Finding the right transformer to convert 208V to 240V (or vice versa) at or around 30 amps is essential for HVAC systems, industrial controls, and equipment that require precise voltage matching. This guide highlights five capable solutions from reputable brands, detailing their primary/secondary ranges, applications, and key considerations. Each option is suited for systems operating in American electrical environments, ensuring safe, efficient voltage transitions while supporting critical loads.
Below is a quick reference table of the selected products, focusing on 208/240 V inputs and higher-current outputs where applicable. The table helps you compare primary features, voltages, current ranges, and intended use at a glance.
| Product | Primary/Secondary | Current Range | Type | Brand |
|---|---|---|---|---|
| 1 Phase Buck and Boost Step-Up Transformer | 208V to 240V | 30–456 A | Step-Up/Step-Down | Larson Electronics |
| 1 Phase Buck and Boost Step-Down Transformer | 240V to 208V | 26.6–60 A | Step-Down | Larson Electronics |
| 1-Phase Buck/Boost Step-Up Transformer | 208V to 240V | 23.4–70 A | Step-Up | Larson Electronics |
| 30 KVA 3-Phase Auto Transformer | 208V/240V input | 600–2080 A (depending on tap) | Auto Transformer | American Rotary |
| ANTOBLE 208/240V to 24V Transformer | 208/240V to 24V | 40 VA | Control Transformer | ANTOBLE |
1 Phase Buck and Boost Step-Up Transformer — 208V to 240V
This transformer provides a flexible 208V to 240V conversion with a broad current range, including high-current options up to 456 amps. Designed primarily for industrial or heavy-duty HVAC loads, it supports 50/60 Hz operation and can accommodate custom options tailored to specific system needs. It is ideal for applications where a precise voltage boost is required to ensure equipment runs at the correct nominal voltage. Note that safety considerations and factory-to-user handling guidance apply for transformer usage.
- 208V primary, 240V secondary
- Multiple high-current taps: 30 A, 31.2 A, 46.8 A, 62.5 A, 93.7 A, or 456 A
- 50/60 Hz compatibility
- Custom options available
1 Phase Buck and Boost Step-Down Transformer — 240V Primary, 208V Secondary
This unit steps down from 240V to 208V, supporting loads up to 60 A. It is suitable for equipment that operates at slightly lower voltage than the supply line, reducing the risk of overvoltage on sensitive components. The design emphasizes safety and compliance; however, returns are restricted for transformers, reflecting industry practice for used or custom electrical equipment. The device is compatible with standard 50/60 Hz electrical systems and is intended for controlled, labeled installations.
- 240V primary, 208V secondary
- Current options: 26.6 A, 35.4 A, or 60 A
- 50/60 Hz operation
- Custom options available on request
1-Phase Buck/Boost Step-Up Transformer — 208V to 240V, 23.4–70 A
Offering another 208V to 240V conversion option, this transformer supports loads from 23.4 A up to 70 A, covering mid-range to higher-demand equipment. It operates at 50/60 Hz and is designed for reliable service in commercial or industrial settings. The compact design makes it suitable for equipment rooms or control panels where space is a factor. As with similar products, safety guidance and disposal considerations apply for end-of-life units.
- 208V primary, 240V secondary
- Current options: 23.4 A, 40 A, 70 A
- 50/60 Hz operation
- Suitable for mid-range loads
30 KVA 3-Phase Auto Transformer
This 30 KVA multi-tap auto transformer provides several input/output configurations, including 600, 480, 400, 240, and 208V taps. Its three-phase design suits larger facilities, commercial spaces, or manufacturing environments where stable power is critical for multiple loads. This transformer is rated for high-kVA applications and is built to tolerate varying electrical conditions. Installation considerations include proper panel mounting, vibration isolation, and adherence to code requirements for three-phase equipment.
- Multi-Tap: 600, 480, 400, 240, 208V
- Three-phase, Type 3R enclosure
- High-kVA performance for demanding loads
- Suitable for commercial and industrial systems
Functional Devices TR50VA008 Transformer
Compact and versatile, the TR50VA008 transformer is designed for 480/277/240/208 to 120 Vac conversions, with a built-in circuit breaker and dual mounting hubs. It is a practical choice for circuit protection and space-limited control panels. The unit is US-made and packaged with mounting compatibility to support straightforward installation in standard electrical cabinets. It is well-suited for control circuits, sensors, and low-to-mid power loads in commercial settings.
- Input: 480/277/240/208 to 120 Vac
- Includes circuit breaker protection
- Foot and dual-threaded hub mounting
- Manufactured in the United States
ANTOBLE 0130M00138S — 208/240V to 24V Transformer
This 40 VA transformer is designed as a direct replacement for 24V furnace or HVAC control systems. It supports primary voltage of 208/240V with a 24V secondary, making it compatible with a wide range of Goodman Amana and similar brands. The unit emphasizes OEM compatibility and durability with Class 2 power capabilities. The product is appropriate for residential HVAC control circuits and other low-voltage control applications that require stable 24V output.
- Primary 208/240V, Secondary 24V
- 40 VA power rating
- Class 2 compliant, direct replacement for common furnaces
- Foot-mount installation
Buying Guide: Key Purchase Considerations And Comparisons
Choosing the right 208 to 240 V transformer with suitable current capacity involves evaluating several factors to ensure compatibility and safety. The following perspectives help buyers compare options and make informed decisions.
- Voltage compatibility: Confirm whether you need step-up or step-down, and verify the exact 208V to 240V differential (or reverse) for your equipment’s input and output tolerances.
- Current and power rating: Match the transformer’s current capacity to the load. For high-demand systems, prefer units with higher amp or kVA ratings to avoid overheating and voltage drop.
- Phase configuration: Determine whether your system is single-phase or three-phase. Three-phase auto transformers provide broader tap options for larger installations, while single-phase units suit residential or small commercial equipment.
- Load type: Consider whether you need a pure voltage transformer or an autotransformer. Autotransformers are efficient for large step changes but must be evaluated for isolation needs.
- Install environment: Note enclosure type, mounting method, and ambient conditions. Some models include rugged housings or dedicated mounting features for control panels and electrical cabinets.
- Safety and compliance: Be aware of safety notes, such as return policies and end-of-life disposal requirements in transformer products. Follow applicable electrical codes and manufacturer installation guidance.
- Maintenance and service life: Evaluate winding materials, thermal performance, and manufacturer support when planning for long-term reliability and potential servicing needs.
- Physical footprint: Larger kVA units or 3-phase transformers may require dedicated space and proper ventilation in equipment rooms or electrical closets.
Each product listed here serves different use cases, from compact control circuits to industrial power conditioning. When selecting a transformer, align the device’s voltage range, current capacity, mounting style, and installation context with the specific load profile and safety standards of your facility. Always consult manufacturer datasheets and, if needed, a licensed electrician to ensure proper sizing, wiring, and compliance with local electrical codes.