BJC:
Thanks for the tips. The field consultant of our utility has suggested using (3) single-phase 25KVA transformers. When I asked how many amps will be feeding my new 200A panel, they were unable to tell me. Thus I will dig deeper to find the answer.
I appologize for my ignorance.
I went to school for electronics engineering years ago.
I work for a utility, however a different department takes care of the transformer work.
I am only trying to gain a better understanding of the design criteria. I could hire a consultant but I thought this was...
rbulsara:
Yes, we are changing our utility service to a grounded-Y system on the 480 side to meet arc-flash requirements.
Yes, I believe that the utility service needs to be increased in sized for our 200A panel.
Yes, we are upgrading our 480VAC panel from a 100A to a 200A panel.
Few more...
Thanks for the response.
Could you please show me in detail, step-by-step, how you calculate the total available current using (3) single-phase transformers? Do you overdrive these transformers? The field consultant for the utility is planning to install (3) 25KVA transformers, however, I am...
Overview: In an industrial building, I am upgrading our current 3-phase 480VAC 100A panel to a 200A panel. The transformers,7200:480 step-down, suppling the power off the utility pole, are configured open-delta (also called Wild Leg) using (2) 25KVA transformers.
Question: What size and how...
I have a 13.8KV station service feeding a stepdown transformer to 480VAC for a distribution panel. Off of one breaker, the 480VAC feeds into another isolation transformer (480/480); this power goes out to a floating structure.
Question:
Recently, we have noticed the voltage swinging as high as...
My decision...
There were two different choices available that were close to the line-to-line voltage of 13.8KV.
Choice 1: 12.7KV MCOV (15KV duty cycle), with max discharge voltage at 10KA (8/20us surge) of 37.9KV.
Advantage: 37.9KV < 40KV (BIL) thus providing plenty of protection for the...
Sorry if this is being resent. The previous thread was accidently removed.
Problem: The existing 40 year old porcelain station class lightning arresters that are protecting a generator have failed and need replacing (one for each phase).
Generator info: I have a 13.8KV Hydro Generator...
