LOL guys! I was looking at the other houses in my neighborhood, and they seem to have 5-10 of them per 25kVA transformer, too. I'm on the end of a row, which is the only reason why we just have 2, I think How can that work? Do they rely on freezing temperatures to keep the transformers from bursing into flames on cold winter days when everyone's heat pump goes to emergency resistive heater and there's suddenly a 150kVA demand? Is it even worse on down the distribution line? Guy I ran into on the street today while I was looking at the pole pigs told me a story of how MIS Utility mis-marked the underground feeders on a jobsite and he drove a metal stake into one- and watched the nearest pole pig explode into flames, and a few minutes later, the big neithbordhood transformer 2 blocks down exploded into flames as well.
Seems kinda pointless to upgrade the 150A breaker to 200A when the transformer is only rated for 104A.
Also, don't the cores saturate? I thought they were actually designed to saturate about 100% load in order to protect the conductors. Are they typically capable of 300% the rated kVA? That seems to be what I gather from what I could find on google. 2600A is about 25x the rating... How can they have a fault current so much in excess of the saturation point of the core? This one happens to be right in front of my house- maybe 100' of cable. Looks to be 4/0 aluminum, but it's hard to tell.
[This message has been edited by SteveFehr (edited 08-11-2006).]
