Dry Type Distribution Transformers Buck-Boost transformers are small, single phase, dry type distribution transformers designed and shipped as insulating/isolating transformers. They have a dual voltage primary and a dual voltage secondary. These transformers can be connected for a wide range of voltage combinations. The most common use is to buck (lower) or boost (raise) the supply voltage a small amount, usually 5 to 27%. Buck-boost transformers are in compliance with NEC Article 210.9, Exception 1 when field connected as an autotransformer. The major advantages of Buck-boost transformers are their low cost, compact size and light weight. They are also more efficient and cost less than equivalent isolation transformers. When connected as an autotransformer, they can handle loads up to 20 times the nameplate rating. A buck-boost transformer is the ideal solution for changing line voltage by small amounts. When a buck-boost has the primary and secondary windings connected, per recommended instructions, it becomes an autotransformer. Now, only the secondary windings are transforming voltage and current. The majority of the kVA load passes directly from the supply to the load. This is the reason buck-boost transformers can supply a load with a much larger kVA rating than the nameplate indicates. Low voltage lighting control applications SolaHD buck-boost transformers are designed to supply power to low voltage lighting circuits, control panels or other systems requiring 12, 16, 24, 32, or 48 Volts. When connected as an insulating transformer (by following the wiring diagram located after the specification tables on the inside of the transformer case), the transformer's capacity matches the nameplate kVA rating. SolaHD buck-boost transformers are also suited for low voltage landscape lighting. They are UL Listed for outdoor service and their compact size makes them the perfect solution for providing power to accent lighting applications. Electrical Connection diagrams are shown at the end of this section. Use dimmers on the output of the transformer that are designed and rated for use with magnetic loads. We strongly recommend contacting the dimmer manufacturer for advice on your specific lighting application. Certifications and Compliances * 246 Listed - UL 506 - CSA C22.2 No. 66 E77014 Accessories * Surge Protective Devices * Active Tracking(R) Filters Selection Steps 1. Input Line Voltage Measure the supply voltage with a voltmeter. 2. Voltage Required for the Load Check the load equipment to determine the voltage requirement. 3. kVA or Ampere Rating of the Load Find either the load kVA or the load amperage requirements. This information is listed on the nameplate of the load equipment. 4. Frequency Either 50 or 60 Hz. The frequency of the transformer must match the frequency of the load. 5. Number of Phases Single or three phase line and load must match. (A transformer cannot convert single to three phase.) A common application is to make a single phase connection from a three phase supply by using one phase of the three phase supply circuit. Be careful not to overload that phase of the three phase supply. For buck-boost applications the supply must provide load kVA - not just the nameplate rating of the buck-boost. Refer to the Selection Tables on the following pages. Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Three phase, buck-boost applications require two or three transformers. Check the "Quantity Required" column of the Three Phase Selection Tables for the exact quantity. Fusing Buck-Boost Transformers For determining the correct size of breaker or fuse for a given range of input or output ampere ratings, refer to Section 450.4, of the National Electric Code (NEC). Where an overcurrent protection device is required, the electrical connections and selection tables will reference appropriately. Using the Selection Tables 1. Determine if you are trying to Boost (raise) or Buck (lower) your voltage. Select an input/output voltage combination that comes closest to matching your application from the appropriate single or three phase charts on the following pages. 2. Move across your selected input/output voltage row to the amperage or kVA rating closest to, but greater than the rating required by your load. 3. Reading the top of the column will give you the catalog number of the exact buck-boost transformer you need. See the Specification Tables on the next page. 4. Connect the transformers according to the diagram indicated. See the Electrical Connections section at the end of this section. Connection diagrams are packed with each transformer. Overcurrent devices OC-1a and OC-1b are shown correctly installed in accordance with NEC 450.4. Locating an overcurrent device in series with the shunt winding anywhere between A and B is not permitted. The shunt winding is the winding common to both the input and the output circuits. Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 247 Dry Type Distribution Transformers Specification Tables Group 1 - 120 x 240 Volt Primary, 12/24 Volt Secondary KVA Catalog Number Maximum Secondary Amperage 12 V 24 V Height in (mm) Width in (mm) Depth in (mm) Approx. Ship Weight lbs (kg) Design Style Elec Conn Non-Encapsulated - 50/60 Hz, Single Phase 0.05 HS19B50 4.16 2.08 6.00 (152.4) 4.00 (101.6) 3.00 (76.2) 2.0 (0.91) 2 1 0.1 HS19B100 8.33 4.16 6.00 (152.4) 4.00 (101.6) 3.00 (76.2) 4.0 (1.82) 2 1 0.15 HS19B150 12.5 6.25 7.50 (190.5) 4.00 (101.6) 4.00 (101.6) 5.0 (2.27) 2 1 HS19B250 20.8 10.4 7.50 (190.5) 4.00 (101.6) 4.00 (101.6) 8.0 (3.64) 2 1 0.25 Encapsulated - 60 Hz, Single Phase 0.5 HS19F500B 41.6 20.8 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 22.0 (10.00) 3 1 0.75 HS19F750B 62.5 31.2 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 27.0 (12.27) 3 1 HS19F1B 83.3 41.6 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 28.0 (12.73) 3 1 HS19F1.5A 125 62.5 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 38.0 (17.27) 4 1 166.6 83.3 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 45.0 (20.45) 4 1 1 1.5 2 HS19F2A 3 HS19F3A 250 125 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 55.0 (25.00) 4 1 5 HS19F5A 416.5 208.3 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 100.0 (45.45) 4 1 625 312.5 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 135.0 (61.36) 4 1 Approx. Ship Weight lbs (kg) Design Style Elec Conn 7.5 HS19F7.5A Group 2 - 120 x 240 Volt Primary, 16/32 Volt Secondary KVA Catalog Number Maximum Secondary Amperage 16 V 32 V Height in (mm) Width in (mm) Depth in (mm) Non-Encapsulated - 50/60 Hz, Single Phase 0.15 0.25 HS20B150 9.38 4.69 8.00 (203.2) 4.00 (101.6) 4.00 (101.6) 6.0 (2.73) 2 2 HS20B250 15.6 7.81 8.00 (203.2) 4.00 (101.6) 4.00 (101.6) 8.0 (3.64) 2 2 Encapsulated - 60 Hz, Single Phase 0.5 0.75 1 1.5 HS20F500B 31.2 15.6 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 22.0 (10.00) 3 2 HS20F750B 46.8 23.4 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 27.0 (12.27) 3 2 HS20F1B 62.5 31.2 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 28.0 (12.73) 3 2 HS20F1.5A 93.7 46.8 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 38.0 (17.27) 4 2 2 HS20F2A 125 62.5 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 45.0 (20.45) 4 2 3 HS20F3A 187.5 93.7 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 55.0 (25.00) 4 2 HS20F5A 312 156 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 100.0 (45.45) 4 2 HS20F7.5A 468 234 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 135.0 (61.36) 4 2 5 7.5 Note: Weights and dimensions may change and should not be used for construction purposes. 248 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Specification Tables - continued Group 3 - 240 x 480 Volt Primary, 24/48 Volt Secondary KVA Catalog Number Maximum Secondary Amperage Height in (mm) Width in (mm) 24 V 48 V 3.13 8.00 (203.2) 4.00 (101.6) 8.00 (203.2) 4.00 (101.6) Depth in (mm) Approx. Ship Weight lbs (kg) Design Style Elec Conn 3.00 (76.2) 5.0 (2.27) 2 3 3.00 (76.2) 8.0 (3.64) 2 3 Non-Encapsulated - 50/60 Hz, Single Phase 0.15 HS22B150 6.25 0.25 HS22B250 10.4 5.2 0.5 HS22F500B 20.8 10.4 8.00 (203.2) 6.00 (152.4) 5.00 (127.0) 22.0 (10.00) 3 3 0.75 HS22F750B 31.2 15.6 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 27.0 (12.27) 3 3 HS22F1B 41.6 20.8 10.00 (254.0) 6.00 (152.4) 5.00 (127.0) 28.0 (12.73) 3 3 HS22F1.5A 62.5 31.2 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 38.0 (17.27) 4 3 Encapsulated - 60 Hz, Single Phase 1 1.5 2 HS22F2A 83.3 41.6 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 45.0 (20.45) 4 3 3 HS22F3A 125 62.5 12.00 (304.8) 10.00 (254.0) 7.00 (177.8) 55.0 (25.00) 4 3 5 HS22F5A 208 104 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 100.0 (45.45) 4 3 HS22F7.5A 312 156 17.00 (431.8) 14.00 (355.6) 9.00 (228.6) 135.0 (61.36) 4 3 7.5 Note: Weights and dimensions may change and should not be used for construction purposes. 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(c) January 2017 249 Dry Type Distribution Transformers Electrical Connections for Low Voltage Applications 120 X 240 Volt Primary, 12/24 Volt Secondary Taps: None 1 = Earth Ground 120 X 240 Volt Primary, 16/32 Volt Secondary Taps: None 2 240 X 480 Volt Primary, 24/48 Volt Secondary Taps: None 3 H1 H3 H2 H4 H1 H3 H2 H4 H1 H3 H2 H4 X1 X3 X2 X4 X1 X3 X2 X4 X1 X3 X2 X4 Primary Voltage Interconnect Connect Lines To Primary Voltage Interconnect Connect Lines To Primary Voltage Interconnect Connect Lines To 240 H2 to H3 H1 & H4 240 H2 to H3 H1 & H4 480 H2 to H3 H1 & H4 120 H1 to H3 H2 to H4 H1 & H4 120 H1 to H3 H2 to H4 H1 & H4 240 H1 to H3 H2 to H4 H1 & H4 Secondary Voltage Interconnect Connect Lines To Secondary Voltage Interconnect Connect Lines To Secondary Voltage Interconnect Connect Lines To 24 X2 to X3 X1 & X4 32 