The National Fire Alarm Code does not require anyone to install a fire alarm system. That statement sometimes surprises contractors who have been told by a fire official to install a fire alarm system in accordance with NFPA 72.
Recently, an inspector and contractor called me concerning a 277/480-volt feeder circuit that was designed to comply with the 2008 National Electrical Code (NEC) and supplied a building from the service equipment located in a substation switchboard room.
Everyone in the electrical industry, including the electrical apprentice, the journeyman, the master electrician, electrical contractor, electrical engineer, designer, the electrical inspector, et al., seem to use the phrase “neutral conductor.” However, until the 2008 National Electrical Code (NEC)
Occasionally, a change occurs in the National Electrical Code (NEC), and the ramifications are not realized until after the Code is issued. One such change can be found in Section 210.4(B) in the 2008 NEC.
JaeI receive many questions on how to design and install the electrical system for a separately derived system, including the use of the grounded neutral conductor. Naturally, grounding and bonding the secondary side always is a major issue as well as how the neutral conductor is used.
There were 3,688 proposals for changes to the National Electrical Code (NEC) and 2,349 comments processed by the National Fire Protection Association (NFPA) staff at its headquarters in Quincy, Mass. The following is part three in a series of significant changes for the 2008 NEC.
Article 110 Requirements for Electrical Installations; Article 210 Branch Circuits; Article 220 Branch Circuit, Feeder, and Service Calculations; Article 310 Conductors for General Wiring; Article 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS; Article 358 Electrical Metallic Tubing: Type EM
After addressing the lighting and exterior area of the premises last month, this month’s article concentrates primarily on internal security of the building, using Article 708 covering critical operations power systems (COPS) in the 2008 National Electrical Code (NEC).
The 2008 National Electrical Code (NEC) has been revised by declaring the appropriate procedure for calculating the load to size the neutral conductor. There has always been a controversy between designers on the application of the NEC concerning this calculation.