Guides
Procedures in the order the code applies them, with worked figures produced by the same engines as the calculators. Written for the licensed trade rather than as an introduction to electricity.
- How to Size a Wire to NEC RequirementsHow do I size a conductor for this circuit?7 steps
- Conductor Derating ExplainedWhy did derating increase my conductor size?5 steps
- How to Calculate Conduit FillHow do I calculate fill when the pull has mixed wire sizes?5 steps
- How to Check Voltage DropWhen does distance force a larger conductor?5 steps
- Residential Load Calculation 220.82How does the optional dwelling load calculation work?5 steps
- Adding Load to an Existing Panel 220.83Can an existing service handle a new EV charger or heat pump?5 steps
- EV Charger Circuit SizingHow do I size an EV charger circuit?5 steps
- Service Upgrade from 100 to 200 AmpsWhen does a house need a 200 A service?5 steps
- Aluminum Feeder SizingWhen is aluminum the right feeder conductor?5 steps
- Terminal Temperature Ratings 110.14(C)Why does the terminal rating cap the conductor result?5 steps
- Continuous Load and the 125 Percent RuleWhen does a load need the 125 percent multiplier?5 steps
- Subpanel Feeder SizingHow do I size a feeder to a subpanel?5 steps
- Permit Load Calculation SubmittalWhat should a permit load calculation show?5 steps
- Choosing Conduit TypeWhich conduit type should I choose before checking fill?5 steps
- Common Wire Sizing MistakesWhich wire-sizing shortcuts produce wrong answers?5 steps