X2 to X3 X1 & X4 48 X2 to X3 X1 & X4 12-0-12 X2 to X3 X2 to X1-X2-X4 16-0-16 X2 to X3 X2 to X1-X2-X4 24-0-24 X2 to X3 X2 to X1-X2-X4 12 X1 to X3 X2 to X4 X1 & X4 16 X1 to X3 X2 to X4 X1 & X4 24 X1 to X3 X2 to X4 X1 & X4 HS19 and S19 Series 250 HS20 and S20 Series HS22 and S22 Series Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Design Styles W D H Style 1- Ventilated Style 2 - Non-Encapsulated Style 3 - Encapsulated Style 4 - Encapsulated Custom Design Styles Style 5 - Encapsulated Available for all encapsulated kVA sizes (For Type 4, 12 and 4X) Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 251 Dry Type Distribution Transformers Selection Tables: Single Phase Table 1: Using Group 1 (120 x 240 V Primary, 12/24 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS19B50 HS19B100 HS19B150 HS19B250 HS19F500B HS19F750B HS19F1B BOOSTING 100 109 189 120 120 208 1 1 1 B1 A1 D1 kVA 0.25 0.5 0.75 1.25 2.5 3.75 5.0 Load Amps 2.08 4.16 6.25 10.4 20.8 31.2 41.6 Fuse Size 6.0 10.0 15.0 25.0 35.0 50.0 70.0 kVA 0.5 1.0 1.5 2.5 5.0 7.5 10.0 Load Amps 4.16 8.33 12.5 20.8 41.6 62.5 83.3 Fuse Size 10.0 15.0 20.0 30.0 60.0 90.0 125.0 kVA 0.43 0.87 1.3 2.16 4.33 6.49 8.65 Load Amps 2.08 4.16 6.25 10.4 20.8 31.2 41.6 6.0 10.0 15.0 15.0 30.0 45.0 60.0 kVA 0.87 1.73 2.6 4.33 8.65 13.0 17.3 Load Amps 4.16 8.33 12.5 20.8 41.6 62.5 83.3 Fuse Size 197 208 1 C1 Fuse Size 208 218 ** 229 240 1 1 D1 D1 6.0 15.0 20.0 30.0 60.0 90.0 110.0 kVA 0.48 0.95 1.43 2.38 4.77 7.15 9.54 Load Amps 2.08 4.16 6.25 10.4 20.8 31.2 41.6 Fuse Size 6.0 10.0 15.0 15.0 30.0 45.0 60.0 kVA 0.5 1.0 1.5 2.5 5.0 7.5 10.0 2.08 4.16 6.25 10.4 20.8 31.2 41.6 6.0 10.0 15.0 15.0 30.0 45.0 60.0 20.0 Load Amps Fuse Size kVA 229 240 1 C1 Load Amps Fuse Size 1.0 2.0 3.0 5.0 10.0 15.0 4.16 8.33 12.5 20.8 41.6 62.5 83.3 6.0 15.0 20.0 30.0 60.0 90.0 110.0 BUCKING 132 ** 144 ** 229 120 120 208 1 1 1 A2 B2 D2 kVA 0.55 1.1 1.65 2.75 5.5 8.25 11.0 Load Amps 4.58 9.16 13.75 22.9 45.8 68.7 91.6 Fuse Size 10.0 15.0 20.0 30.0 60.0 80 110 kVA 0.3 0.6 0.9 1.5 3.0 4.5 6.0 Load Amps 2.5 5.0 7.5 12.5 25 37.5 50.0 Fuse Size 6.0 10.0 15.0 15.0 30.0 40.0 60.0 kVA 0.48 0.95 1.43 2.38 4.77 7.15 9.54 Load Amps 2.29 4.58 6.88 11.4 22.9 34.4 45.8 6.0 10.0 15.0 15.0 30.0 40.0 60.0 Fuse Size 252 ** 264 ** 240 240 1 1 C2 D2 kVA 1.04 2.1 3.15 5.25 10.5 15.7 21.0 Load Amps 4.34 8.75 13.13 21.8 43.7 65.6 87.5 Fuse Size 10.0 15.0 15.0 30.0 60.0 80.0 110.0 kVA 0.55 1.1 1.65 2.75 5.5 8.25 11.0 Load Amps 2.29 4.58 6.88 11.4 22.9 34.3 45.8 6.0 10.0 15.0 15.0 30.0 40.0 60.0 Fuse Size * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 252 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Single Phase Table 1: Using Group 1 (120 x 240 V Primary, 12/24 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS19F1.5A HS19F2A HS19F3A HS19F5A HS19F7.5A BOOSTING kVA 100 120 1 B1 Load Amps Fuse Size kVA 109 189 197 208 218 ** 229 120 208 208 229 240 240 1 1 1 1 1 1 A1 D1 C1 D1 D1 C1 7.5 10.0 15.0 25.0 37.5 62.5 83.3 125.0 208.0 312.0 100.0 125.0 200.0 350.0 500.0 15.0 20.0 30.0 49.9 75.0 Load Amps 125.0 167.0 250.0 416.0 625.0 Fuse Size 175.0 250.0 350.0 600.0 1000.0 kVA 13.0 17.3 26.0 43.3 64.9 Load Amps 62.5 83.3 125.0 208.0 312.0 Fuse Size 90.0 125.0 175.0 300.0 450.0 kVA 26.0 34.7 52.0 86.5 130.0 Load Amps 125.0 167.0 250.0 416.0 625.0 Fuse Size 175.0 225.0 350.0 600.0 1000.0 kVA 14.3 19.1 28.6 47.6 71.4 Load Amps 62.5 83.3 125.0 208.0 312.0 450.0 Fuse Size 90.0 125.0 175.0 300.0 kVA 15.0 20.0 30.0 49.9 74.9 Load Amps 62.5 83.3 125.0 208.0 312.0 Fuse Size 90.0 125.0 175.0 300.0 450.0 kVA 30.0 40.1 60.0 99.8 150.0 Load Amps 125.0 167.0 250.0 416.0 625.0 Fuse Size 175.0 225.0 350.0 600.0 1000.0 BUCKING kVA 132 ** 120 1 A2 16.5 22.0 33.0 54.9 82.5 Load Amps 137.5 183.3 275.0 457.6 687.5 Fuse Size 175.0 225.0 350.0 600.0 800.0 kVA 144 ** 229 252 ** 264 ** 120 208 240 240 1 1 1 1 B2 D2 C2 D2 Load Amps 9.0 12.0 18.0 30.0 44.9 75.0 100.0 150.0 249.6 374.4 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 14.3 19.1 28.6 47.6 71.4 Load Amps 68.8 91.6 137.5 228.8 343.2 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 31.5 42.0 63.0 104.8 157.5 Load Amps 131.3 174.9 262.5 436.8 656.3 Fuse Size 175.0 225.0 350.0 600.0 800.0 kVA 16.5 22.0 33.0 54.9 78.6 Load Amps 68.8 91.6 137.5 228.8 343.2 Fuse Size 80.0 110.0 175.0 300.0 400.