As an Amazon Associate, SparkShift earns from qualifying purchases. SparkShift also participates in other affiliate programs designed to provide a means for us to earn fees by linking to Amazon.com, HomeDepot.com, and affiliated sites. View our affiliate disclosure policy
SparkShift is an independent tool for electricians and is not affiliated with, endorsed by, or an official product of the International Brotherhood of Electrical Workers (IBEW), the National Joint Apprenticeship and Training Committee (NJATC/electrical training ALLIANCE), or any specific JATC or local union unless explicitly stated.
National Electrical Code® and NEC® are registered trademarks of the National Fire Protection Association, Inc., Quincy, MA. SparkShift is an independent software provider and is not affiliated with, authorized, endorsed, or sponsored by the NFPA. All calculations are for reference only and must be verified by a licensed professional.