In dual-voltage motor configurations, the high-to-low voltage ratio is what?

• A. 1 to 2
• B. 1 to 1
• C. 2 to 1
• D. 4 to 1

Answer: (C)

The high-to-low voltage ratio for dual-voltage motors is 2 to 1.

These motors let you run on two voltages by reconfiguring the windings. For the lower voltage (e.g., 230 V), the windings are wired in parallel so each winding sees 230 V and the current capability increases. For the higher voltage (e.g., 460 V), the windings are wired in series so the total across the windings is 460 V, with each winding dropping about 230 V. So the high voltage is roughly double the low voltage, giving a 2:1 ratio. The other options would not reflect this typical 230/460 V dual-voltage setup.