Issue #18 - Available Short Circuit Fault Current Labeling
Dear Lady or Gentelman,
Arc Flash Newsletter is a quick update on arc flash issues and ARCAD solutions addressing these issues. This newsletter is free and will bring you up to date on the issues that surround arc flash and short circuit analysis. Visit us at www.arcadvisor.com for complete product offerings including free online arc flash, short circuit calculators, and PC-based software solutions for short-circuit, arc flash hazard analysis and labeling.
FAULT CURRENT CALCULATIONS AND LABELING
For the person whose tasks is the specification, coordination or maintenance of an electrical system, the available short circuit fault current is a major consideration in the selection of circuit protective devices. Knowing the available fault current and applying available fault current labels on new equipment is also now mandated by National Electrical Code (NEC). The NEC 110.24(A) states:
"Field Marking. Service equipment in other than dwelling units shall be legibly marked in the field with the maximum available fault current. The field marking(s) shall include the date the fault current calculation was performed and be of sufficient durability to withstand the environment involved."
Once the fault current has been calculated, labels made giving the available short circuit fault current, should be applied to the equipment. That information, and the date it was determined, must be put on a label that is field applied to the equipment. The purpose of this requirement is to allow the short circuit current rating (SCCR) of the equipment to be easily compared with the maximum available fault current.
We also believe it is critical to include system X/R rating at point of fault along with the available short circuit fault current data. This believe is based on the fact that all low-voltage protective devices are tested at predetermined X/R ratios. If the calculated X/R ratio at any given point in the electrical distribution system exceeds the tested X/R ratio of the overcurrent protective device, then you must de-rate the effective rating of the gear. This can be a very critical issue if your fault current calculation doesn't include the X/R ratio. A fault condition with a high reactive component can potentially require a de-rating of the gear to below the symmetric fault current value calculated at the gear. The SCA V1.0 software factors in both resistance and reactance components for every part composing the power system and provides an extremely accurate analysis of the maximum available short circuit fault current and X/R rating any part can be subject to.
* added arc duration cut-off for the range from 2 to 10 sec.
* included arc flash label template in more international languages
* added 300+ more fuses and breakers
* added protection device family to fuse and breaker displays
An accessible, easy to
use tool and a comprehensive companion to Arcad's PC software. The
features are simple to navigate without compromising on the range of
options. I particularly appreciate the depth of customization, down to
the language selection. I am yet to come across any glitches or bugs -
considerable accomplishment for a new app. Overall, very satisfied
and would highly recommend the software and app both.
by Jane Warren - Version 1.0.1 - Nov 22, 2013
I don't have any words! AWESOME!!! Easy to use and well done. Useful and accurate. Exactly what I wanted. Thnx.
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