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 253 Dry Type Distribution Transformers Selection Tables: Single Phase Table 2: Using Group 2 (120 x 240 V Primary, 16/32 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS20B150 HS20B250 HS20F500B HS20F750B HS20F1B BOOSTING 95 120 1 B1 kVA 0.6 0.9 1.9 2.8 3.8 Load Amps 4.7 7.8 15.6 23.4 31.2 50.0 Fuse Size 106 120 1 A1 10.0 15.0 25.0 40.0 kVA 1.1 1.9 3.7 5.6 7.5 Load Amps 9.4 15.6 31.2 46.8 62.5 15.0 25.0 45.0 70.0 90.0 1.0 1.6 3.2 4.9 6.5 Fuse Size kVA 183 208 1 D1 Load Amps Fuse Size 195 208 1 C1 236 1 D1 1 C1 3.2 6.5 9.7 13.0 15.6 31.2 46.8 62.5 15.0 25.0 45.0 70.0 90.0 kVA 1.1 1.8 3.7 5.5 7.4 Load Amps 4.7 7.8 15.6 23.4 31.2 10.0 15.0 25.0 40.0 50.0 2.3 3.7 7.5 11.2 15.0 Load Amps kVA 272 1 D1 31.2 45.0 2.0 Fuse Size 240 ** 23.4 35.0 9.4 Fuse Size 240 15.6 25.0 kVA kVA 225 7.8 15.0 Load Amps Fuse Size 208 4.7 10.0 Load Amps Fuse Size 9.4 15.6 31.2 46.8 62.5 15.0 25.0 45.0 70.0 90.0 1.3 2.1 4.2 6.4 8.5 4.7 7.8 15.6 23.4 31.2 10.0 15.0 25.0 35.0 45.0 BUCKING kVA 136 ** 152 ** 120 120 1 1 A2 B2 1.3 2.1 4.2 6.4 8.5 Load Amps 10.6 17.7 35.4 53.2 70.8 Fuse Size 80.0 15.0 20.0 40.0 60.0 kVA 0.7 1.2 2.4 3.6 4.7 Load Amps 6.0 9.9 19.8 29.6 39.5 10.0 15.0 20.0 30.0 40.0 1.1 1.8 3.7 5.5 7.4 Fuse Size kVA 236 208 1 D2 Load Amps 5.3 8.9 17.7 26.5 35.4 Fuse Size 6.0 15.0 20.0 30.0 40.0 kVA 256 ** 272 ** 240 240 1 1 C2 D2 2.4 4.0 8.0 12.0 16.0 Load Amps 10.0 16.6 33.3 50.0 66.7 Fuse Size 15.0 20.0 40.0 60.0 80.0 kVA 1.3 2.1 4.2 6.4 8.5 Load Amps 5.3 8.8 17.7 26.5 35.4 10.0 15.0 20.0 30.0 40.0 Fuse Size * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 254 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Single Phase Table 2: Using Group 2 (120 x 240 V Primary, 16/32 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS20F1.5A HS20F2A HS20F3A HS20F5A HS20F7.5A BOOSTING kVA 95 106 120 120 1 1 B1 A1 195 208 1 1 D1 C1 225 240 1 1 D1 C1 62.5 93.7 156.0 234.0 100.0 150.0 250.0 400.0 kVA 11.2 15.0 22.5 37.4 56.2 Load Amps 93.7 125.0 187.5 312.0 468.0 150.0 200.0 300.0 450.0 700.0 Load Amps 272 1 D1 9.7 13.0 19.5 32.4 48.6 46.8 62.5 93.7 156.0 234.0 Fuse Size 70.0 90.0 150.0 225.0 350.0 kVA 19.5 26.0 39.0 64.9 97.3 Load Amps 93.7 125.0 187.5 312.0 468.0 125.0 175.0 250.0 450.0 700.0 11.0 14.7 22.0 36.8 55.2 Load Amps 46.8 62.5 93.7 156.0 234.0 Fuse Size 70.0 90.0 150.0 225.0 350.0 kVA 22.5 30.0 45.0 74.8 112.3 Load Amps 93.7 125.0 187.5 312.0 468.0 700.0 Fuse Size 240 ** 28.0 46.8 kVA 236 18.7 80.0 Fuse Size 208 11.2 Load Amps kVA 208 7.5 Fuse Size Fuse Size 183 5.6 125.0 175.0 250.0 450.0 kVA 12.7 17.0 25.5 42.4 63.6 Load Amps 46.8 62.5 93.7 156.0 234.0 Fuse Size 70.0 90.0 150.0 225.0 350.0 17.0 25.5 42.4 63.6 BUCKING kVA 136 ** 120 1 A2 Load Amps 106.2 141.7 212.5 353.6 530.4 Fuse Size 125.0 175.0 250.0 400.0 600.0 7.1 9.5 14.3 23.7 35.6 kVA 152 ** 236 256 ** 120 208 240 1 1 1 B2 D2 C2 Load Amps 59.4 79.2 118.8 197.6 296.4 Fuse Size 60.0 80.0 125.0 200.0 300.0 kVA 11.1 14.8 22.1 36.8 55.2 Load Amps 53.2 70.9 106.4 177.0 265.5 Fuse Size 60.0 80.0 125.0 200.0 300.0 kVA 24.0 32.0 48.0 79.9 119.8 Load Amps 99.9 133.3 200.0 332.8 499.2 125.0 175.0 250.0 400.0 600.0 12.8 17.0 25.5 42.4 63.6 Fuse Size kVA 272 ** 240 1 D2 12.7 Load Amps 53.2 70.8 106.3 176.8 265.2 Fuse Size 60.0 80.0 125.0 200.0 300.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 255 Dry Type Distribution Transformers Selection Tables: Single Phase Table 3: Using Group 3 (240 x 480 V Primary, 24/48 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS22B150 HS22B250 HS22F500B HS22F750B HS22F1B 1.25 2.50 3.74 4.99 BOOSTING 200 230 ** 240 277 1 1 B1 B1 kVA 0.75 Load Amps 3.10 5.20 10.40 15.60 20.80 Fuse Size 6.00 10.00 15.00 20.00 30.00 kVA 0.87 1.44 2.88 4.22 5.76 Load Amps 3.10 5.20 10.40 15.60 20.80 10.00 15.00 20.00 25.00 35.00 kVA 1.20 1.98 3.95 5.93 7.90 Load Amps 3.10 5.20 10.40 15.60 20.80 Fuse Size 6.00 10.00 15.00 20.00 30.00 kVA 2.40 3.95 7.90 11.86 15.81 Load Amps 6.30 10.40 20.80 31.20 41.60 Fuse Size 346 362 380 380 1 1 D1 C1 Fuse Size 378 436 458 ** 416 480 480 1 1 1 D1 D1 C1 10.00 15.00 30.00 40.00 60.00 kVA 1.30 2.16 4.33 6.49 8.65 Load Amps 3.10 5.20 10.40 15.60 20.80 Fuse Size 6.00 10.00 15.00 25.00 30.00 kVA 1.50 2.50 4.99 7.49 9.98 Load Amps 3.10 5.20 10.40 15.60 20.80 Fuse Size 6.00 10.00 15.00 25.00 30.00 kVA 3.00 4.99 9.98 14.98 19.97 Load Amps 6.30 10.40 20.80 31.20 41.60 15.00 15.00 30.00 45.00 60.00 Fuse Size BUCKING 277 ** 398 230 380 1 1 B2 C2 kVA 0.86 1.44 2.88 4.33 5.76 Load Amps 3.80 6.26 12.53 18.79 25.05 Fuse Size 6.00 10.00 15.00 20.00 30.00 kVA 2.50 4.14 8.28 12.40 16.60 Load Amps 6.50 10.89 21.79 32.70 43.60 10.00 15.00 30.00 40.00 60.00 kVA 1.30 2.18 4.35 6.52 8.69 Load Amps 3.40 5.72 11.40 17.20 22.90 Fuse Size 6.00 10.00 15.00 20.00 30.00 kVA 3.10 5.24 10.50 15.70 21.00 Load Amps 6.60 10.40 21.80 32.80 43.70 Fuse Size 418 ** 504 ** 380 480 1 1 D2 C2 Fuse Size 528 ** 480 1 D2 15.00 15.00 30.00 45.00 60.00 kVA 1.65 2.75 5.49 8.24 11.00 Load Amps 3.40 5.72 11.44 17.16 22.88 Fuse Size 6.00 10.00 15.00 20.00 30.00 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 256 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Single Phase Table 3: Using Group 3 (240 x 480 V Primary, 24/48 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS22F1.5A HS22F2A HS22F3A HS22F5A HS22F7.5A 9.98 15.0 24.96 37.44 BOOSTING kVA 200 230 ** 240 277 1 1 B1 B1 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 90.0 150.0 225.0 kVA 8.64 11.52 17.31 28.81 43.21 