What is the difference in wattage for a steamer rated for 208/240V when used at 208 volts?

What is the difference in wattage for a steamer rated for 208/240V when used at 208 volts?

• A. Wattage increases by 25%
• B. Wattage decreases by about 25%
• C. Wattage remains the same
• D. Wattage becomes unpredictable

Answer: (B)

When a steamer rated for 208/240V is used at 208 volts, the wattage it draws will decrease. This is due to the relationship between voltage, wattage, and resistance, as described by Ohm’s law (P = V^2/R). When the voltage decreases but the resistance remains constant, the power (wattage) also decreases. At 240V, the equipment is designed to operate at a higher power level. When it is operated at the lower voltage of 208V, the power output drops because power is proportional to the square of the voltage. Specifically, using a voltage that is about 13% lower than the rated maximum results in a decrease in wattage of approximately 25%. Therefore, when the steamer is used at 208 volts instead of its designed 240 volts, it effectively operates at a reduced wattage, which aligns with the answer provided.

When a steamer rated for 208/240V is used at 208 volts, the wattage it draws will decrease. This is due to the relationship between voltage, wattage, and resistance, as described by Ohm’s law (P = V^2/R). When the voltage decreases but the resistance remains constant, the power (wattage) also decreases.

At 240V, the equipment is designed to operate at a higher power level. When it is operated at the lower voltage of 208V, the power output drops because power is proportional to the square of the voltage. Specifically, using a voltage that is about 13% lower than the rated maximum results in a decrease in wattage of approximately 25%. Therefore, when the steamer is used at 208 volts instead of its designed 240 volts, it effectively operates at a reduced wattage, which aligns with the answer provided.