1-Phase Buck/Boost Step-Up Transformer - 208V Primary - 240V Secondary
Quick take
This 1-phase buck/boost step-up transformer is made to convert 208V AC to 240V AC for electrical loads up to 23.4A on the secondary side (5.53 kVA). It uses a NEMA 3R painted steel enclosure for indoor or outdoor installation, with front-access terminations and knockout wiring options. The main buying caveat is that it adjusts voltage only, it does not convert phases and it does not create a neutral if one is not already present.
Pros and cons
Pros
- Single-phase 208V to 240V step-up for loads up to 23.4A (5.53 kVA).
- NEMA 3R painted steel enclosure supports indoor and outdoor mounting (wall or floor compatible).
- Low-heat, high-efficiency design with 130°C insulation (80°C temperature rise).
- Front access and multiple knockout locations (side and rear, plus bottom) for wiring flexibility.
Cons
- Voltage conversion only, no phase conversion and no neutral creation.
- Does not provide even legs for line-to-line where L1 and L2 must be balanced.
- Return restrictions for transformers may limit options if you realize it is the wrong electrical fit.
What buyers think
Buyer-review evidence is very limited, with only a small number of ratings and brief feedback. Available comments are positive and focus on the unit performing as expected. Because the review history is limited, it is best to evaluate fit using the electrical specifications, mounting/enclosure details, and the stated limitations before purchasing.
Key specs that matter for choosing
Voltage conversion and capacity
This transformer is designed for single-phase service. It takes 208V AC on the primary and provides 240V on the secondary, with up to 23.4A available on the 240V side. The listed kVA rating is 5.53 kVA, which is a practical ceiling for the size of the connected load you plan to power.
Frequency and operating envelope
It supports 50/60 Hz operation. The insulation system is rated at 130°C with an 80°C temperature rise, which matters for planning installation conditions and expected continuous operation.
Construction and enclosure
The unit uses a NEMA 3R painted steel enclosure for outdoor-capable installation. The transformer is built with non-aging, cold-rolled silicon steel laminations, copper winding material, and a silica sand and resin encapsulation approach. These details point to a design aimed at reliability, moisture protection, and stable performance in demanding environments.
Terminations, mounting, and wiring approach
Wiring access is intended to be straightforward, with front access copper tabs or lead wires for both primary and secondary connections. Knockout hubs are provided on the side and rear, plus additional bottom knockouts to facilitate line-in and line-out wiring. The system is suitable for wall or floor mounting, and integrated wall mounting brackets are included to speed installation.
Who this transformer is best for
- Facilities with single-phase 208V power that need to run equipment designed for 240V.
- Users who need a weather-tough enclosure and expect installation in indoor or outdoor locations (NEMA 3R).
- Buyers whose equipment already has the correct phase and neutral requirements, since this is not a phase converter and does not generate a neutral.
- Installers or maintenance teams looking for a compact, front-access wiring layout with knockouts for flexible conduit routing.
Who should avoid it
- If you need phase conversion (for example, converting single-phase to three-phase, or changing phase relationships), this unit is not designed for that.
- If your application requires a neutral output that does not already exist, this transformer will not create it.
- If your design depends on even line legs between L1 and L2, the stated limitation about uneven legs is important to review before purchase.
Pros and cons in real-world terms
When it fits, the value is in targeted voltage matching
If your site has 208V single-phase and your downstream equipment expects 240V, a buck/boost approach can be a practical way to bridge that mismatch. The listed 5.53 kVA and 23.4A secondary capacity give you a clear target to compare against your load.
When it does not fit, it is hard to “work around”
The most common reason a transformer like this becomes the wrong purchase is needing features it cannot provide. Voltage conversion alone means you must verify your application already aligns on phase, neutral requirements, and any balance needs between line legs.
Buying checklist before you click
- Confirm input and output voltage needs: 208V single-phase in, 240V for the load.
- Check your load against capacity: use the 5.53 kVA rating and up to 23.4A at 240V as your ceiling.
- Verify your phase and neutral requirements: this unit does not convert phases or create a neutral.
- Plan mounting and wiring: confirm wall or floor placement, and how your conduit will route through side, rear, and bottom knockouts.
- Review return restrictions: transformer returns are restricted for safety reasons, so double-check electrical fit up front.
Price and availability
The unit is listed as in stock at the time of viewing. Pricing can change, so if you want the most current cost and seller details, check the button below.
FAQ
Does this transformer convert 208V to 240V only?
Yes. It is a step-up transformer intended to change voltage from 208V AC (primary) to 240V AC (secondary). It does not perform phase conversion.
Is it suitable for outdoor installation?
It is enclosed in a NEMA 3R painted steel housing, which is intended for indoor or outdoor applications.
What is the maximum output current?
The secondary side provides up to 23.4A at 240V, with a total rating of 5.53 kVA.
Does it create a neutral if my circuit does not have one?
No. It does not generate a neutral for applications where a neutral is not already present.
Can it balance L1 and L2 legs evenly?
It is not intended to create even legs between L1 and L2, so if your application needs balanced legs, you should verify compatibility.
What should I check to make sure it is the right transformer?
Verify the input voltage and single-phase requirement, confirm your load does not exceed the listed kVA and 23.4A secondary capacity, and ensure your application does not require phase conversion or neutral creation.
Bottom line
This Larson Electronics 1-phase buck/boost step-up transformer is a solid option when you have 208V single-phase power and need to supply 240V to equipment up to its rated capacity. It is built for durable installation in indoor or outdoor environments (NEMA 3R enclosure) and offers practical wiring access for installers. The key to avoiding a bad fit is confirming your application needs only voltage adjustment, not phase conversion or neutral generation.
Specifications
| Product Title | 1-Phase Buck/Boost Step-Up Transformer - 208V Primary - 240V Secondary - 23.4, 40 or 70 Amps - 50/60Hz |
|---|---|
| Category | Electronics > Power Accessories > Isolation Transformers |
| Brand | Larson Electronics |
| Manufacturer | Larson Electronics LLC |
| Item Weight | 25 Pounds |
| Brand Name | Larson Electronics |
| Model | 148185 |
| Part Number | 148185 |
| Unit Count | 1.0 Count |
| Power Source | Corded Electric |
| Mounting Type | Wall Mount |
| Current Rating | 23.4 Amps |
| Maximum Frequency | 60 Hz |
| Minimum Frequency | 50 Hz |
| Specification Met | NEMA |
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