Cable Reactance Issues
Cable Reactance Issues
(OP)
How is it that the reactance of a cable per unit it higher than it's resistance per unit? Under what conditions is this possible?
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RE: Cable Reactance Issues
For a 3-phase circuit with conductors in an equilateral triangle for example,
L=2x10-7ln[D/(re-1/4)] H/m
where D is the separation in meters and r is the radius of the condcutors
Stevenson, "Elements of Power System Analysis" is the canonical text on the subject.
RE: Cable Reactance Issues
in NFPA 70 National Electrical Code.
The resistance tends to be higher than reactance up to about 250kcmil. Past that, the reactance is higher than resistance.
RE: Cable Reactance Issues
Typically for 600V circuits in all but the smallest conductors, it may be worth noting that circuit reactances are greater with ferrous raceways compared to nonferrous and nonmetallic raceways. [NEC Ch 9 table 9]
RE: Cable Reactance Issues