You have to be careful using that annex.
The true answer is to use software similar to ETAP or similar to create a model in order to accurately model the actual configuration you are going to use.
Otherwise, I can tell you that all of the derates that occur if you followe the descriptions to a...
You can take a look at: http://www.compleximaginary.com/
Its a Power PE exam prep website. Dont be too spooked as basic principles of a lot of things is what the PE exam is about.
That site has several very good youtube videos that go over basic concepts and problems, and how to work them...
Its larger drop than you would think.
I have never seen a light detection scheme were the detection isn't easily routed through the compartments.
Also, I do not diagree there is a bunch of empirically derived factors. However, the "reliance" is typically strictly dictated by Plant safety...
Light detection relays are typically fairly cheap and are indeed faster, thus typically reducing arc flash levels.
Arc Maint switches are also useful and extremely cheap.
Bus differential is fast, but I disagree it does a "far better job". Its also typically more expensive. Bus diff used...
If you are referencing something around 3MVA dry type transformers, a couple other items do consider:
- You can typically close couple and save yourself cable/non-seg connections
- No reason to have a NEMA 3R if its inside the building
- Can make connecting HRG very simple.
- No foundations...
If you are going to try that Waross, depending on cable size wouldnt it be an option just to have a 480-480 transformer in that feed?
Random bonus of possibly helping loadflow? ha
The fact that he cannot find the grid is not due to inexperience if you don't even have the original drawings.
Even a guy with 50 years of ground grid design is still stuck in the same spot without drawings.
Its a pure guess and a bad path to head down.
Depends on the application really...
As a general design standard? No, I am not a big fan. (no pun intended) Depending on the type of plant and the overall system design, believing that you will not be adding to that power feed over the life of a plant is not a smart idea.
Also, the design...
My main concerns would be, after your cable ideas:
1) C&I cabling is a huge concern. The small misc cabling within the gear can be a huge time sink if done poorly. Verify vendor point to points, track any cabling that will cross shipping splits for the gear (as they will need to be...