Selection Made Easy

April 18, 2023

Selection Made Easy

Buck-Boost Transformer

Selecting the right buck-boost transformer for your specific job can be a bit tricky. That’s why I love the HPS Tool Box created by Hammond Power Solutions. When you provide a couple of key buck-boost transformer data fields (Number of Phases, kVA or Amps, Line and Load Voltage), the HPS Tool Box selects the best buck-boost transformer for your application.

Let’s look at an example:

Application Problem: Which buck-boost transformer do I need for my pumping application?

For your project the utility supplies 208V single phase power, but your pump motor is rated for 230V with full-load amps of 17.8A. This application requires a buck-boost transformer, but what size and model number do you need?


  1. Open up the HPS Tool Box website and click Buck-Boost Selector.
  2. Enter the key information for your Buck-Boost transformer application. See screen shot below.
    • Click Single Phase
    • Enter Measured Supply Voltage
    • Select Desired Load Voltage (select a value equal or greater than your required load voltage
    • Enter your desired Load kVA
    • Click the “Proceed to Results Page” on the bottom right
Buck-Boost Selector Screen Shot
Buck-Boost Selector Screen Shot

After clicking the results button, you will be provided a Hammond Buck-Boost transformer model number, a wiring diagram and the number of buck-boost transformers required to achieve the desired output voltage. You can also save as a PDF if you need a hard copy for your project file.

Buck-Boost Transformer Model Number and Wiring Diagram
Buck-Boost Transformer Model Number and Wiring Diagram

I hope you find this tool as helpful as I do.

Buckles-Smith is an electrical distributor with multiple stocking locations throughout Northern California and the San Francisco Bay Area. Contact us today for any questions you may have and we’ll help you out.