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 100.0 175.0 250.0 11.86 15.81 23.75 39.52 59.28 31.2 41.6 62.5 104.0 156.0 kVA 346 380 1 D1 Load Amps Fuse Size kVA 362 380 1 C1 Load Amps Fuse Size kVA 378 416 1 D1 458 ** 480 480 1 1 D1 C1 45.0 60.0 90.0 150.0 225.0 23.75 31.65 47.5 79.04 118.56 62.5 83.3 125 208 312.0 90.0 110.0 175.0 300.0 450.0 12.98 17.31 26.0 43.26 64.9 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 60.0 90.0 150.0 225.0 kVA 436 7.49 14.98 19.97 30.0 49.92 74.88 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 45.0 60.0 90.0 150.0 225.0 kVA 30.0 39.98 60.0 99.84 149.76 Load Amps 62.5 83.3 125.0 208.0 312.0 Fuse Size 90.0 110.0 175.0 300.0 450.0 kVA 8.64 11.5 17.3 28.8 43.2 Load Amps 37.6 50.1 75.3 125.3 187.9 BUCKING 277 ** 398 418 * 504 ** 528 ** 230 380 380 480 480 1 1 1 1 1 B2 C2 D2 C2 D2 Fuse Size 40.0 60.0 80.0 150.0 200.0 kVA 24.8 33.1 49.8 82.8 124.2 Load Amps 65.4 87.1 130.9 217.9 326.8 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 13.0 17.4 26.1 43.5 65.2 Load Amps 34.3 45.8 68.8 114.4 171.6 Fuse Size 40.0 60.0 80.0 150.0 200.0 kVA 31.4 41.9 63.0 104.8 157.2 Load Amps 65.5 87.4 131.3 218.4 327.6 Fuse Size 90.0 110.0 175.0 300.0 450.0 kVA 16.5 22.0 33.0 54.9 82.4 Load Amps 34.3 45.8 68.8 114.4 171.6 Fuse Size 40.0 60.0 80.0 150.0 200.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 257 Dry Type Distribution Transformers Selection Tables: Three Phase Table 4: Using Group 1 (120 x 240 V Primary, 12/24 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS19B50 HS19B100 HS19B150 HS19B250 HS19F500B HS19F750B HS19F1B BOOSTING kVA 188 198 208 208 2 2 F1 E1 0.749 1.5 2.25 3.75 7.51 11.3 15.0 2.08 4.16 6.25 10.4 20.8 31.25 41.6 Fuse Size 6.0 10.0 15.0 15.0 30.0 45.0 60.0 kVA 1.5 3.0 4.5 7.51 15.0 22.5 30.0 4.16 8.32 12.5 20.8 41.6 62.5 83.3 6.0 15.0 25.0 30.0 60.0 90.0 110.0 0.825 1.65 2.48 4.13 8.26 12.4 16.5 2.08 4.16 6.25 10.4 20.8 31.25 41.6 6.0 10.0 15.0 15.0 30.0 45.0 60.0 Load Amps Load Amps Fuse Size kVA 208 229 2 F1 Load Amps Fuse Size 208 228 ** 229 240 3 2 J1 E1 kVA 1.65 3.3 4.96 8.26 16.5 24.8 33.1 Load Amps 4.16 8.32 12.5 20.8 41.6 62.5 83.3 Fuse Size 10.0 15.0 20.0 30.0 60.0 90.0 125.0 kVA 1.73 3.46 5.2 8.68 17.3 26 34.6 Load Amps 4.16 8.32 12.5 20.8 41.6 62.5 83.3 Fuse Size 416 436 3 L1 6.0 15.0 20.0 30.0 60.0 90.0 110.0 kVA 3.15 6.29 9.44 15.8 31.5 47.2 62.9 Load Amps 4.16 8.32 12.5 20.8 41.6 62.5 83.3 6.0 15.0 20.0 30.0 60.0 90.0 110.0 kVA 1.65 3.31 4.96 8.27 16.5 24.8 33 Load Amps 2.08 4.16 6.25 10.4 20.8 31.25 41.6 3.0 6.0 10.0 15.0 30.0 45.0 60.0 Fuse Size 416 458 3 M1 Fuse Size BUCKING 218 208 2 E2 kVA 1.57 3.14 4.73 7.85 15.7 23.6 31.4 Load Amps 4.36 8.72 13.1 21.8 43.6 65.5 87.2 Fuse Size 10.0 15.0 20.0 30.0 60.0 80.0 110.0 0.824 1.65 2.48 4.12 8.25 12.4 16.5 2.29 4.58 6.88 11.4 22.9 34.4 45.8 6.0 10.0 15.0 15.0 30.0 40.0 60.0 kVA 1.82 3.63 5.46 9.08 18.2 27.3 36.3 Load Amps 4.37 8.74 13.1 21.8 43.7 65.6 87.4 Fuse Size 6.00 10.00 15.00 30.00 60.00 80.00 110.00 0.951 1.9 2.86 4.76 9.51 14.3 19.00 2.29 4.58 6.88 11.44 22.9 34.4 45.8 Fuse Size 6.0 6.0 10.0 15.0 30.0 40.0 60.0 kVA 1.5 3.0 4.5 7.49 15.0 22.5 30.0 2.29 4.58 6.88 11.44 22.9 34.4 45.8 6.0 6.0 10.0 15.0 30.0 40.0 60.0 kVA 229 208 2 F2 Load Amps Fuse Size 252 ** 240 2 E2 kVA 264 ** 418 240 378 2 3 F2 M2 Load Amps Load Amps Fuse Size * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 258 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Three Phase Table 4: Using Group 1 (120 x 240 V Primary, 12/24 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS19F1.5A HS19F2A HS19F3A HS19F5A HS19F7.5A 30.0 45.0 75.1 112.5 BOOSTING 188 198 208 208 208 208 229 229 2 2 2 3 F1 E1 F1 J1 kVA 22.5 Load Amps 62.5 83.3 125.0 208.3 312.5 Fuse Size 90.0 125.0 175.0 300.0 450.0 kVA 45.0 60.0 90.1 150.1 225.2 Load Amps 125.0 166.6 250.0 416.6 625.0 Fuse Size 175.0 225.0 350.0 600.0 1000.0 kVA 24.8 33.1 49.6 82.6 123.9 Load Amps 62.5 83.3 125.0 208.3 312.5 Fuse Size 90.0 125.0 175.0 300.0 450.0 kVA 49.6 66.1 99.2 165.3 247.9 Load Amps 125.0 166.6 250.0 416.6 625.0 Fuse Size 175.0 250.0 350.0 600.0 1000.0 52.0 69.3 103.9 173.2 259.8 Load Amps 125.0 166.6 250.0 416.6 625.0 Fuse Size 175.0 250.0 350.0 600.0 1000.0 472.0 kVA 228 ** 240 2 E1 kVA 416 416 436 458 3 3 L1 M1 94.4 125.8 188.79 314.6 Load Amps 125.0 166.6 250.0 416.6 625.0 Fuse Size 175.0 250.0 350.0 600.0 1000.0 kVA 49.6 66.1 99.2 165.3 247.9 Load Amps 62.5 83.3 125.0 208.3 312.5 Fuse Size 90.0 125.0 175.0 300.0 450.0 BUCKING kVA 218 229 208 208 2 2 E2 F2 47.2 62.7 94.4 157.3 236.0 Load Amps 131.0 174.0 262.0 436.6 655.0 Fuse Size 175.0 225.0 350.0 600.0 800.0 kVA 24.8 33.0 49.6 82.5 123.9 Load Amps 68.8 91.6 137.6 229.0 344.1 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 252 ** 264 ** 418 240 240 378 2 2 3 E2 F2 M2 54.6 72.5 109.1 181.8 272.8 Load Amps 131.3 174.3 262.5 437.4 656.3 Fuse Size 175.0 225.0 350.0 600.0 800.0 kVA 28.6 38.0 57.2 95.1 142.9 Load Amps 68.8 91.5 137.5 228.8 343.8 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 45.0 59.9 90.1 149.9 225.2 Load Amps 68.8 91.6 137.6 228.9 343.9 Fuse Size 80.0 110.0 175.0 300.0 400.