If this is in the US, it would fall under OSHA criteria which limits the voltage of any above grade appertenance to 50V or less. You are within this limit, but I never felt very comfortable with that 50V limit myslef. If you're measuring a constant potential, I'd question whether the fence was...
Sounds like you are describing two different types of tests, the standard fall of potential and the "90 degree" fall of potential. If you take your voltage measurements at a 90 degree angle from your current probe, then you can avoid having induced currents in your voltage leads. It's...
Steve,
Not sure what you are ultimately trying to accomplish here, but if you're trying to look at just induced voltage, I don't think that Malz is the right module. MALZ won't calculate induction for you. You would need to go to HiFREQ for that.
My recommendation would be to call SES...
"What happens in case there is a fault at the MV size of the substation?"
If you have a SLG fault of the MV side of the substation, I assume that this is a grounded source (let's say substation transformer is 115kV Delta - 13.8kV grounded Wye). The ground fault current will circulate within...
Brian,
I run into this issue quite a lot. You are correct to use zero transmission lines and 2 feeders. Even for a HV fault, the feeder nuetrals will help.
You should also consider a low side fault outside the substation. I've seen a few cases where this is actually worst case. Depends on...
Check out the Omicron website. They have an interesting test method utilizing the transmission phase wires for current path. I had this recently demonstrated. It helps to have grounding switches. Anyways, they have a video on thier website which may help at least visualize the test. I will...
Whenever I do a ground resistance test, I always do a soil resistivity measurement. It's probably the same meter, just use four pins instead of three.
This will help evaluate whether or not you were able to escape the zone of influence. That is if you really want to build an accurate...
I recently evaluated WinIGS for our company. For disclosure, I have been using CDEGS for several years now. I found WinIGS very clunky and difficult to use. There were several features that did not seem to work or at least, I couldn't figure them out. The biggest problem was tech support...
I am having a hard time finding information about nuetral grounding reactors. Hopefully you can help me with a few issues.
I'm replacing two 10/12.5 MVA auto-transformers with one 15/20/25MVA Delta-Zigzag. Voltage is 23-13.8kV. Planning needs a really low impedance on XFMR(2.18%) which is...
Bill,
I think I understand your issue a lot better now. To estimate the voltage ratings for your PRC's at the station is going to be difficult especially considering that these are older existing pipelines. The main reason is the resistivity of the coatings (for new FBE usually assume...
I would definitely not recommend ignoring this problem. Induced currents can be significant. Most new pipelines have a very good coating resistance which means that induced currents do not tend to just 'bleed off' by themselves. Under fault conditions, induced (and conductive) currents can...
cuky2000
You should look into IEC body resistance calculations. The difference is the body resistance is calculated according to stress voltage versus body resistance curves published in IEC Report 479-1. hope this helps.
Two programs for lightning protection:
SES (Safe Engineering Services) has a module called SES Shield
AGC (Advanced Grounding Concepts) has a program called WINIGS
