Thanks for the responses. We generally use a fuse-"sacrificing" approach with our protective schemes. For us, this seems to give better coordination by allowing more margin between protective devices, and has resulted in fewer nuisance trips, especially during storms. In other words, we opt...
Does anyone know of a manufacturer that makes a 15kV class insulator to use
for the purpose of minimizing fault induced conductor gallop,due to magnetic forces and does the NESC allow insulators to be used for this purpose?
The utility company that I work for routinely installs a thin piece of sheet metal that is then nailed to the tops of our wood distribution poles. This company has done this practice for many years and still continues it, with the justification of protecting the pole top from rot (by capping...
What are some criteria to consider in letting a three-phase 18/24/30 MVA 154/13 kV power transformer sit idle for long periods of time. My particular unit has a nitrogen pressure system and heaters installed on the unit. Is there any detriment in letting the unit sit idle?
Does anyone know where I can obtain initial sag/tension charts for various sizes of acsr conductor for different ruling spans and temperatures? This is for a distribution feeder application in the medium loading district.
Sorry, the first file didn't take. I'll try again.http://files.engineering.com/getfile.aspx?folder=12eda109-3569-49e4-81d2-c0aad8533546&file=Type%20LON%20(ganged)[1].pdf
After some more googling, I came across this. Why do you not see these in the US?http://files.engineering.com/getfile.aspx?folder=c6f9043f-37e7-485c-9c4a-12d0e47b211c&file=Type%20LON%20(ganged)[1].pdf
Is there a device made to provide high-side protection of distribution transformers that opens all three phases as opposed to individual fused disconnects that allow the transformer bank to backfeed and single-phase?
Is there any advantage gained by running the cooling fans on a distribution substation transformer that is normally loaded on peak to approximately 70% of the base rating? This particular unit has two stages of fan forced air cooling with ratings of 18/24/36 MVA respectively. To my knowledge 17...
Interesting facts guys. This was the information that I was after.
Have any of you kept up with the loss reductions possible using capacitors? Our company, a rural municipal, was having line losses anywhere from 7.5 to 8.5 %. We reworked some of the existing cap installations, and our losses...
Thanks for the info. guys, but what i'm getting at is a way to minimize energy losses due to the reactive load. I'm looking for a proven method to optimally locate fixed and var switched capacitors without the luxury of having some of the newer modeling software that is available these days...
Does anyone have a good hand calculation method or methods for locating shunt capacitor banks on a three-phase 4 wire multigrounded distribution feeder, strictly from the standpoint of minimizing line losses?
After reviewing the voltage and current trends from the recorder, this looks very similar to a problem we had several months ago, with the same type customer complaints. If this is confined to just one phase, I would consider looking at the voltage regulator for that phase. The contacts on the...
