Note 1. Vmax, Imax, and VAmax are determined with the current limiting impedance in the circuit (not bypassed) as follows:
Vmax: Maximum output voltage regardless of load with rated input applied.
Imax: Maximum output current under any noncapacitive load, including short circuit, and with overcurrent protection bypassed if used. Where a transformer limits the output current, Imax limits apply after one minute of operation. Where a current-limiting impedance, listed for the purpose, or as part of a listed product, is used in combination with a nonpower-limited transformer or a stored energy source, e.g., storage battery, to limit the output current, Imax limits apply after five seconds.
VAmax: Maximum volt-ampere output after one minute of operation regardless of load and overcurrent protection bypassed if used.
Note 2. For nonsinusoidal ac, Vmax shall be not greater than 42.4 volts peak. Where wet contact (immersion not included) is likely to occur, Class 3 wiring methods shall be used or Vmax shall be not greater than 15 volts for sinusoidal ac and 21.2 volts peak for nonsinusoidal ac.
Note 3. If the power source is a transformer, (VA)max is 350 or less when Vmax is 15 or less.
Note 4. For dc interrupted at a rate of 10 to 200 Hz, Vmax shall not be greater than 24.8 volts peak. Where wet contact (immersion not included) is likely to occur, Class 3 wiring methods shall be used or Vmax shall not be greater than 30 volts for continuous dc; 12.4 volts peak for dc that is interrupted at a rate of 10 to 200 Hz.
Article 90 Introduction
Wiring and Protection
Wiring Methods and Materials
Equipment for General Use
Annex C. Conduit and Tubing Fill Tables for Conductors and Fixture Wires of the Same Size
Annex D. Examples
Annex E. Types of Construction