There is not any overhead lines, this is one of our largest 500kV subs from space perspective and the caps are in a corner all alone. The cans all tested good as of today so now I guess we have to start getting more creative to find the issue.
When we test energized it, I saw it rise from 0.2 to 0.6+ differential in a matter of twenty seconds. I do think manufacturing tolerances and aging can have a decent impact. Especially on something like this that is from the 80s. I really hate performing K sets to mask issues. That has...
Well that's cool, it worked for the CEV's but It wouldn't work for the comtrade files where I do think things get more interesting. Unfortunately, my technician only sent me the comtrade files from todays test energization i should be able to get the cev's tomorrow. Since we sat there and...
How exactly does that work with CIP sensitive relays given it details locations and settings. I did that before and got a few messages stating that it wasn't a smart idea from other forum members haha
I was called out to investigate a b-phase cap bank trip,It is one of the original caps on our system that has just always been an issue. It is an externally fused, grounded cap with two SEL 487V's using bus and mid-cap potential for voltage differential. I am being told the mid-cap ccvts have...
http://technotes1.blogspot.com/2015/10/phase-rotation-on-delta-delta.html?m=1
I'm a substation maitanence engineer and I just can't wrap my head around it. I personally was always taught you have to put phase rotation (ABC or ACB) as one of the highest priorities. He depicts that if you wire...
Whoops sorry i meant open delta so yes 2 transformers. The meter is used for local and SCADA. When i looked thru the satec manual it seems the wiring configurations don't really specify using voltages and currents from opposite sides of a delta wye transformer. They allow for the use of the open...
Hello,
We had a 69/13.2 delta wye bank fail a few months back and were able to find a new one sitting around somewhere. The issue I am running into is metering. The transformer doesn't have 3 low side CT's nor does it have 3 phase pots on the high side. The design has us using the high side...
That's where i messed up. After a long day of switching we put the bank in service at around 8 pm. Once energized we were running around tracking down a few other issues and the bank never tripped offline. Pulled event reports from all of the relays from both banks and somehow missed the 587...
Yeah 7-zip is the way to go. Once your in, to actually view .cev files, you will need acSELerator Analytic Assistant software. I believe without a license you can still view it with limited functionality
The issue is I work for a larger company, so its a lot of people stuck in their ways and if you aren't near the headquarters you aren't going to change that anytime soon. I always get the Swiss cheese analogy with protection redundancy. More slices from different blocks of cheese the less likely...
We are using a 487E as well as a 587. Currently the transformer is protected by 2 421's for high and low side lead protection, the 587 for primary differential, 2 551's for neutral protection on the transformer and ground bank, and the 487E for an overall differential. Thanks for your help...
This is something I have been harping on as well for the past few days... You are correct the PHROT in the settings is set for ABC and not for ACB. Someone managed to tell me it wasn't an issue and I had a hard time believing that setting was compensating for the phase offset. Where I made a big...
I am the commissioning engineer for the transformer, hence why I am eager to discover the issue since everyone likes to point the blame on me missing something during commissioning, so I only know enough protection knowledge to be deadly. I know there is a way to view harmonics thru the raw...
The issue I have is this can't happen every time they open the remote breaker whether for a requested outage or to add SF6 gas. The 587 is set very reasonably with a 0.3 pu and 40% slope 1 with slope 2 set to off. 2nd harmonic blocking is 15%
I am not too familiar with sending files and not images over a forum so if this isnt good for you let me know a better way
https://drive.google.com/open?id=1OIxARHBySAYfS_7W94pl9dzkqTvj41J9
A little too eager to wait until Monday when the protection engineers get back to work so I figured I would see what this forum knows about an issue we had on Friday with a 230/60kV transformer. It is brand new, has been in service for over two weeks through high and low load. Friday the...
