A few of our blown fuses didn't have an apparent cause (and no corresponding faults past feeder breakers), but several were due to L-G secondary faults within the substation (arrester failure, voltage regulator failure, snake, squirrel, etc.). In some cases the first fuse would blow and then...
I've always tried to set feeder overcurrent settings based on the rating of the conductor rather than the feeder load current (but I've never had a substation that only has one feeder). If there are normally open ties, you want to be able to pick up load from additional feeders if necessary...
I used to inspect distribution lines before signing off on RUS Form 990's and found countless poles that weren't guyed properly. Linemen seem to think nothing of eliminating anchors or shortening guy leads for their own convenience.
Replying to Palletjack,
Splitting the bus and installing a tie breaker is probably the best option, but that adds to the cost of the project.
In 25 years, I've never submitted a budget that didn't get cut (nor have I ever seen a CFO take the blame for the resulting equipment failures).
A previous utility that I worked for built several 115 kV lines using 959 ACSS-TW. These were all either radial lines to distribution substations or were normally-open loops.
Prior to switching over to the ACSS-TW, we used 795 ACSR as our standard transmission conductor but determined that the...
If the meter was replaced, and the old meter was electromechanical, it's possible that the old meter was registering slow and the new meter is just correct. I'd be interested in the knowing their typical consumption before and after the installation. Before my utility switched to solid state...
Minimum would be a three-way switch on a pole, if you are willing to accept that a fault on the tap will be cleared by the main line's protective device(s). You also have to be willing to accept that the line will be radial from there to the substation.
If budget allows, I like RRaghunath's...
What's interesting to me is that all of the substation ground grid calculations that I've seen assume there is about 6 inches of gravel in the substation (3 inches of crusher run/fines, then 3 inches of larger gravel). In reality, its rare to find a substation with anywhere near that much...
I hang out in the NESC world, so there may be other considerations if the NEC applies to your application, but...
It sounds like the only thing connected to the 13.8 kV side of the transformer will be the fuel cell system. In the event of a fault between the transformer and the 13.8 kV...
Potential inrush problems aren't just limited to tripping feeder breakers. You should also take a look at the source impedance and estimate the likely voltage dip that will result from the inrush current.
Several months ago, we connected a new industrial customer to a 69 kV radial transmission...
