Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com JEFFERSON ELECTRIC, INC. Buck-Boost Transformer Application Manual Revised on February 15, 2012 Table of Contents Introduction......................2 Choosing the Proper Transformer................2 III. Rapid Selector Charts ..................... 4 Single Phase Chart ....................4 Open Delta Chart ....................6 Wye Chart .......................
1-800-892-3755 www.jeffersonelectric.com Introduction Jefferson Electric Buck-Boost transformers are low voltage isolation transformers that can be connected in an auto-transformer arrangement to provide a convenient and economical way to raise or lower single and three-phase voltages from 5-20%. The auto- transformer arrangement allows smaller and less expensive Buck-Boost transformers to supply large power loads.
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com Step 2: What is the source and load voltage? ♦ -Are you stepping up or stepping down the voltage? o Stepping up: Go to the LV column in the charts and find your source voltage.
Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com III. Rapid Selector Charts Single Phase Chart (requires 1 transformer) High Catalog Load Voltage Voltage Number Required Diagram Diagram (LV) (HV) 416-12xx 0.37 0.56 0.94 11.2 18.8 56-B Amperes 3.95 5.93 9.89 19.7 29.6 39.5 59.3...
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com High Catalog Load Voltage Voltage Number Required Diagram Diagram (LV) (HV) 416-11xx 0.95 14.3 19.0 28.6 47.6 56-D Amperes 4.58 6.88 11.4 22.9 34.4 45.8 68.8 91.7 416-11xx 10.0 15.0 20.0 30.0 50.0 56-D Amperes 4.58...
Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com 3 Phase Open Delta WIRING DIAGRAM #9 (57-A) Transformer #1 Transformer #2 Part A (Transformer #1): Step 1: Connect X2, X4 & HIGH VOLTAGE AØ-Phase together. Step 2: Connect X1, X3, H2, H4 & LOW VOLTAGE AØ-Phase together.
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com WIRING DIAGRAM #10 (57-B) Transformer #1 Transformer #2 Part A (Transformer #1): Step 1: Connect X4 & HIGH VOLTAGE AØ-Phase together. Step 2: Connect X2 & X3 together. Step 3: Connect X1, H2, H4 & LOW VOLTAGE AØ-Phase together.
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com WIRING DIAGRAM #11 (57-C) Transformer #1 Transformer #2 Part A (Transformer #1): Step 1: Connect X2, X4 & HIGH VOLTAGE AØ-Phase together. Step 2: Connect X1, X3, H4 & LOW VOLTAGE AØ-Phase together. Step 3: Connect H2 & H3 together.
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com WIRING DIAGRAM #12 (57-D) Transformer #1 Transformer #2 Part A (Transformer #1): Step 1: Connect X4 & HIGH VOLTAGE AØ-Phase together. Step 2: Connect X2 & X3 together. Step 3: Connect X1, H4 & LOW VOLTAGE AØ-Phase together.
Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com Typical Questions What is the difference between an autotransformer and an isolation transformer? In an isolation transformer the input and output are completely separated and all the energy is transformed. In an autotransformer the input and output are electrically connected.
Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com Why does the nameplate read High Volts =120 x 240 and Low Volts = 12/24, when the chart shows that I can connect 208 volts in and 229 volts out ? The nameplate shows the rating for when the unit is used as an isolation transformer.
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Jefferson Electric Inc. 1-800-892-3755 www.jeffersonelectric.com called copper losses and increase as the load increases causing a larger voltage drop.) Since the current is dependent on the load, the voltage drop will fluctuate with the amount of load. The buck-boost units will correct the voltage drop at a constant percentage of the input voltage, if the input voltage changes as the load changes the output voltage will change at the same rate.
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