Houston Wire & Cable Company recommends that wire and cable ampacities be determined using the latest NEC tables and text. In particular, attention should be given to Articles 310, 392, 400-5 (flexible cords), and 501-4 Class I, II and III, Divisions 1 and 2 hazardous locations. Remember to use the "Ampacity Correction Factors" when the Ambient Temperature is different than those indicated in the Tables. Also, derating is required when using more than three conductors in a Raceway or Cable. Appendix B also contains helpful tables for Ampacity.