Loop Resistances for N-Pair Power Delivery
In Fig. 13.1, we first calculate the loop resistances, assuming simply that 100 m of a single strand of CAT3/AWG26 is 20 , and 12.5 for CAT5e/AWG24. We see that as a coincidence, in the case of two-pair power delivery, the loop resistance is the same numerically. For one pair it is double that, and for four pair it is half of that. We use these numbers in the calculations that follows.