The fundamental purpose of overcurrent protection is to protect conductors and equipment against the effects of excessive temperature on conductors and conductor insulation from overcurrent. Some of the issues we might not be fully familiar with are these: What devices are suitable for branch and feeder overcurrent protection? Matching device rating to system voltage Application [...]
(No Ratings Yet)One of the most fundamental elements of an electrical installation is the connecting of the wiring method to an overcurrent device. Seems simple right? All most people seem to do (including inspectors) is to look at Table 310.16 and match up the numbers to a fuse or breaker. Unfortunately the actual selection process can be [...]
(No Ratings Yet)The 2002 National Electrical Code (NEC) requires that the branch circuits supplying outlets of dwelling unit bedrooms, as well as mobile homes and manufactured home bedrooms, be protected by arc-fault circuit interrupters (AFCIs). Rules 210.12 and 550.25 are clear in this requirement. However there is considerable confusion as to which type of AFCI meets the [...]
(No Ratings Yet)
Overcurrent devices protect the circuit conductors and conductor insulation from overheating. They also limit the damage associated with overheating and faults in downstream equipment. Fuses performed this function during the first days of electrical distribution, but circuit breakers of ever increasing sophistication have been available since the early 1900s. This paper focuses on circuit breakers [...]
(No Ratings Yet)
Grounding separately derived systems is required where the system meets the characteristics of 250.20. This section gives the conditions under which electrical systems are required to be grounded. A system that is grounded has one conductor of the system intentionally grounded. Whether the system is required to be grounded or is grounded by choice, it [...]
(No Ratings Yet)
Applying the rules of the 2002 NEC for tap conductors is a topic that has generated many interesting code discussions on jobsites as well as at inspector meetings. The discussion and application of the tap rules in the NEC must begin with the conductor in question.
(4 votes, average: 4.25 out of 5)Question: GTO cable in raceway Does UL List a GTO cable that does not need to be installed in a raceway?
(No Ratings Yet)
The 2002 National Electrical Code (NEC) requires that the branch circuits supplying outlets of dwelling unit bedrooms, as well as mobile homes and manufactured home bedrooms, be protected by arc-fault circuit interrupters (AFCIs). Rules 210.12 and 550.25 are clear in this requirement. However there is considerable confusion as to which type of AFCI meets the [...]
(No Ratings Yet)The Canadian Electrical Code, Rule 14-612 Transfer Equipment for Standby Power Systems prohibits the simultaneous connection of two or more power supplies to electrical equipment and facilities. There is an obvious exception. Rule 14-612 does not apply to parallel generation systems covered by Section 84 — Interconnection of Electrical Power Production Sources. Section 84 does [...]
(No Ratings Yet)
The first thing one notices about Article 305, Temporary Wiring, in the 2002 National Electrical Code is that it is no longer there! By direction of the Technical Correlating Committee, Article 305 has been relocated to Chapter 5 and re-identified as Article 527. Why move it and just add to all the confusion of finding [...]
(No Ratings Yet)
IAEI, as the keystone of the electrical industry, is a membership driven, non-profit association promoting electrical safety throughout the industry by providing premier education, certification of inspectors, advocacy, partnerships and expert leadership in Electrical Codes and Standards development.
Bad Behavior has blocked 2540 access attempts in the last 7 days.