Page 41: of Maritime Reporter Magazine (April 2022)

TECH FEATURE UNDERSTANDING ARC FLASH contrast, the numbers become an active sections called out by 46 CFR (Code of and ongoing part of safety procedures Federal Regulations) for many decades. by being labeled on the electrical equip- So, this set of standards may have the ment. These labels warn the front-line strongest connection to those who de- worker of the danger. velop United States Coast Guard regula-

In concert with arc ? ash training and tions, and those who must abide by them.

a broader electrical safety program, workers are educated about what level MARINE OPERATOR EFFORTS of personal protective equipment is re- While not yet broadly required by quired for the various levels of arc ? ash regulation, several marine operators danger, speci? cally the incident energy have initiated arc ? ash investigation and levels listed in cal/cm2. mitigation efforts.

In 2013, the Canadian Coast Guard

REGULATORY REQUIREMENTS published a tender notice for arc ? ash

Even shore-side, there aren’t any clear- studies [7]. They implemented arc ? ash cut regulatory requirements for arc ? ash safety procedures on two vessels and studies or arc ? ash safety practices. But have been working to expand to addi- tragic high-pro? le accidents and the en- tional vessels.

suing ? nes and lawsuits have made them In 2014, the U.S. Army Corps of En- common practice onshore. As a result, Na- gineers began requiring vessels to meet tional Fire Protection Association (NFPA) arc ? ash standards (ER 385-1-100) [8].

Standard 70E has become the consensus This has been implemented on numer- standard for workplace electrical safety. ous vessels.

Organizations are guided by the policies EBDG completed arc ? ash studies for and procedures in this standard. all six of TxDOT’s Galveston ferries in

Marine standards have historically not 2016 [9]. Shore-side studies had already addressed arc ? ashes but are also begin- been performed for the terminals and ning to add arc ? ash requirements. DNV shore-side maintenance buildings [10].

now requires arc resistant switchgear for

ARC FLASH AND MARINE DESIGN medium voltage systems and generator sections of low voltage IMO compliant Space comes at a premium on a ship. systems (Rules For Classi? cation – Ships, For control and monitoring purposes, 2019, 4-8-2/9.2.2, 4-8-4/1.1.5, and 4-8- switchboards are often placed inside 4/2.2.1). In 2014, ABS added the require- the engine control room. But even for ments for both arc resistant switchgear low voltage switchboards, arc ? ash and arc ? ash hazard analyses for systems calculations are revealing that the inci- greater than 1000V [Currently MVR dent energy levels are much higher than 2020 4-8-1/5.1.7(b) and 4-8-5/3.7.4(e)]. thought. An accident in such a location usually that an arc initiating elsewhere

Lloyd’s Register added an entire sec- could not only lead to signi? cant injury will propagate to the input terminals tion dedicated to arc ? ash safety (Rules but make continued operation from the of a generator circuit breaker. In fact, and Regulations for the Classi? cation location very challenging. that worst-case may assume that it of Ships, 2019, Part 6, Chapter 2, Sec- Concerns regarding such an arc ? ash propagates to the maximum number of tion 8). This requires arc ? ash studies to are especially sensitive with regards to generators that might be online. The be performed even for low voltages. BV the main generator breakers. Should an possibility of this scenario may lead to requires arc resistant switchgear for me- arc ? ash develop on the input bus bar the construction of low voltage switch- dium voltage applications (C-2-13/6.2.5). to a generator circuit breaker, the circuit boards with generator entrance cubicles

In 2014, a variety of marine arc ? ash breaker cannot interrupt that ? ow. Dur- built to medium voltage switchgear safety requirements were created by ing an arc, the conductive ionized air standards. Medium voltage standards the Institute of Electrical and Electron- called plasma ? ows through the inside physically segregate the entrance cu- ics Engineers (IEEE): IEEE Std 45.5, of the switchboard. If an arc starts in one bicles and make such propagation from

Recommended Practice for Electrical location, it can be assumed that it will another location extremely unlikely.

Installations on Shipboard -- Safety Con- propagate to other locations. Another option is to push major pow- siderations. IEEE 45 has had numerous Thus, the worst-case assumption is er equipment outside of a manned space www.marinelink.com 41

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