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 259 Dry Type Distribution Transformers Selection Tables: Three Phase Table 5: Using Group 2 (120 x 240 V Primary, 16/32 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS20B150 HS20B250 HS20F500B HS20F750B HS20F1B BOOSTING 184 195 208 208 208 208 236 236 2 2 2 3 F1 E1 F1 J1 kVA 1.69 2.81 5.63 8.44 11.3 Load Amps 4.69 7.8 15.6 23.4 31.2 Fuse Size 10.0 15.0 25.0 35.0 45.0 kVA 3.38 5.63 11.3 16.9 22.5 Load Amps 9.38 15.6 31.2 46.9 62.5 Fuse Size 15.0 25.0 45.0 70.0 90.0 kVA 1.92 3.19 6.39 9.58 12.8 Load Amps 4.69 7.8 15.6 23.4 31.2 Fuse Size 10.0 15.0 25.0 35.0 45.0 kVA 3.83 6.38 12.8 19.2 25.6 Load Amps 9.38 15.6 31.2 46.9 62.5 Fuse Size 15.0 25.0 45.0 70.0 90.0 3.9 6.5 13.0 19.5 26.0 Load Amps 9.38 15.6 31.2 46.9 62.5 Fuse Size 15.0 25.0 45.0 70.0 90.0 7.2 12.0 24.0 36.0 48.0 kVA 225 240 2 E1 kVA 416 416 443 471 3 3 L1 M1 Load Amps 9.38 15.6 31.2 46.9 62.5 Fuse Size 15.0 25.0 45.0 70.0 90.0 kVA 3.83 6.37 12.8 19.1 25.5 Load Amps 4.69 7.8 15.6 23.4 31.2 Fuse Size 10.0 15.0 25.0 35.0 45.0 BUCKING 222 236 256 ** 272 ** 432 208 208 240 240 380 2 2 2 2 3 E2 F2 E2 F2 M2 kVA 3.61 6.0 12.0 18.0 24.0 Load Amps 10.0 16.6 33.3 50.1 66.7 Fuse Size 15.0 20.0 40.0 60.0 80.0 kVA 1.92 3.19 6.38 9.56 12.8 Load Amps 5.32 8.85 17.7 26.5 35.4 Fuse Size 10.0 10.0 20.0 30.0 40.0 kVA 4.16 6.92 13.8 20.8 27.7 Load Amps 10.1 16.6 33.3 50.0 66.7 Fuse Size 15.0 20.0 40.0 60.0 80.0 kVA 2.21 3.67 7.35 11.0 14.7 Load Amps 5.32 8.84 17.7 26.5 35.4 Fuse Size 10.0 15.0 20.0 30.0 40.0 kVA 3.51 5.84 11.7 17.5 23.3 Load Amps 5.33 8.87 17.7 26.6 35.5 Fuse Size 10.0 10.0 20.0 30.0 40.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 260 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Three Phase Table 5: Using Group 2 (120 x 240 V Primary, 16/32 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS20F1.5A HS20F2A HS20F3A HS20F5A HS20F7.5A BOOSTING 184 195 208 208 2 2 F1 E1 kVA 16.9 22.5 33.8 56.3 84.4 Load Amps 46.9 62.5 93.8 156.0 234.0 Fuse Size 60.0 90.0 150.0 225.0 350.0 kVA 33.8 45.0 67.6 112.6 168.9 Load Amps Fuse Size kVA 208 208 236 236 2 3 F1 J1 240 2 E1 3 L1 471 3 M1 468.0 700.0 19.2 25.6 38.2 63.9 95.8 46.9 62.5 93.7 156.0 234.0 90.0 150.0 225.0 350.0 kVA 38.2 51.1 76.6 127.7 191.6 Load Amps 93.7 125.0 187.5 312.0 468.0 150.0 200.0 300.0 450.0 700.0 kVA 71.9 52.0 77.9 129.9 194.0 Load Amps 93.7 125.0 187.5 312.0 468.0 125.0 175.0 250.0 450.0 700.0 71.9 95.9 143.9 239.8 359.7 Load Amps Fuse Size 416 312.0 450.0 70.0 Fuse Size 443 187.5 250.0 Load Amps kVA 416 125.0 175.0 Fuse Size Fuse Size 225 93.7 125.0 93.7 125 187.5 312.0 468.0 125.0 175.0 250.0 450.0 700.0 kVA 38.2 51.0 76.5 127.5 191.2 Load Amps 46.9 62.5 93.8 156.0 234.0 Fuse Size 70.0 90.0 150.0 225.0 350.0 BUCKING kVA 222 236 256 ** 208 208 240 2 2 2 E2 F2 E2 36.0 48.1 72.1 120.0 179.9 Load Amps 100.0 133.4 200.1 333.0 499.5 Fuse Size 600.0 125.0 175.0 250.0 400.0 kVA 19.2 25.5 38.8 63.8 95.6 Load Amps 53.2 70.9 106.4 177.0 265.5 Fuse Size 60.0 80.0 125.0 200.0 300.0 kVA 41.5 55.4 83.1 138.3 207.5 Load Amps Fuse Size 272 ** 432 240 380 2 3 F2 M2 99.9 133.3 200.0 332.8 499.2 125.0 175.0 250.0 400.0 600.0 kVA 22.1 29.4 44.2 73.5 110.2 Load Amps 53.2 70.8 106.3 176.8 265.2 Fuse Size 60.0 80.0 125.0 200.0 300.0 kVA 35.1 46.8 70.2 116.7 175.1 Load Amps 53.3 71.1 106.6 177.3 266.0 Fuse Size 60.0 80.0 125.0 200.0 300.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 261 Dry Type Distribution Transformers Selection Tables: Three Phase Table 6: Using Group 3 (240 x 480 V Primary, 24/48 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS22B150 HS22B250 HS22F500B HS22F750B HS22F1B BOOSTING 173 208 2 G1 kVA 1.12 Load Amps Fuse Size kVA 200 240 2 G1 346 380 416 2 3 E1 K1 436 468 480 492 3 2 2 K1 F1 E1 7.5 3.12 5.2 6.0 10.0 10.4 15.6 20.8 20.0 25.0 35.0 2.16 4.33 6.5 8.66 5.2 10.4 15.6 20.8 6.0 10.0 20.0 25.0 35.0 kVA 3.91 6.52 13 19.6 26.1 Load Amps 6.24 10.4 20.8 31.2 41.6 Fuse Size 10.0 15.0 30.0 45.0 60.0 kVA 2.25 3.75 7.5 11.3 15.0 Load Amps 3.12 5.2 10.4 15.6 20.8 6.0 10.0 20.0 25.0 35.0 2.59 4.33 8.65 13.0 17.3 kVA 480 5.63 1.3 Fuse Size 400 3.75 3.12 Load Amps Fuse Size 362 1.88 Load Amps 3.12 5.2 10.4 15.6 20.8 Fuse Size 10.0 15.0 20.0 25.0 35.0 kVA 2.59 4.33 8.65 13 17.3 Load Amps 3.12 5.2 10.4 15.6 20.8 Fuse Size 6.0 10.0 15.0 25.0 30.0 kVA 5.2 8.66 17.3 26.0 34.6 Load Amps 6.24 10.4 20.8 31.2 41.6 Fuse Size 15.0 15.0 30.0 45.0 60.0 kVA 1.35 2.25 4.5 6.75 9.01 Load Amps 3.75 6.25 12.5 18.7 25.0 6.0 10.0 15.0 20.0 30.0 kVA 2.47 4.12 8.23 12.3 16.5 Load Amps 3.75 6.25 12.5 18.8 25.0 6.0 10.0 15.0 20.0 30.0 BUCKING 250 208 2 G2 Fuse Size 457 380 3 K2 Fuse Size kVA 499 416 3 K2 Load Amps Fuse Size 504 ** 528 ** 480 480 2 2 E2 F2 2.7 4.49 8.99 13.5 18.0 3.74 6.24 12.5 18.7 24.9 6.0 10.0 15.0 20.0 30.0 kVA 5.45 9.08 18.2 27.2 36.3 Load Amps 6.56 10.9 21.8 32.8 43.7 Fuse Size 15.0 15.0 30.0 40.0 60.0 kVA 2.85 4.76 9.51 14.3 19.0 Load Amps 3.43 5.72 11.4 17.2 22.9 6.0 10.0 15.0 20.0 30.0 Fuse Size * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). 