 Hz as with line power. One of the more serious issues you have to deal with is lightening, which is a very short duration, high energy content pulse. A ground cable for this is much better when there are many, many more strands of wire in the cable...the more the better. Without getting into the technical details and physics of why, this just presents a much lower impedance (which is a spiffy name for the AC resistance of a conductor) to high frequency energy...lightening. Copper braid isn't cheap, but do we want to protect thousands of dollars worth of controllers with a 10 dollar piece of wire? This is 1/2 inch copper braid. I would use 2 lengths, run in parallel, to ground my panel.
Hope this helps. Let me know if I can be of any further help Billy.
REB
ollar control computer?
|
|
Add Photo
Bookmarks: |
|
| |
|
Electrical Ground Question
why didn't your electrical inspector catch this?
Because the electrician and the inspector are the same person and both are idiots. He just happens to work for the company that put all the new equipment in. He's actually a decent electrician but is lazy as hell. I believe the only reason they keep him is he knows how to work on the controllers.
|
|
Add Photo
Bookmarks: |
|
| |
|
Page [ 1 ] | Thread 125490 Filter by Poster:
5 | 1 | 4 | 1 | 1 | 1 | 1 | 2 |
|
()
Picture of the Day
rockingo
Unanswered Questions
Active Subjects
Hot Topics
Featured Suppliers
|
Gas Generator Weather Protecti
03-03-2006, 11:17 
Digg It 
Del.icio.us