diff --git a/alternating-current.md b/alternating-current.md index ba1a8ef..9a7738e 100644 --- a/alternating-current.md +++ b/alternating-current.md @@ -23,6 +23,12 @@ dg-publish: true * Ungrounded conductor - "Hot" * Grounded conductor - "Neutral" +## Impedance + +[resistance](https://en.wikipedia.org/wiki/Electrical_resistance) +[reactance](https://en.wikipedia.org/wiki/Electrical_reactance) +[impedance](https://en.wikipedia.org/wiki/Electrical_impedance) + ## 3-Phase Power The conductors between a voltage source and a load are called lines, diff --git a/timestamped/2026-04-14_15-50-06.md b/timestamped/2026-04-14_15-50-06.md new file mode 100644 index 0000000..7b6f125 --- /dev/null +++ b/timestamped/2026-04-14_15-50-06.md @@ -0,0 +1,44 @@ +--- +id: 2026-04-14T15:50:06-04:00 +aliases: [] +title: 2026-04-14 15:50:06 +tags: + - authorship/original + - destiny/permanent + - status/draft + - type/periodic/timestamped +dg-publish: true +date-created: 2026-04-14T15:50:06-04:00 +daily: "[[2026-04-14]]" +weekly: "[[2026-W16]]" +monthly: "[[2026-04]]" +quarterly: "[[2026-Q2]]" +yearly: "[[2026]]" +--- +# 2026-04-14 15:50:06 + +## Conductance + +**Conductance** is the reciprocal of [resistance](https://en.wikipedia.org/wiki/Electrical_resistance). + +The SI unit of conductance ($G$) +is the [siemens](https://en.wikipedia.org/wiki/Siemens_(unit)) (S). +"Mho" (ohm backwards) is an unofficial name and should be avoided. + +Like the ohm is also the unit of [reactance](https://en.wikipedia.org/wiki/Electrical_reactance) ($X$) +and [impedance](https://en.wikipedia.org/wiki/Electrical_impedance) ($Z$), +the siemens is also the unit of [susceptance](https://en.wikipedia.org/wiki/Electrical_susceptance) ($B$) +and [admittance](https://en.wikipedia.org/wiki/Admittance) ($Y$), +their respective reciprocals. + +*** + +For my purposes, +conductance is generally a far more practical quantity than resistance, +owing to that it increases with wire area and cost like ampacity. + +> [!info] Ohm's Law In Terms of Conductance +> +> $$ +> V = \frac{I}{G}, \quad G = \frac{I}{V}, \quad I = G \times V +> $$ diff --git a/voltage-drop.md b/voltage-drop.md index 050b0d8..9bd3ae2 100644 --- a/voltage-drop.md +++ b/voltage-drop.md @@ -103,13 +103,25 @@ where *** -It is often more useful to know the maximum length +When exact length is unknown, +it is often most useful to calculate the maximum length a certain wiring configuration is suitable for. $$ L = \frac{ \Delta V }{ I \times M } \times \frac{1}{Z} $$ +where +* $M$ is the "phase multiplier" (2 for single phase, $\sqrt{3}$ for 3-phase) +* $Z$ is the linear resistance of the wiring configuration + +*** + +When exact length is known, +it is often most useful to calculate the linear resistance +that will result in a specified voltage drop, +the maximum linear resistance for a specific feeder. + $$ Z = \frac{ \Delta V }{ I \times M \times L } $$