Mathematics (26303) -

: Defined by the NEC (National Electrical Code). Class I involves flammable gases, Class II involves combustible dust, and Class III involves ignitable fibers.

The identification code does not typically refer to a mathematics course or guide. Instead, it is most commonly associated with NCCER Electrical Level 2, Module 26303: Practical Applications of Lighting . Mathematics (26303)

This module provides the fundamentals for electrical trainees regarding different lighting technologies and their physical installation. : Direct Lighting : 90% to 100% of light is directed downward. : Defined by the NEC (National Electrical Code)

If you are studying this module, it covers the technical and safety aspects of installing and maintaining lighting systems rather than pure mathematics. Below is a summary of the core topics found in this specific guide: Instead, it is most commonly associated with NCCER

: The unit for measuring illuminance (light falling on a surface). One lumen falling on one square foot equals one footcandle.