Does the National Electrical Code (NEC) require all lighting installations operating at 30 volts or less to be Listed systems? Can individual low-voltage lighting components, such as a power supply, fixtures, and conductors be assembled in the field without being part of a Listed system?
CODE CITATIONS Article 210—Branch Circuits Article 250—Grounding Article 424—Fixed Electric Space Heating Equipment Article 700—Emergency Systems Bonding gas piping Q: The November 2000 issue of Electrical Contractor magazine included a question about the required size of the bonding conductor to be
The hazardous locations covered by Chapter 5 of the National Electrical Code (NEC) are classified in accordance with the properties of flammable liquids, gases, vapors, combustible dust, or ignitable fibers or flyings that may be present in the area where electrical equipment may be installed.
February’s “Code Question of the Month” column addressed overcurrent device installation in clothes closets. The questions were: (1) May service equipment (overcurrent devices in a panelboard) be installed in a walk-in clothes closet?
Should motor control circuits be grounded? Here are some guidelines:
If a motor control circuit is tapped from the motor circuit and does not leave the controller enclosure (the push buttons are in the cover), then it need not be grounded. [90-7 ¶ 2, 300-1(b), 450-1 Exc.No.2]
The temperature rating associated with the ampacity of a conductor must be selected and coordinated so that the lowest temperature rating of any conductor, equipment termination, or electrical device is not exceeded.
Last month, we reviewed the basic requirements for grounding separately derived systems in accordance with Article 250 of the National Electrical Code (NEC). This month, we will explore a proposed 2002 Code change and how it might impact safety.
2002 NEC proposal
The column this month will cover questions about transformer installations that were the subject of concern to subscribers to NECA’s on-line “Code Question of the Day.” All answers are based on the current 1999 edition of the National Electrical Code (NEC); however, beginning with this month’s colum