JavaScript is required to use the Windy City Wire site Loop Resistance Definition | Windy City Wire

Loop Resistance

Definition

Loop resistance is the total resistance of two conductors measured round-trip from one end, accounting for the complete out-and-back path that current follows in a circuit.

Detailed Explanation

Loop resistance measures the combined resistance of the two conductors that form a circuit, taken as a single round-trip value from one end of the cable. It reflects the resistance current encounters traveling out along one conductor and back along the other, giving a practical figure for the complete path. This single number captures what the circuit actually experiences rather than the resistance of one conductor alone.

In commercial and industrial systems, loop resistance is important for predicting voltage drop, signal loss, and power delivery over a cable run. Conductor size and length both influence the value, with longer runs and smaller conductors producing higher resistance. Engineers use loop resistance to confirm that a cable can supply adequate voltage and signal to equipment at the far end, which is especially important for powered devices on long runs.

Temperature also factors into the value, since conductor resistance rises with temperature, so a run evaluated for worst-case conditions accounts for the warmest environment the cable is expected to encounter in service.

At Windy City Wire, the focus on quality low-voltage cable connects to the conductor characteristics that determine loop resistance. Supplying cable with appropriate conductor sizing helps customers manage voltage drop and signal loss, so equipment at the end of a run receives the power and signal it needs.

Applications / Use Cases

  • Predicting voltage drop over a cable run
  • Evaluating signal loss in circuits
  • Confirming power delivery to remote equipment
  • Comparing conductor performance by length and size
  • Sizing conductors for powered devices on long runs

Related Terms

  • Resistance
  • Voltage Drop
  • Conductor
  • Loss Factor
  • Low Loss