milmat1
"It Can't Do That !"
- Location
- Siler City, NC USA
- Occupation
- Controls Engineer
Something that has always bothered me ! Look at attached example.
Lets say you have incoming 480 100A service to the control cabinet. It is terminated to the fused disconnect, we'll say fuses are 100A. Then wires go to a power distribution block because the disconnect has only one port per phase for terminations. And you must feed multiple branch circuits.
From the PDB wiring splits up to the different circuits such as motor circuits, controls etc. Which are all smaller conductors. These smaller conductors are still only protected by the 100A main fuses until they reach the first branch circuit protection device.
In all the years I have been around, I have never found or seen a good solution to this, and I see it in every MCC / control cabinet. And it has always really bugged me..
Thoughts, Have you ever seen and wondered about this ? What is the solution ?
Lets say you have incoming 480 100A service to the control cabinet. It is terminated to the fused disconnect, we'll say fuses are 100A. Then wires go to a power distribution block because the disconnect has only one port per phase for terminations. And you must feed multiple branch circuits.
From the PDB wiring splits up to the different circuits such as motor circuits, controls etc. Which are all smaller conductors. These smaller conductors are still only protected by the 100A main fuses until they reach the first branch circuit protection device.
In all the years I have been around, I have never found or seen a good solution to this, and I see it in every MCC / control cabinet. And it has always really bugged me..
Thoughts, Have you ever seen and wondered about this ? What is the solution ?
