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Electrical reference charts
Code tables and rating charts that come up when you specify transformers, feeders and the gear around them. Free, sourced and free to cite.
Wire ampacity chart from NEC Table 310.16
NEC Table 310.16 ampacities for copper and aluminum at 60, 75 and 90°C from 14 AWG to 2000 kcmil, with the terminal rule, small conductor limits and derating factors.
NEMA enclosure ratings chart
What NEMA Types 1, 3R, 4, 4X, 12 and the rest protect against, side by side, with the IP codes three published charts give for each and why they disagree.
Motor full load amps chart
Three phase motor full load amps from 1/2 to 500 HP at 115, 200, 208, 230, 460, 575 and 2300 V from NEC Table 430.250, single phase from 430.248, with wire, breaker and kVA by HP.
What size wire for every amp rating, 15 to 4000 amps
Wire size by amps from 15 to 400 A in copper and aluminum, the dwelling service sizes under NEC 310.12, and parallel sets for 400 to 4000 A services, with a calculator.
Primary distribution voltages, 4.16 kV to 34.5 kV
Every standard US primary voltage from 2.4 kV to 69 kV with its phase to ground value, wye or delta, insulation class and BIL, and what 12470Y/7200 on a nameplate means.
Commercial electrical service sizes, amps, kVA and transformer
Standard commercial service sizes from 100 to 4000 amps at 208Y/120 and 480Y/277 volts, the kVA each one carries, the transformer that feeds it, and when ground fault protection applies.
Breaker size chart, every standard breaker rating and its wire size
Every standard breaker size in NEC 240.6(A) from 10 to 6000 amps, the matching copper and aluminum wire size at 60 and 75°C, the 125 percent continuous load rule and common appliance circuits.
Need current at a transformer rating instead? Use the kVA to amps calculator or see all tools.