Hello:

Just wanted to get the general opinions on the following that was being discussed:

The statement:

30 amps will develop 2 1/4 times more heat than 20 amps in a conductor
The data to backup the claim:

Most of us know that developed power is the product of the voltage and current, but voltage is equal to the current multiplied by the resistance, Hence:

P=VI V=IR

Substituting: P=(IR)I P=I(squared)R

The resistance for the conductor hasn't changed but the current has changed from 20A to 30A. 30 is 20(1.5):

P=(1.5)(squared)R 1.5 (squared) = 2.25 P=2.25R

To me this is a wee bit simplistic, it doesn't take into consideration size of conductor, ambient temperature, length of run etc...

Just wanted to get the general opinions on the following that was being discussed:

The statement:

30 amps will develop 2 1/4 times more heat than 20 amps in a conductor

Most of us know that developed power is the product of the voltage and current, but voltage is equal to the current multiplied by the resistance, Hence:

P=VI V=IR

Substituting: P=(IR)I P=I(squared)R

The resistance for the conductor hasn't changed but the current has changed from 20A to 30A. 30 is 20(1.5):

P=(1.5)(squared)R 1.5 (squared) = 2.25 P=2.25R

To me this is a wee bit simplistic, it doesn't take into consideration size of conductor, ambient temperature, length of run etc...