262 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Selection Tables: Three Phase Table 6: Using Group 3 (240 x 480 V Primary, 24/48 V Secondary) Transformers Input Voltage Output Voltage Quantity Req'd Connection Diagram * Application Data Catalog Number HS22F1.5A HS22F2A HS22F3A HS22F5A HS22F7.5A 22.5 37.5 56.3 BOOSTING kVA 173 200 362 346 400 436 468 208 240 380 416 480 480 492 2 2 2 3 3 2 2 G1 G1 E1 K1 K1 F1 E1 11.3 15 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 100.0 175.0 250.0 kVA 13.0 17.3 26.0 43.3 65.0 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 100.0 175.0 250.0 kVA 39.1 52.2 78.4 130.4 195.6 Load Amps 62.4 83.2 125 208.0 312.0 Fuse Size 90.0 125.0 175.0 300.0 450.0 kVA 22.5 30.0 45.0 75.1 112.6 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 100.0 175.0 250.0 kVA 26.0 34.6 52.0 86.6 129.9 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 50.0 70.0 100.0 175.0 250.0 kVA 26.0 34.6 52.0 86.6 129.9 Load Amps 31.2 41.6 62.5 104.0 156.0 Fuse Size 45.0 60.0 90.0 150.0 225.0 kVA 52.0 69.3 103.9 173.2 259.8 Load Amps 62.4 83.2 125.0 208.0 312.0 Fuse Size 90.0 110.0 175.0 300.0 450.0 18.0 27.1 45.0 67.5 BUCKING kVA 250 457 499 504 ** 528 ** 208 380 416 480 480 2 3 3 2 2 G2 K2 K2 E2 F2 13.5 Load Amps 37.5 50.0 75.1 125.0 187.5 Fuse Size 40.0 60.0 80.0 150.0 200.0 kVA 24.7 32.9 49.5 82.3 123.5 Load Amps 37.5 50.0 75.2 125.1 187.6 Fuse Size 40.0 60.0 80.0 150.0 200.0 kVA 27.0 36.0 54.0 89.9 134.8 Load Amps 37.4 49.9 75.0 124.7 187.1 Fuse Size 40.0 60.0 80.0 150.0 200.0 kVA 54.5 72.6 109.1 181.6 272.4 Load Amps 65.5 87.4 131.3 218.4 327.6 Fuse Size 80.0 110.0 175.0 300.0 400.0 kVA 28.5 38.0 57.2 95.1 142.7 Load Amps 34.3 45.8 68.8 114.4 171.6 Fuse Size 40.0 60.0 80.0 150.0 200.0 * For alternate electrical connection diagrams, refer to the section immediately following the selection tables. ** Shaded items are 60 Hz only (All other ratings shown are 50/60 Hz). Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 263 Dry Type Distribution Transformers Alternate Electrical Connections for Buck-Boost Applications X2 X4 X2 X4 X3 X1 X3 X4 X1 X3 X2 H2 H4 X1 H4 Output Output H2 H3 H4 Input Output Input H2 Input H1 H3 H1 Diagram A1 - Boosting X2 H1 H3 Diagram B1 - Boosting Diagram C1 - Boosting X4 X2 X4 X3 X1 X3 X4 Input X1 X3 H2 H4 H4 X2 Input X1 Output Output H2 H3 H4 Input H2 Output H1 H3 Diagram A2 - Bucking H1 H3 Diagram B2 - Bucking H1 Diagram C2 - Bucking The O symbol shown on these connection diagrams indicates where fuses or breakers should be field installed for line to neutral applications. For line to line applications, fuses or breakers should be installed on both lines. Application Note: On all auto-wye connections, the source neutral must be present and connected to the transformer bank. If source neutral is not present, do not use an auto-wye connection. 264 Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Alternate Electrical Connections for Buck-Boost Applications OPEN DELTA X4 INPUT 3 2 1 X3 OPEN DELTA OUTPUT 1 2 3 INPUT 3 2 1 OUTPUT 1 2 3 X2 X2 X4 X1 X3 X4 X1 H4 H3 H3 Input H2 H2 X3 X F R M R H4 Output H4 X F R M R H3 A X2 X1 A H2 H1 H1 H1 H1 H1 H2 Diagram D1 - Boosting X F R M R H2 H3 X1 H4 X3 X2 X4 H3 H4 X1 B X2 X4 Diagram F1 - Boosting OPEN DELTA INPUT 3 2 1 B X3 Diagram E1 - Boosting X4 X F R M R OPEN DELTA OUTPUT 3 2 1 INPUT 3 2 1 OUTPUT 3 2 1 X3 X2 X2 X4 X1 X1 X3 X4 H4 H4 Output H3 H3 Input X3 X F R M R H2 A H2 H4 X F R M R H3 A X2 X1 H2 H1 H1 H1 H1 H1 H2 Diagram D2 - Bucking H2 H3 H4 X1 X3 X2 X4 X F R M R B H3 H4 X1 X F R M R X2 X3 B X4 Diagram E2 - Bucking Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Diagram F2 - Bucking 265 Dry Type Distribution Transformers Alternate Electrical Connections for Buck-Boost Applications OPEN DELTA OPEN DELTA INPUT 1 2 3 INPUT 1 2 3 OUTPUT 1 2 3 OUTPUT 1 2 3 INPUT 2 3 1 X2 AUTO-WYE CONNECTION N 1 X4 X2 X4 X1 X3 H2 H4 H1 H3 OUTPUT 2 3 N X4 X F R M R X3 X2 X1 H4 H2 H1 H3 H1 H3 H2 H4 X1 H2 X F R M R X3 H4 A A X F R M R X1 X2 X2 X4 H1 H3 X1 X3 H1 H3 H2 H4 H1 H3 H2 H4 X2 X4 X1 X3 X1 X3 H2 H4 H1 H3 B B X4 X2 A X F R M R B X F R M R X3 X F R M R X4 X F R M R C Diagram H1 - Boosting Diagram G1 - Boosting OPEN DELTA OPEN DELTA INPUT 1 2 3 Diagram J1 - Boosting INPUT 1 2 3 OUTPUT 1 2 3 OUTPUT 1 2 3 X2 1 X4 X4 X F R M R X3 X2 X1 H2 H4 H1 H3 H1 H3 H2 H4 X1 X2 X1 X3 H2 H4 A A X F R M R X F R M R H1 H3 H1 H3 H2 X1 H4 X3 X F R M R X3 INPUT 2 3 AUTO-WYE CONNECTION 1 N X2 X4 X1 X3 H2 H4 H1 H3 X2 X4 X1 X3 H2 H4 H1 H3 X2 X4 X1 X3 H2 H4 H1 H3 OUTPUT 2 3 N B B X4 X2 X4 X F R M R A X F R M R B X F R M R C Diagram G2 - Bucking 266 Diagram H2 - Bucking