Double-layer insulated torque wrench and screwdriver for electric vehicles
Variable speed fire pump with fire manager
HotSpot "EZ Exit" LED emergency system
EVO-P point-by-point pump synchronous lifting system
Thomas Domitrovich, PE, LEED AP, Eaton, Ken White, retired, Olin Chlor-Alaki and security coordinator Jim Dollard, IBEW Local 98, answered the following webcast viewer questions related to NEC 240.87 code requirements:
Question: To what extent is the foreman/supervisor responsible for following the arc fault safety, procedures for calculating the safety distance?
Question: How should PPE be selected according to NFPA 70E Annex H and Table 130.7(C)(16)? Why are these two tables different for the same energy level? After the analysis, should we not use the hazard/risk category?
Q: Can you discuss why NFPA 70E has different PPE selection methods, and why they are different for the same incident energy? Namely Annex H and Table 130.7(C)(15)(a)
Question: Have you developed a sufficient and practical automatic dimmer cover?
Question: Jim or Tom, please explain how NEC-2014's requirements for 1200A circuit breakers affect existing equipment. How about overcurrent protection such as fuse?
Question: When using the "reduced arc energy maintenance switch", the risk of starting the overcurrent device will definitely increase slightly. Before adjusting the switch, do you have to wear FR clothing suitable for the arc flash rating-then reduce your arc flash clothing to the next level?
Q: Is there a code that requires marking of arc flash hazards, or is it just based on NFPA 70E best practices?
Q: What type of clothing must be worn under the arc flash suit?
Question: [Is] NFPA 70E will solve the programmable trip circuit breaker with arc flash mitigation function in the future?
Question: Before turning on the switchgear, what safety devices should we use to protect ourselves? Are there any specific types of safety devices, such as the thickness of rubber/leather gloves, shoulder straps, glasses, etc.? Thank you.
Q: On-site work and OSHA's position?
Q: There seems to be a conflict between A/F and selective coordination (in '14)?
Q: Your discussion seems to solve maintenance issues more than uptime. Do injury statistics (maybe) only include accidents that may include end users?
Q: What is the fundamental difference between IEEE 1584 and NFPA70E requirements.
Q: Can you determine the specific language in NEC and NFPA70E that requires FM to conduct AF research?
Question: After you read the detailed rules, it seems that the PPE form in 70E is almost worthless. Basically, if arc fault studies are not carried out, whether they are applicable is still a guess. How do you use them?
Q: According to the latest NFPA 70E, mandatory changes are made to the arc flash label system. How do we standardize the calculation methods of various factories of different installation contractors? Which areas of the world currently have mandatory arc flash labeling systems?
Q: How to contact the presenter?
Q: What changes have been made to the strict requirements between 70E in 2009 and 70E in 2012?
Q: Do we need to set a hazard level for all equipment above 50 volts, or only for equipment between 50 volts and 240 volts and equipment with a transformer rating higher than 112.5 KVA?
Question: Is the maintenance switch a standard function of circuit breakers greater than 1000A, such as all major manufacturers?
Question: What is the arc flash protection for the installation and use of 480 VAC on the line side (and the question of using the NFPA-70E table)?
Question: 240.87 does not seem to actually "require" the use of circuit breakers. It also does not seem to "require" a solid-state release to be necessary; it says, "The highest rated current...where it is installed." What if a "fuse" is provided?
Q: What is OSHA's interpretation of live? Especially in the lockout/tagout confirmation operation, how realistic is it to reduce the hazardous area and still carry out selective coordination?
Question: Referring to NFPA 70E-2012, Article 130.5, I have encountered many people who think that it is necessary to conduct arc flash hazard analysis on circuits below 240v, powered by 125KVA and below, just because NFPA 70E does not declare it. is this correct?
Question: Tom, after the maintenance switch is in place, is it a good idea to provide two different arc flash hazard labels for two different time curves?
Q: Ken White, in the case study, is the circuit breaker in Cubicle 4 a feeder or a main line? How many power system outages? Voltage, grounding system?
