FieldengElectrical & Power
DC Circuit Voltage Drop
Two-wire DC voltage drop from one-way length and conductor resistance per unit length.
Electrical & PowerInstrumentation & Controls
Two-wire DC voltage drop from one-way length and conductor resistance per unit length.
App id: ELEC-20. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
Rtot = 2 × r × L, Vdrop = I × RtotInputs
| Name | Unit |
|---|---|
| Supply voltage (camera) | V |
| Load current (camera) | A |
| One-way length (optional) | ft |
| Resistance per unit length (optional) | ohm/ft |
| Total circuit resistance (optional) | ohm |
Outputs
| Name | Unit |
|---|---|
| Voltage drop (hero result) | V |
| Voltage at load | V |
| Voltage-drop percentage | % |
| One-way conductor resistance | ohm |
| Total circuit resistance | ohm |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
Screening bands in the app: < 3% · 3–5% · > 5%.
| When | Observation | Severity |
|---|---|---|
Voltage-drop percentage < 3% | Low voltage drop | info |
Voltage-drop percentage ≤ 5% | Moderate voltage drop | caution |
Voltage-drop percentage > 5% | High voltage drop | warning |
Assumptions
- Two-wire positive/return path with the same conductor resistance in both directions.
- Length is one-way. Total circuit resistance, if entered, replaces 2 × r × L.
- Direct current. Does not include temperature unless the entered resistance already does.
Provenance
- Two-wire DC feeder drop. Bands are engineering guidance, not code limits.