Diagram J2 - Bucking Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Dry Type Distribution Transformers Alternate Electrical Connections for Buck-Boost Applications INPUT 2 3 N 1 1 OUTPUT 2 3 N H2 H1 H3 H1 H3 OUTPUT 2 3 N INPUT 2 3 N 1 X1 X F R M R X4 X3 H4 H3 H2 X F R M R X2 X1 H2 X1 H4 H1 H3 X3 X F R M R X3 X2 X1 H4 H3 H2 H1 B B X4 H3 H2 X F R M R X3 X2 X1 H4 X F R M R X4 X3 H4 C A X4 H1 X2 X1 X F R M R H1 X F R M R X4 H3 H2 X F R M R X3 X2 OUTPUT 2 3 N X3 X2 X1 H4 H3 H2 A H4 B X4 1 X4 X2 H1 X3 X2 H2 1 A X4 X1 H4 INPUT 2 3 N 1 X F R M R X4 X3 X2 X1 H4 AUTO-WYE CONNECTION AUTO-WYE CONNECTION AUTO-WYE CONNECTION H3 H2 H1 C C H1 Diagram K1 - Boosting Diagram L1 - Boosting AUTO-WYE CONNECTION 1 INPUT 2 3 N OUTPUT 2 3 N X4 X3 X2 X1 1 X F R M R INPUT 2 3 N 1 X2 X4 X1 X3 H3 H2 H4 H3 X4 X3 X2 X1 H2 H4 H1 H3 X4 H2 H1 X3 X2 X1 H4 H3 OUTPUT 2 3 N H4 A H1 AUTO-WYE CONNECTION AUTO-WYE CONNECTION 1 H2 Diagram M1 - Boosting 1 X F R M R INPUT 2 3 N 1 X4 A X2 X4 B X F R M R C X F R M R X4 X4 X3 H4 H3 H2 X F R M R C X3 X2 X1 H4 H3 H2 H1 B X2 X1 X3 X2 X1 H4 H3 H2 X F R M R A H1 H1 X F R M R OUTPUT 2 3 N X4 X3 X2 X1 H4 H3 H2 H1 X F R M R B X F R M R C H1 Diagram K2 - Bucking Diagram L2 - Bucking Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017 Diagram M2 - Bucking 267 Dry Type Distribution Transformers Application Note Application Limitations with Buck-Boost Transformers What is a Buck-Boost transformer and why is it used? 1. Isolation transformers have separate primary and secondary windings, electrically insulated and isolated from one another. With a relatively high voltage primary (typically 120, 240 or 480 Volts) and a relatively low voltage secondary (typically 12, 16, 24, 32 or 48 Volts), buck-boost transformers are designed to be field connected as autotransformers. These are transformers with one continuous winding, a portion of which is jointly shared between the input and the output. No electrical isolation is present in an autotransformer. A Buck-Boost transformer cannot be used to develop a three phase, four wire wye circuit from a three phase, three wire delta circuit. A delta to wye connection does not supply enough current carrying capability to provide for unbalanced currents flowing in the neutral wire of the four wire circuit. The neutral created is not stable and under load will not deliver desired line to neutral voltages. This connection would also be in violation of the National Electric Code, Article 210.9. 2. Buck-Boost transformers cannot be used in a closed delta connection. A closed delta requires more kVA capacity than a wye or an open delta connection, plus phase shifting comes into play on the output side. 3. Buck-Boost transformers should not be used to correct for voltage drop on a long circuit run where the load fluctuates. Voltage drop varies with the load and buck-boost transformers are connected for a specific voltage change. If a buck-boost transformer was used to correct voltage drop during peak loading conditions, high voltages may result under light load conditions. This could be equally detrimental to the load and possibly pose safety hazards. 4. Buck-Boost transformers cannot be used to create a 240/120 Volt, single phase service from a 208Y/120 Volt three phase supply. Two problems that would occur: A. Two neutrals would exist on the same circuit. Since neutrals must be grounded according to the National Electric Code, a short circuit would be created. B. Unbalanced line to output neutral voltages would be created; one line would read 120 Volts, the other 130+ Volts. 268 Buck-Boost transformers have two major uses: 1. When field connected as an autotransformer, they can be used to Buck (lower) or Boost (raise) available line voltage in the range of 5 to 27% and at a kVA rating many times that listed on the transformer nameplate. 2. When left as an isolation transformer, they can be used to supply power to low voltage circuits at the nameplate rating listed. The importance of altering available line voltage. Electrical equipment is designed to operate at maximum efficiency at a specific standard supply voltage. Your voltage may not be at the standard supply voltage level. Causes can be proximity to a large utility transformer, losses in the line voltage due to loads on that circuit, or a difference between the standard supply voltage available and the standard supply voltage needed to run the equipment. Normally the problem is having low voltage available. Low voltage on a circuit, even as little as 5% lower can cause a decrease in incandescent light output, and a decrease in resistive heat output. With motors low voltage can cause a decrease in motor torque, an increase in motor amperage requirements, an increase in motor temperature and decrease in motor life expectancy. Visit our website at www.emerson.com or contact Technical Services at (800) 377-4384 with any questions. (c) January 2017