Grounding training

[enkwizative]

Does anyone know where I can find a GOOD substation grounding course? Preferrably in a classroom setting, but an online course, or even a tutorial cd/dvd will do. My company has training, but not on specific topics such as grounding. If anyone can recommend such a class, etc, it will be greatly appreciated.

I'm located in NYC.

 

[jghrist]

Try Integrated Grounding System Design and Testing, a four day short course at Georgia Tech. See

http://www.pe.gatech.edu/conted/servlet/edu.gatech.conted.course.ViewCourseDetails?COURSE_ID=384

 

[Zogzog]

Big topic.

Ground grid design, ground system testing, or personal protective grouding (Equipotential Grounding)?

I know a good course for 2 of those topics.

 

[enkwizative]

Thanks guys.

jghrist: thanks, but i'm in NYC. i dunno if my company will pay for an out-of-state course. i'll ask them, though.

zogzog: thanks. would you send me some info?

 

[Zogzog]

Sure, on which course?

They wont be in NYC or NY, or east coast even. Unless you get lucky and hit the scheduled remote class.

 

[enkwizative]

thanks, zogzog. But I asked my supervisor about it and he said the company won't pay for classes out of NYC. What do you mean by "scheduled remote class?"

In the event I cannot get to a traditional class, I'm open to an online class, or even some sort of "training series" on DVD.

anyone?

 

[Zogzog]

What topic? What do you need to learn about grounding? Thats not too much more specific than I want to find a class about electricity.

 

[enkwizative]

Substation grounding(ground grid design), equipotential grounding, step and touch potential.

My company is building new substations and we are generally copying what was done for the previous stations. While I think that copying is good for scheduling and deadlines, I don't think we get a good enough understanding about the various systems by copying.

 

[jghrist]

My company is building new substations and we are generally copying what was done for the previous stations.

Substation grounding design is very dependent upon local conditions such as ground resistivity, available fault current, and characteristics of connected lines. Unless the design being copied is overly conservative, there is not much assurance that NESC station grounding requirements are met.

 

[Zogzog]

Thats something that should already be know by a company designing substations. I dont think you can learn that froma DVD, jghirst had a good recomendation for a school.

This is a good equipotential grounding seminar, but not in NY, I dont think you will find anything there.

http://www.hubbellpowersystems.com/powertest/training/util_train.html

 

[enkwizative]

Thanks for the replies guys.

Maybe I should've noted that we have an outside company perform the grounding study for us. They do all the tests necessary and come up with a recommended scheme, including: what size ground conductor for the main grid, how many ground rods, ground rod and grid spacing, etc. From there we take the information and put it on our drawings. We then add any take-offs for our equipment.

There were a couple of issues discussed in one of our meetings, and since I am pretty new to grounding, it wasn't clear to me.
One being this: we require the main ground grid to be 2ft below finished grade. That's spec., so that's ok with me. But they mentioned that any grounding of the upper elevations should have risers from the main ground grid below, a ground loop(3ft from wall), and take-offs for equipment. This is according to a first-line supervisor. I didn't agree. Previously I had been providing a grid for each elevation.
question: why shouldn't we have a ground grid on any/all elevations? Wouldn't that be more safe? Is it a waste of copper?

 

[Zogzog]

Yes, that would have been good to mention, I feel better now.

Either way is fine, you get what you pay for. I am not too knowledgeable on ground grids of upper elevations but I believe they use the rebar in the floors that already exists and then preferably a ring around the perimiter as you mentioned.

There are some ground grid gurus in here, I am sure you will a better answer shortly.

 

[SteveFehr]

Enkwizative, is this an electronic facility? Signals generated on the equipment ground at electronic facilities are typically at high frequencies and experience high inductive loss on a typical NEC-type single-point ground system. In these cases, an equipotential ground grid parallel with the earth functions as a capacitor and has very good performance at shunting this current to ground, even if it's not physically in contact with the earth. It's not so effective when on higher floors, so the priority there is to minimize the length of wire between the equipment and the ground.

If you're looking for design guidance, MIL-HDBK-1012/1 is free for download, and a very good design guide for electronic facilities. The DoD has other documents for substations, power transmission and grounding/bonding, too. They may not necessarily be directly applicable to you, but they almost invariably represent good engineering practice and are a good reference for where the code books let off.

 

[jnunner]

I know you've said that your company won't send you out of state, but if you want to get a good understanding of grounding, you could try kinectrics, who are offering a 2 day course out of Chicago or Toronto. With the low cost of the course, I think you could justify the expense of going out of state considering the practical knowledge you would gain. It's also a good idea to jot down some questions you have prior to attending, and ambush the instructor with them when you get the chance.

http://www.kinectrics.com/en/seminars/CoursesPage.html

When you are speaking of upper elevations, could you be more specific? From the mention of risers and takeoffs for equipment, I would have thought that you were talking about a substation structure, except I don't understand what you mean by a grid for each elevation, and the other posts assume that you are talking about some sort of building.

 

[enkwizative]

Thanks for the reply, jnunner. by upper elevations i mean the "second", "third", etc. floor. the main grid is located 2ft below the lowest level. now, imagine a similar grid under each elevation of the building, connected by risers from the grid below it. and by takeoffs i mean for equipment located on said elevations. did that answer your question?

 

[jnunner]

If I understand you correctly this is an indoor substation facility. My apologies, I don't have any experience with that grounding that sort of installation.