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Thanks all of you for your replies to date. @scottf I'd love to discuss this with you offline, what's the best way to direct message without sharing our private emails? One thing I wonder is why, with a high impedance ohmmeter, the voltage to station ground of the VT secondary wasn't elevated...

Hi All, Thanks in advance for your thoughts. I post once every few years or so, but read often. Application is in North America. We had a brand new 72 kV dry-type cast epoxy resin voltage transformer fail catastrophically recently. No personnel were harmed, but easily could have been...

Thanks all! @3DDave - Thanks, I should have mentioned I'm in Canada, neither seller will accommodate shipments here unfortunately. @davidbeach - Fair ;) To further underline your point, Vol.1 is free here: https://archive.org/details/in.ernet.dli.2015.278653/page/n47/mode/2up @dpc - Much...

Hi All, hope you're all doing well. A Practical Guide to Short-Circuit Calculations by Conrad St. Pierre https://www.worldcat.org/title/practical-guide-to-short-circuit-calculations/oclc/53905296 This is a long shot, but I find myself routinely trying to find this much coveted and deeply out...

Thanks Compositepro!

Thanks For The Feedback! Consistency means oven dry weight of pulp. We may just do manual sampling given the difficulties. Microwave is an option, but depends on conductivity and entrapped air, still following that up. Radiometry can't sense below 2% consistency, and optical might work but...

Hi Folks, Thanks in advance for your time in reading this. First time poster to this group. As a forewarning, I've spent more time on the Power T&D group, so please show mercy :) I'm supporting a process upgrade that requires consistency measurement of hot water with some residual pulp (water...

This is a broad question. In general separate protection is provided for generators vs GSU Transformers in power plants as they are logically distinct electrical entities. Though in some (let's say often small and or remote) applications it's fine to protect the GSU and Generator at a single...

Thanks Jghrist, I'm still confirming code requirements, but I can say that the majority of transmission lines, and industrial distribution lines that I've seen that don't have a neutral do not have a ground conductor supplied (code or not). I have an estimated worst case grid resistance to...

Hi bspace123, According to the manual, N is the turns ratio of the CT, the manual is formatted so that the N is hidden at the end of the line above its definition. It looks like the relay is missing a division sign before the N which would make the equation work. That or they intend the Vs...

Thanks Stevenal and David, Yes Stevenal's point is the direction I was headed into. I wasn't looking at the two faults as independent contingencies. But in my application with overvoltages controlled by LRG and relay response I'm willing to disregard a weak arrestor (which I suppose that...

Thanks Bill and HamburgerHelper for your follow-ups, HamburgerHelpler: that's impressive that some utilities use interrupting capability. I suppose for solidly grounded systems it bears a bit more reason as the current levels are so high. For a large enough utility I suppose it just allows them...

@wroggent: I'm not 100% final on this, but I don't think so. Definitely don't think there's a bonding requirement, as the only continuous parts to the pole line system are current carrying. This application is similar to a transmission line in that sense.

@wroggent: yes that's right. If this were say a high resistance ground, in certain applications I could entertain the possibility of an insulation failure at one end, after a SLG at the other. My initial thinking was I'm being overly careful in my question here, but I just wanted the support of...

Thanks Both of You for your time and thoughts, 1. John: yes I believe those are both real scenarios to develop LL and LLG faults, but will result in a majority of the fault current flowing through the phases. My deeper concern is a bulk return via earth alone (SLG fault at one end, followed by...

Hi Electrical Folks, I am establishing the worst case ground fault current to perform GPR and Step and Touch calculations for a new 15kV substation. IEEE 80 indicates that LLG faults should be considered in addition to SLG faults. However, my industrial application is low resistance ground. In...

Thanks Bill for the detailed pointers, for some reason I'm a chicken to provide the hacksaw cuts (except for brown-field quick mod), though totally would work once you introduce the airgap flux impedance - MacGyver would not approve of my lame impracticality ;)

Thanks Bill, Table 1, col 2 are what I'm after! As I'm >=100% spacing I shouldn't have to derate by table 5b no? I'm still a bit worried about current sharing, but can see why you don't think it's a big deal for such a short run. I guess my concern was that for such a short run the impedance...

Hi Eng-Tips Electrical Community, This is my first post though I'll admit I've been a ghost-reader for some time. Many thanks for all the helpful posters I've benefited from in the past. I'm an electrical engineer working on a low voltage transformer secondary cable application and am seeking...