480v to 600v 3ph. using 2 single phase transformers 2

[Weiner]

Would anyone have a wiring diagram for converting from 480v
3 phase to 600 volt 3 phase using 2 single phase 480x240 volt transformers.

 

[jbartos]

Suggestion: Visit

http://www.acmepowerdist.com/ael11.html

for more info
Normally, you need three single phase transformers to convert three-phase power supply of one voltage system to another voltage system, if single-phase two winding transformers are to be used. Had it been possible, it would widely be used, and you would not post this question. For all practical purposes, the three single phase transformers are combined into one three phase transformer which you may used in your application.

 

[jeffs01879]

This transformation can be done with an open delta connection using two transformers, each rated 240x480 to 120/240, and connected as autotransformers.
For each transformer, connect the 240x480 winding for 480 volts, H2 to H3. Connect the 120/240 volt winding for 120 volts, X1 to X3 and X2 to X4. Connect the two windings in series, H4 to X1/X3.
Now connect the H1 terminal of each of the two transformers together. Connect the A phase of 480 volt circuit conductors to the H4/X1/X3 point of transformer no. 1, connect the B phase to the common H1 point of the two transformers and connect the C phase to the H4/X1/X3 point of transformer no. 2. Connect the A phase of the 600 volt circuit to the X2/X4 terminal of transformer no. 1, connect the B phase to the common H1 point (directly to the 480 volt B phase), and connect the C phase to the X2/X4 terminal of transformer no. 2
This connection can be used to transform either way, 480 to 600 or 600 to 480. Obviously it is a three wire connection, no neutral can be accommodated.
Each of the two transformers needs to be about 110VA for every 1000VA of three phase transformed capacity.
Most transformer manufacturers can provide you with the wiring diagram.
I used this arrangement many years ago when we had a customer with some 480 volt equipment who was renting for a short term a building with a 600 volt service.

 

[busbar]

Weiner, the two transformers have to be configured as 480V primary, 120V secondary, connected as an open-delta autotransformer. The total kVA that can be served from the bank will be 0.577x4 or 2.3x the combined transformer kVA. No neutral-connected loads can be served by this configuration, and you must provide properly rated 3-pole overcurrent protection on both sides of the bank. Additionally, there is a critical point not to have overcurrent devices installed, so follow the wiring diagram exactly.

The link pointed out by jbartos goes through a fairly detailed list of considerations. Given your load requirements, a supply house or transformer manufacturer should be able to size the transformers and provide a wiring diagram.

With stock single-phase transformers, there is no practical way to do this task with wye- or closed-delta arrangements.