Question of Phase sequence

[capuchi]

Hi, we have a 2000KVA delta-wye 23KV/460V Oil filled transformer (T-1) feeding a 225KVA, delta-wye 460V/230V transformer (T-2) inturn feeding 3phase air conditioning equipment and lighting. Our cables and wires are color coded right from the LV side of T-2 up to the downstream panelboards' branch circuits. My question is . . . how do I change the phase sequence without disturbing the color coding of cables & wires. I intend to switch any two connections of the T-2 windings. Shall the switching of connections be in the primary or secondary? I'm sure there are experts out there who can provide the correct or appropriate solution. Thanks.

 

[dpc]

Switching any two phases, primary or secondary will change the phase sequence on the secondary.

I assume you realize that this will cause ALL of your 3-phase motors to rotate in the opposite direction. This is a much bigger concern than color coding of the phase conductors. Just use colored tape next time - it's a lot easier to swap.