Q: What role does OSHA play in these requirements?
Q: How do you deal with situations that cannot be lower than CAT4?
Q: Can you discuss the requirements of arc flash 208v and nfpa 70e?
Q: What is the most cost-effective and effective strategy to reduce arc flash?
Q: What is the role of consultants in meeting regulatory requirements?
Question: Why is there no time reduction in seconds in 240.87? How much should the cleaning time be reduced?
Q: Can you discuss the trade-off between arc flash mitigation and selective coordination?
Question: Clarification: Does 240.87 apply to non-adjustable circuit breakers?
Q: Please discuss the impact of reducing arc flash hazards and coordination of protective devices.
Q: Ken, are there any safety observers who did not participate in the work during the work? If not, why not?
Q: When the gfci socket is to replace the traditional socket in the kitchen, do I need to install an arc fault circuit breaker?
Q: Are there any ways to reduce arc flash of old switchgear? How does the size of the upstream transformer affect the arc flash calculation?
Question: Please recommend software for arc fault calculation.
Q: Can you retrospectively discuss the use of arc reduction strategies in existing facilities? And how to convince the owner/manager to conduct an arc flash study to implement an arc reduction strategy?
Q: First of all, can you explain/discuss the effect of obstacles (switch cabinet/MCC door, plexiglass cover, etc.) on the arc flash energy level outside the equipment where people may stand? In addition, can you discuss the difference between the hazards of arc flash to personnel?
Q: Can you discuss the arc-resistant structure and arc termination/interruption? In addition, can you discuss cost-effective arc mitigation strategies and compare arc flash mitigation with OCPD selective coordination?
Q: How can we best close the gap between new security methods that use cumbersome methods and old-school thinking? Is it just through education, education and more education?
Question: What are the advantages and disadvantages of arc-proof gears and arc-suppression gears?
Question: Does the instantaneous trip circuit breaker meet the requirements?
Q: Does the correctly set instantaneous trip (set to be lower than the expected arc current level) meet the requirements of the specification as an approved equivalent means or active mitigation system?
Q: When amperage is not necessarily a predictor of high incident energy, why use amperage to define the requirements for additional measures?
Q: When it is determined by calculation that the safe approach boundary is not even in the room where the equipment is located, what are our responsibilities besides attaching the danger label?
Q: Can you discuss the issue of arc flash reduction in coordination, especially for emergency and backup systems?
Q: When do you expect Pennsylvania to adopt the 2014 NEC?
Question: Can you discuss non-instantaneous circuit breakers below 1200A?
Q: Does the existing arc flash research need to be re-evaluated and certified? 2How will the new regulations affect old (1970s and before) factories? And how to get regulations and NEC 2014 Section 240.87 for free-is a corporate membership required?
Question: What is the definition of arc flash?
Q: If arc flash studies show that there is no harm, is it really necessary to comply with 240.87?
Q: What are the advantages of ARMS and ZSE?
Q: Which cities are adopting this approach, and when will the new regulations take effect?
Q: What is the number of arc flash events in the past 25 years, and is the number declining?
Q: What are the arc protection accessories for warehouse operations?
Question: All the covers on the equipment are exposed, only one operating handle is exposed. Does the operator need PPE to operate the circuit breaker/switch?
Q: For land-based facilities, is an arc flash PPE required to open the enclosure, or is it only necessary if certain measures are taken to generate an arc?
Question: What energy saving method did Mr. White use? That is, light detection, main maintenance switch, etc.
Question: During the incident, is there any QC or other approval while the work is in progress? Is "replacement of equipment used to perform work" discussed in the pre-work plan? Is the lesson to be learned almost to be signed during the QC work of the process safety personnel?
Q: Who is certain that the equipment may work on site?
Q: If you only turn off the 480V circuit breaker that supplies power to your lineup, why is the entire factory shut down? Did it lose coordination, so the main circuit breaker was also tripped?
