3.75 kVA Step-Up Buck-Boost Transformer (Booster), 105V → 120V, 31.25A, Single Phase
$455.56
3.75 kVA single-phase buck-boost booster that boosts 105V to 120V (14% correction) at 31.25A. Encapsulated NEMA 3R, cETLus listed. In-stock ships same business day.
✔ In Stock: 20
Inventory & Inbound
20 currently in stock
- 60 more available, earliest Jul 21, 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 | 3.75 kVA |
| Primary Voltage | 105V |
| Primary Amperage | 35.71A |
| Secondary Voltage | 120V |
| Secondary Amperage | 31.25A |
| Maximum Primary OCP | 45A |
| Frequency | 50/60 Hz |
| Insulation | 180°C |
| Temperature Rise | 115°C |
| Transformer Type | Buck/Boost |
| Part # | TX-BB-105V-120V-31.25A |
| Configuration | Encapsulated Autotransformer |
| Primary Termination | Lead Wires & Terminal Lugs |
| Secondary Termination | Lead Wires & Terminal Lugs |
| Termination Access | (6) ¾" NPT Hubs |
| Winding Material | Aluminum |
| Enclosure Material | Steel |
| Finish Color | ANSI 70 Light Grey |
| Weatherproof Rating | NEMA 3R |
| Certification Listing | cETLus |
| Dimensions (W×H×D) | 4.65 × 9.25 × 3.86 in |
| Weight | 17 lb |
Product Description
The TX-BB-105V-120V-31.25A is a 3.75 kVA single-phase buck-boost transformer that boosts a 105V supply to 120V — a 14% voltage correction — bringing 120V-rated equipment back into its proper operating range. Wired as an encapsulated booster transformer (autotransformer), it carries only the correction portion of the load, so this unit corrects a much larger connected load: up to 31.25A at 120V (3.75 kVA usable line capacity).
Resin-encapsulated in a NEMA 3R steel enclosure (ANSI 70 light grey) for indoor or outdoor mounting at the disconnect. Lead wires and terminal lugs, aluminum windings, 180°C insulation system, 115°C rise, 50/60 Hz, cETLus listed. Use two units in open-delta for three-phase delta systems, three for wye. In-stock units ship the same business day.