Re: [Distillers] Hey, Mike..........electrical element question
- brain_solenoid wrote:
Subject: [Distillers] Hey, Mike..........electrical element question
when you apply 110v to a 220v/240v water heater element, it cuts the power into a quarter of the rated wattage of the element.
I understand V=IR, and Watts = Volts x Amps ... but I don't understand how the power is quartered.
Can you explain why the power is quartered?
===============================================Hokay. Let's take a 1500W 240V rated element as an example.V = IR so I = V/RSubstitute for I in W = VI and we get W = V2/Rso R = V2 / WResistance of the 1500W element is therefore 240 x 240 / 1500 = 38.4 ohmsNow halve the voltage to 120V.W = 120 x 120 / 38.4 = 375 watts, which is a quarter of 1500WIn general, the relationship W = V2/R shows that the wattage varies with the square of the voltage, the resistance remaining constant (leaving aside considerations of resistance varying with temperature, which it does ... keep it simple!)Gottit?Mike N