The NEC (National Electrical Code) issued by the NFPA (National Fire Protection Association) is considered by almost all 50 states to regulate electrical installations in new buildings and innovative projects.
NFPA has released the latest issue of NEC 2005, which is enforceable in all states and municipalities that use NEC. Several provisions of the new specification affect lighting, including lighting control panels, metal halide lamps, and the removal of fluorescent lamps before service.
2005 NEC came into effect on January 1, 2005, but different states (or different municipalities) will take different time. Based on the 2002 NEC adoption ratio, several states may adopt the new specification immediately, and about half of the states will gradually adopt it in 2005. NEMA (International Electrical Manufacturers Association) said that in the new edition, several states including Texas, Southern California and New Hampshire have begun to adopt the 2005 NEC, but the implementation time of the relevant regulations is different.
Insured lamps in metal halide lamps
Metal halide (MH) lamps may have "non-passive failure" at the end of their useful life, causing the hot quartz components to fall out of the fixture. 2005 NEC in the 410.73 (F) (5) "metal halide lamp sealing device" for non-passive failure as follows: "Use a metal halide lamp instead of a thick glass PAR (parabolic reflector) light source (lamp), It must be equipped with a seal around the luminaire or a combination of materials that only allow the use of O-type luminaires." This means either a sealed luminaire (any sealed luminaire, including E and S), or an open optical luminaire Will be included in the scope of using only O-type lamps. Open luminaires featuring sockets can only use O-type luminaires.
O-type luminaires are insured luminaires, typically 175-1500W, with additional sealing around the curved tube. It features a special base (EX39) so it can only be operated on compatible special sockets.
The exception is MH luminaires that use thick glass PAR lamps. To a certain extent, the lighting industry has applied this rule to indoor open MH luminaires that operate below 350 watts. NEC now promotes it to all MH fixtures. In the future, UL may also refer to this requirement, and if UL is used as a standard requirement for luminaire manufacturers, then this regulation will truly become national, because there are still many states that do not immediately adopt 2005 NEC. .
This requirement is not expected to make a big difference to the specific operation. The authors need to ensure that the sealed luminaires are properly sized and that the open luminaires have a combination of materials that only operate O-type insured luminaires. In addition, they also need to ensure that the O-type insured luminaires have been specified. Overall, this requirement is expected to simplify existing MH system options.
Mixed use of sports and metal halide lamps and mercury vapor lamps in multi-purpose venues where the external bulbs of the luminaire may be broken during normal use in the venue. When the bulb is broken, the glass will slip off the fixture and fall into the place of use. In addition, the curved tube may continue to operate, which may cause the user to overexpose the UV radiation, which may cause sunburn or eye burns.
2005 NEC in Chapter 410.4(E) describes this situation as follows: “Lighting products that use mercury vapor lamps or metal halide lamps and may cause physical damage, are installed in indoor sports, mixed use or multi-purpose sports and In the auditorium area, use a light fixture with glass or plastic lens protection. These lighting products are permitted to use additional protective accessories."
NEC requires the use of glass or plastic lenses to completely seal these luminaires to prevent injury. Luminaires also need to be able to be fitted with an external barrier or cage, but this does not replace the necessary seals.
Detachment when the ballast is reinstalled Industry data shows that one of the primary causes of electrician's casualties is electric shock when operating on a 277 volt lighting system. Some believe that some of them are due to the fact that the circuit that prevents the luminaires from being removed from the service area is still under load, the electricians are often forced to export the ballasts, which leads them to ignore the correct warnings, instructions and training content.
NEC made some changes in this section of the "Disassembly Method" section of Section 410.73(G) to explain how to remove fluorescent fixtures to prevent possible electric shock hazards before electrical work is carried out. The content reads as follows: “In indoor installation locations rather than residences and related ancillary configurations, fluorescent lighting products that utilize dual-terminal luminaires and contain ballast(s) can be used for illumination or for reinstallation of ballasts The product must have a detachment method that removes all conductors of the ballast at the same time, if any, ground (neutral) conductors must also be included. This detachment method must be easy for the professional. Understand. "There are many exceptions to this rule. For example, the installation process or installation conditions make the regulations require appropriate changes, or the actual application process is not suitable for this regulation, such as hazardous area lamps and fluorescent escape signals.
However, this requirement will not take effect until January 1, 2008, and there will be enough time for the manufacturer to comply. Fundamentally, it is more like the 2008 NEC specification.
The lighting control panel is used to control the industrial control panels of systems such as lighting, transmission and air conditioning, and in most cases is field modulated. The individual devices used in the system can be listed, but the final finished panel is not. This is a cumbersome problem for both installers and detectors, as the use of panels continues to grow, with consequent growing panel misuse. Especially in the case of current overload, the power supply may exceed the SCCR (rated blown) value of a single component in the system.
In this regard, the first thing to do is to determine what constitutes an "industrial control panel" because the term is not yet common in commercial applications.
NEC 409.2 states: "Industrial control panel definition. Engine controllers, overload relays, fuse switches, circuit breakers and related control devices such as push-button control stations, selector switches, timers, switches, regulating relays and wiring A collection of systematic, standardized arrangements of two or more accessories, such as junction boxes, associated lights, or other similar accessories. Industrial control panels do not include controlled equipment."
"The focus of this definition is that it clearly indicates that the panel contains two or more devices," said Scott Jordan, marketing manager for Square D/Schneider Electronics. “In this way, a sealed enclosure containing multiple switching relays, either a relay and a timer, or a relay and a junction box, will be classified as an industrial control panel under this definition.†Similarly, he added, “Whether the manufacturer is supplying the entire assembly or all the lighting control panels that the customer has set up at the installation site, they actually need to comply with the NEC 409 regulations.â€
2005 NEC explains the industrial control panel in the new chapter 409 to promote safe installation and inspection of the panel. Prior to this, industrial control panels were installed based on the general requirements of other NEC chapters and certain state regulations. The new Chapter 409 covers all aspects of conventional industrial control panels that operate at 600 volts or less. Chapter 409 affects the design and installation of the control panel, ensuring that the entire panel and related accessories meet the SCCR values ​​specified in the application, and that the panels are marked with the appropriate SCCR value.
NEC 409.110 states: “Industrial control panels shall be marked with the following information that is readily visible after installation: (3) Short-circuit limits for industrial control panels based on one of the following: (a) SCCR list or label collection; b) SCCR established using accepted methods; FPN: UL 508A-2001 Annex SB is one of the accepted examples. The SCCR provisions in UL 508A are also a new regulation that will become a national standard in April 2006.
NEC also requires: “The SCCR value of the accessory or equipment shall be equal to or greater than the existing short-circuit current value at the installation location of the unit in the system.â€
NEC's regulations apply to OEMs, machine builders, and panel contractors, but it also affects other downstream professionals. For example, if an existing panel needs to be redeployed, the state will require compliance with the 2005 NEC and related regulations. If the panel is re-deployed following the 2005 NEC installation, the SCCR value of the panel must also be appropriate for the new deployment location. The inspector looks at the correct label on the newly installed or redeployed installed panel.
Source of information: Reprinted
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