Recent content by WindTurbinesAreFine

I'm not sure what a DS is, but we connect essentially everything to the grounding grid. Failing to bond above grade metallic objects within the substation to the below grade grid could produce unsafe touch potentials. From your list of equipment, I would connect all that you have listed...

Sorry, what I mean is that a 600:5 should be okay for your application. When we size our CTs, we assume that in general (it depends on the application and load) we won't be seeing more than 80% of the rated current of the upstream breaker. After calculating what 80% of the rated current is, we...

We generally use the rule of thumb that we size our CTs (on new construction) to 80% of the upstream breaker capacity.

GE Makes a unit called the Hydran that measures the health of the transformer: http://www.gepower.com/prod_serv/products/substation_md/en/downloads_en/hydranm2_fact_sheet.pdf As Waross mentioned, the water in the transformer tank could very likely be a result of a breakdown of materials on the...

Also, your satisfaction with the program will also slightly depend on the scale of your projects. If you are doing large scale utility projects where you need to also model the distribution/transmission system, CDEGS is more polished for that. I have found that the distribution/transmission...

I've been using WinIGS for close to a year now, and it is a very nice program, but really lacks some professional polishing to it. The user manuals that come with it are poorly written, and would be absolutely useless to someone new to grounding analysis. As well, there seem to be only 2...

Not enough power? How large is the panel?

Some sort of thermal covering or enclosure might do the trick.

You could make special crossarms for your riser pole so you could install station mount arrestors.

CYMGRD will not calculate the current split factor? You can use the tables in IEEE-80-2000 to estimate the split factor based on some assumptions. This will lower you GPR as jghrist has described, but each site is different and should be calculated.

Have you run any simulations yet with your preliminary design to see what you're up against? In general, what does your earth resistivity look like, <100 ohm-m, >100ohm-m?

True, which is why the clearing time shouldn't be chosen at random. This is one of those little inputs that has a huge effect on the outcome.

Do you have overhead lines coming into the substation, or is it underground cable? If you have overhead lines crossing over your fence, you are going to have big problems if that energized conductor falls on the ungrounded fence. The problem for you I suppose is that in order to limit the...

The software we use actually is preset to 250 milliseconds. We also compared this with the clearing time of our upstream protection and found that 250 ms is actually slightly on the conservative side anyway. We recently did a study using 500 ms when the client specifically asked us to. The...

Isolating the fence is not a good idea if you have overhead lines that cross over the fence. A line to ground fence on an ungrounded fence would surely kill a person. I agree with the statement of shock time affecting your results. You have to choose one that is realistic, yet conservative...