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How do I select the proper Buck & Boost transformer to go from 208V to 240V, or from 240V to 208V?

Issue:
Procedure for selection of SquareD/Schneider Electric Buck and Boost Transformers

Product Line:
LV Transformers

Environment:
Applies to all SquareD/Schneider Electric Buck and Boost Transformers

Cause:
Requirement to change a source voltage to a higher or lower load voltage

Resolution:

Use Buck & Boost catalog 7414CT0001, Buck & Boost `slide rule` 7414SP9901, the On-Line Buck & Boost Transformer Calculator at: http://buckboostcalculator.com/index.cfm,  or...

1. If the load is single phase:
A. Multiply 32 volts times the load amperage needed to obtain VA of Buck & Boost Transformer
B. Choose a `SV46` transformer of next larger standard size above the VA obtained in A.
Example: if load is 11 amperes, multiply 11 x 32 = 352VA, choose catalog number 500SV46B
C. Connect using wiring diagram #4 in Buck & Boost literature.
2. If load is three phase 3-wire:
A. Use same procedure as in single phase except two transformers must be used.
Example: if load is 27 amperes, multiply 27 x 32 = 864VA, choose (2) catalog number 1S46F
B. Connect using wiring diagram #6 in Buck & Boost literature
3. If load is three phase 4-wire:
A. Multiply 16 volts times the load amperage needed to obtain VA of Buck & Boost Transformer
B. Choose three `SV46` transformers, each of next larger standard size above the VA obtained in A.
Example: if load is 11 amperes, multiply 11 x 16 = 176VA, choose (3) catalog number 250SV46B
C. Connect using wiring diagram #7 in Buck & Boost literature
Warning: Three phase 4-wire loading requires a 3-phase 4-wire primary source for wiring diagram #7. Attempts to create a neutral with Buck & Boost Transformer connections can result in damage to transformers and/or load equipment!


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