vault backup: 2026-04-14 17:14:20

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.
+
 $$
 Z = \frac{ \Delta V }{ I \times M \times L }
 $$