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40 HP Buck-Boost Transformer, 400V to 427V, Three Phase (3-PH), Wye
by Sanzo Sales · Part # TX-BB-400Y-427Y.247-40HP
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Voltage, phase, and connection match. Capacity differs, so review any lower-capacity warning.
Lower-capacity option — confirmation required
40 HP selection three-phase wye buck-boost transformer for 400 V to 427 V nominal step-up voltage correction, rated for up to 44.83 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.
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TX-BB-400Y-427Y.247-40HP
0 currently in stock
- 36 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.
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Specifications
| Brand | Sanzo Sales |
| Frequency | 50/60 Hz |
| Temperature Rise | 115°C |
| Insulation | 180°C |
| Configuration | Resin-Encapsulated |
| Winding Material | Aluminum |
| Weatherproof Rating | NEMA 3R |
| Enclosure Material | Steel |
| Finish Color | ANSI 70 Light Grey |
| Certification Listing | cETLus |
| Transformer Type | Buck/Boost |
| Phase | Three Phase (3-PH), Wye |
| Part # | TX-BB-400Y-427Y.247-40HP |
| Capacity | 33.12 kVA kVA |
| Primary Voltage | 400V |
| Secondary Voltage | 427V |
| Primary Amperage | 47.819 A |
| Secondary Amperage | 44.83 A |
| Maximum Primary OCP | Determine for the installed circuit |
| Catalog Selection | 40 HP |
| Secondary Line-to-Neutral Voltage | 247V |
| Dimensions (W×H×D) | 5.43 × 10.08 × 4.49 in |
| Weight | 66 lb |
Product Description
The TX-BB-400Y-427Y.247-40HP is a three-phase wye step-up buck-boost transformer for applications with a nominal 400 V supply and equipment requiring 427 V. It raises the supply voltage to help match the equipment's operating range. The finished-product rating is 44.83 A continuous output, with 33.12 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. The HP designation is a selection label, not a universal compatibility guarantee. Power factor, efficiency and starting duty affect the electrical load; the stated ampere limit governs selection.
Will the output stay at exactly 427 V?
The 427 V 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 three-phase wye applications. Match the supply neutral and equipment neutral requirements to the assigned installation instructions; this product does not create a neutral. 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.