Step-Up, Step-Down Transformer System Design

[JP23]

Hoping to get some opinions on this outdoors underground (all conductors CU) step-up,step-down design.
The transformers are standard 50 KVA 3R dry type. The 1-line shows a 200 amp 120/240V fused meter main
feeding 3 #3/0, 1#4 to a 200 amp 2p fused disconnect and then to a 240/480V
step-up transformer. It shows another 100 amp 2p disconnect after the transformer feeding 3?# 350 MCM 1600' to
another 100 amp 2p disconnect and then 2#1,1#6G feeding a 480/240V step-down transformer. The secondary
conductors from the transformer show 2 #1?,1#8? to another 200 amp 2pole fused disconnect and then 3# 3/0, #4G
ground to a 200A main breaker in a load center.
After some 2014 NEC research in transformer protection, conductor protection and required disconnecting means
I'm thinking it could be way more simple, a 2 wire system from the meter/main to a single fused disconnect.
before the step-down transformer and then a 3 wire to the load center. What's the most efficient design possible?
Some of the Articles/parts/tables I found to be applicable are:

450.3 (B) Transformer overcurrent protection
450.3(B) Transformer overcurrent protection table.
240,21 (C)(1) & (C)(4) conductor protection by primary overcurrent device
450.14 Disconnecting means.

Any suggestions or opinions are appreciated.

 

[texie]

Here is the most efficient way I have seen.

 

[don_resqcapt19]

If the rating of the service OCPD does not exceed 125% of the transformer rated primary current the primary disconnect for the 240/600 volt transformer could be eliminated.

 

[just the cowboy]

How are they using #1 to feed 200 amp

How are they using #1 to feed 200 amp

How are they feeding the 200 amp on the secondary disconnect with #1, It will still have 200 amps protection.

 

[texie]

If the rating of the service OCPD does not exceed 125% of the transformer rated primary current the primary disconnect for the 240/600 volt transformer could be eliminated.

I would agree. Even more cost efficient.

 

[JP23]

Thanks

Thanks

I appreciate the responses. I was thinking the conductors between transformers would
be considered a feeder and should include an EGC.

 

[JP23]

I think they meant to show 3/0 CU instead of #1.

I think they meant to show 3/0 CU instead of #1.

How are they feeding the 200 amp on the secondary disconnect with #1, It will still have 200 amps protection.

There's definitely a few issues with the design that need to be corrected.

 

[JP23]

It making more sense now.

It making more sense now.

I appreciate the responses. I was thinking the conductors between transformers would
be considered a feeder and should include an EGC.

I read the exception and I see where an EGC would redundant and a parallel path in that design.