Will there be any load served either between where the 12.47 source is and this transformer, or between where the 24.9 source is and this transformer. I.E., is this a tie somewhere out on two distribution circuits?
If yes, I think I'd go with the five limb Yg-yg.
If no, I think it would depend...
I think mentorship, culture, support systems, processes, nature of the work, and the talents of the individual are all variables that make figuring out that number impossible/useless.
Here's a couple of 230kV risers:
These two may be in the neighborhood of 2000kcmil CU and 900A per cable @ 75% load factor:
https://www.google.com/maps/@33.4284814,-111.9620986,3a,70.4y,240.75h,109.62t/data=!3m6!1e1!3m4!1s23HxxKV2WObtctkQaDJqAA!2e0!7i16384!8i8192?authuser=0...
Depending on the distance between terminations and/or joints, what you mentioned is one technique that is sometimes employed to manage voltage or current on shields in 69kV+ transmission cables. Personally I haven't heard of or seen this done by US utilities on a distribution system. Honestly to...
waross, is this a Canadian practice or are you saying you think this is allowed by NEC (or NESC)? I think I recall you saying before that it's a common practice (in Canada) to place a neutral only on the last few spans before a transformer station. As far as I know such practices were prohibited...
crshears, prior to seeing your post here I felt inclined to read all of Max's posts and after having done so I'm pretty confident they're coming from some AI.
From C57.18.10-2021 IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers
From IEEE 1653.1-2016 IEEE Standard for Traction Power Rectifier Transformers for Substation Applications up to 1500 V DC Nominal Output
From IEEE 1653.2-2020 IEEE Standard for...
I think you're going to need either long term dynamics or load flow with profiles module to do any time series stuff. You will also probably find more support on the Cyme forums.
A service point is located inside the utility substation. The customer owns and installs the conductor to the service point. The service conductors are underground in conduit. Does 250.186 require a wire type supply-side bonding jumper from the service point to the service disconnect? 250.190...
Why do you suggest an AHJ would need to approve this in regards to the acceptability of installing the panel at this location? It is simply lowering the "available fault current" as mentioned in 409.22.
