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15 kVA Step-Down Buck-Boost Transformer, 208V → 189V, 79.33A, Single Phase
$1,127.44
15 kVA single-phase buck-boost transformer for 208V to 189V nominal step-down voltage correction, rated for up to 79.33 A continuous output. Match the supply voltage, equipment voltage and load current before ordering. This autotransformer corrects voltage without electrical isolation; output varies with incoming supply conditions and load.
✔ In Stock: 1
Inventory & Inbound
1 currently in stock
- 30 more available, earliest Nov 16, 2026
Projected inbound quantities and dates are based on current purchase orders with our suppliers and are not guaranteed. We update them as suppliers confirm.
Specifications
| Brand | Sanzo Sales |
| Phase | Single Phase (1-PH), AC |
| Capacity | 15 kVA |
| Primary Voltage | 208V |
| Primary Amperage | 72.12 A |
| Secondary Voltage | 189V |
| Secondary Amperage | 79.33 A |
| Maximum Primary OCP | 100 A maximum input fuse or nonadjustable breaker |
| Frequency | 50/60 Hz |
| Insulation | 180°C |
| Temperature Rise | 115°C |
| Transformer Type | Buck/Boost |
| Part # | TX-BB-208V-189V-15KVA |
| Configuration | Encapsulated Autotransformer |
| Primary Termination | Lead Wires & Terminal Lugs |
| Secondary Termination | Lead Wires & Terminal Lugs |
| Termination Access | 3/4" NPT |
| Winding Material | Aluminum |
| Enclosure Material | Steel |
| Finish Color | ANSI 70 Light Grey |
| Weatherproof Rating | NEMA 3R |
| Certification Listing | cETLus |
| Dimensions (W×H×D) | 7.68 × 11.02 × 6.38 in |
| Weight | 42 lb |
Product Description
The TX-BB-208V-189V-15KVA is a single-phase step-down buck-boost transformer for applications with a nominal 208V supply and equipment requiring 189V. It reduces the supply voltage to help match the equipment's operating range. The finished-product rating is 79.33 A continuous output, with 15 kVA capacity at the calculated output voltage.
Select the right voltage and capacity
Compare the equipment nameplate voltage and running current with this product's ratings. Circuit-breaker size alone does not establish the connected load. For motors, compressors or multiple loads, check starting requirements, duty cycle and the total simultaneous current with the equipment manufacturer or qualified installer.
Will the output stay at exactly 189V?
The 189V designation is the nominal application voltage. Output is not regulated and changes with incoming voltage and load. Compare the expected operating range with the equipment's permitted voltage range rather than assuming a fixed output under every condition.
Match the electrical system
This product is intended for single-phase service and does not convert single-phase power to three-phase power. Buck-boost autotransformers provide voltage correction without electrical isolation. If electrical isolation is required, select an appropriate isolation transformer instead.
Plan the installation
Use the specification sheet, dimensional drawing and installation instructions matched to this exact part number. Review mounting clearances, conductor sizing, overcurrent protection and grounding before installation. Electrical work must be performed by qualified personnel with power disconnected.
See the specifications and product documents on this page for detailed ratings and installation requirements. Need help selecting a transformer? Use the transformer sizing calculator or request a quote with your supply voltage and equipment nameplate information.