ResistanceChange

Resistance Change with Temperature

Ampacity Correction
Temperature Correction
Continuous Load Correction
Conduit Fill Correction
Minimum Number of Circuits
Bus Bar Ampacity
Conductor Resistance
Resistance Change
Motor Disconnect Sizing
Full Load Current Interpolation
Motor Conductor Sizing
Motor Overcurrent Protection
Motor Overload Sizing
Lighting Loads
Fixed Appliance Loads
Range Loads
Range Loads Note 1
Range Loads Note 2
Dryer Water Heater Loads
Heat AC
Standard Residential Service
Optional Residential Service
Standard Multi Family Service
Optional Multi Family Service
Commercial Services
Optional School Services
 
 
NEC Calculations Home
Electrician Math Home
Electrician Education Home
 

The calculation for change in resistance based on temperature change is included here as a calculator topic. Working electricians do not need to make this calculation.

As a conductor gets hotter, the resistance goes up. There is a calculation to determine the resistance at various temperatures. This calculation only works for temperatures which are higher than 75 degrees C.

Formula: resistance at 75 degrees C times ( 1 + .00323 times (new temperature minus 75) ) equals read answer

Be sure to include parenthesis, including the double one, where they are in the formula.

Find practice problems HERE.

Find audio support HERE.

 
 

 

Click on any of these titles from Amazon.com which may be of interest to you.
Order them directly from Amazon.com with a debit or credit card.

 

Many electrician workbooks and practice exams are now available 
as digital downloads for immediate use. 
Click HERE to see what is available.

Products For Sale
2006-2011 David U. Larson
dularson@bellsouth.net
Companion Website to ElectricianEducation.com ,
2011NEC.com and
TechnicianEducation.com
Other websites by David U. Larson which may be of interest:
VisitEuropeOnline.com

OldPostcardsForSale.com
StampDealerLots.com 
HouseFlipGuide.com
SwedenRoots.com
GreenfieldVillageOnline.com
6901st.org