Electrical
What this tool does
DC or three-phase AC voltage drop compared with NEC branch and feeder guidance. This page says what the tool is for, in plain language. The working formula stays on the signed-in tool.
When to use it
Open Conductor voltage drop when this is the job: DC or three-phase AC voltage drop compared with NEC branch and feeder guidance. That is usually a loop, a conductor, a raceway, or a barrier you are about to accept or reject.
Step-by-step
- Open Conductor voltage drop from the tool list.
- Fill Circuit, Source voltage, Current, One-way length from the instrument, the drawing, or the job record. Use the unit shown beside each field.
- Fill the remaining fields the same way. Skip a field only when the screen marks it optional.
- Run Calculate when that control is on the page, then read every result row and any warning.
- Check the result against the site procedure and the manufacturer data before you change a range, a wire, a setpoint, or a weight.
- This help page is public. Opening the tool still requires a Pro session.
Inputs
- Circuit
- Direct current or three-phase alternating current, matching the source.
- Source voltage
- The voltage at the source end of the run.
- Current
- The load current used for the drop.
- One-way length
- The length of one conductor path. The tool applies the round trip when the circuit needs it.
- AWG
- The conductor size from the drawing or the cable jacket.
- Conductor
- Copper or aluminum, matching the metal in the cable.
Results
- Result
- The reported value for Conductor voltage drop. Use the unit printed on that row.
- Warnings
- A warning means an entry is incomplete or outside what this tool will stand behind. Recheck the inputs and the site procedure.
Common mistakes
- Using the wrong metal, the wrong insulation column, or a one-way length where the circuit is a round trip.
- Comparing barrier and device parameters that are not from the same certificate columns.
- Applying a fill or ampacity table to a raceway or a wire the table does not cover.
- Do not treat a result from Conductor voltage drop as a substitute for the site procedure or the manufacturer data.
Standards references
These are the standards and public references named on this tool. Clause numbers appear only when the catalog already cites them.
- NEC voltage-drop informational notes (branch-circuit and feeder guidance)
- Conductor resistance tables used with those notes
Offline and access
This engine can run offline after the server has cached it for the signed-in account.
A free session can read this help page. The tool card shows the name and the short summary. Opening the tool requires Pro.