Question: Is ARMS a pure maintenance tool, or is there a specific load profile or site configuration that can tolerate an always-on accident energy reduction design?
Q: Will the maintenance switch operate the circuit breaker faster than when the trip unit is momentarily set at its minimum setting? I found that if you keep the instantaneous setting below the arc current, you can't do better. This will be my equivalent. Unless the circuit breaker can run faster, you can't do better as long as the settings allow the influx of downstream equipment.
Q: If the maintenance switch is faster than setting the momentary to the minimum setting, does the modeling software (such as SKM and Easypower) publish this travel time in their software library? Is this a setting in the software?
Q: Can you use molded case circuit breakers for differential protection schemes without installing a bunch of additional CTs? The ZSI system is suitable for molded case circuit breakers without a lot of additional hardware.
Question: How does the arc flash reduction requirement for 1200AF circuit breakers and higher versions affect the maintenance of existing devices?
Q: Which manufacturers have maintenance switches?
Q: For maintenance settings, do you have to have a separate arc flash label?
Q: If you have a 1200 amp circuit breaker with a 400 amp rated plug, does this apply? That is, if the circuit breaker needs to physically replace the rated plug, does this need to meet 240.87?
Question: Tom, does the new clause 240.87 require the installation of arc suppression devices on the trunk and feeder lines in the same equipment (ie the 3000A main circuit breaker in the SWGR and the 1200A feeder circuit breaker)?
Q: If a short-term power failure occurs when the deceleration switch is activated, will it affect the trip sequence?
Question: Given that all four prescribed methods rely on the operation of arc fault currents, what evidence must be provided to prove their effectiveness?
Q: How will energy-saving maintenance switching affect selective coordination requirements?
Question: Reference 240.87: Has there ever been an event in which a circuit breaker with a rated current of less than 1200 amperes should be considered to reduce the clearing time?
Question: Tom, I just started working in a higher education institution, which has limited internal maintenance knowledge and no arc flash analysis. I am trying to persuade the need for identification, but I am always questioned. Is the ARC-Flash investigation a law?
Q: Is 240.87 Arc Energy Reduction just to reduce clearance time? Does it not need to calculate a specific reduction in incident energy, for example from 15 Cal/cm^2 to 3 cal/cm^2?
Q: How do these requirements affect the modified switch?
Q: Can you discuss the code that stipulates that currents of 1200 A and above should have arc flash mitigation technology as outlined in NEC 240.87? If the calculation on the device is CAT 0, what is the direction? Does this meet criterion five?
Q: If multiple 1200A devices are teamed with one MAIN, does MAIN only need technology? Or on all 1200 A devices?
Question: What is the difference between reducing the arc flash maintenance switch and lowering the short-time stroke setting during maintenance? I think this may not be the best practice, because it must be reset to ensure coordination, but does this meet the same intention of maintaining the switch?
Q: Does Eaton’s N-frame (1200A) plastic case electronic trip circuit breaker have an ARM switch?
Question: Tom: For N and R frame circuit breakers, is ARMS activated only by manual operation of the dial (in the arc flash area) or through digital input (outside the area)?
Question: Is it common for typical electronic trip circuit breakers over 1200 A to be equipped with standard arc fault reduction devices when they leave the factory?
Q: Can you explain more about zone interlocking? For example, how many levels does it need to interlock?
Question: Ken – OSHA (29 CFR 1910.333) emphasizes that no work should be performed on live electrical equipment higher than 50 V, unless: (1) the power failure of the equipment will cause greater safety hazards; or (2) due to equipment design or Circumstances where the power cannot be cut off due to the nature of the work performed. Does the job you almost missed meet this standard?
Question: In addition to methods 1, 2 or 3, what other recommended methods can reduce the impact of the main circuit breaker on the line side?
– Editor of Jessica DuBois-Maahs, Deputy Content Manager, CFE Media, jdmaahs (a) cfemedia.com
BMG Advanced Digital Readiness™ platform
Aluminum distribution box for control equipment and signal
Greenheck redesigns Energy Core ventilator series