Arc Flash 101. presented by Arc Flash Blaster LLC

Transcription

1 Arc Flash 101 presented by Arc Flash Blaster LLC

2 ARC FLASH?

3 ARC FLASH INCIDENT

4 STANDARDS AND REGULATIONS

5 Arc flash accidents... 35,000 F Molten Metal Pressure Waves Sound Waves Copper Vapour: (Solid to vapor expands by 67,000 times) Serious injuries can result. Intense Light Shrapnel Hot Air-Rapid Expansion

6 HAZARD? EVERY DAY... a USA worker is killed, 13 suffer lost time injuries due to electric shock or burns EVERY DAY... 1 in 20 on-the-job fatalities are due to electric injuries, 75% by electrical arcs

7 ONLY 240V

8 LESSONS LEARNED

9 GOVERNMENT FACILITY

10 LOW VOLTAGE PANEL

11 BACK OF SHIRT

12 POLYESTER SHIRT BUT GOOD GLOVES

13 SHERMCO INCIDENT ON FEB WORKERS RACKED IN A BREAKER 2 WORKERS OBSERVING DURING RACKING FELT RESISTANCE THINKING STIFFNESS IN RACKING SCREW HE BACKED BREAKER OUT

14 SHERMCO INCIDENT ACTUALLY IT WAS BROKEN CABLE TIES WITH LOOSE WIRING NO PRE-INSPECTION MADE CONTINUED RACKING IT PULLED WIRING DOWN ONTO 4160V BUS

15 What do the standards say? Wiring not run neatly

16 Relays damaged by heat

17 What do the standards say?

18 What do the standards say?

19 What do the standards Other cubicles were damaged by fault current flowing in the control wiring say?

20 What do the standards say?

21 INSTALLATION AFTER REPAIR Note wiring is held out of harm s way

22 RESULTS ESTIMATED INCIDENT ENERGY 33CAL/CM2 MAIN BREAKER CLEARED ON OVERCURRENT, ,000 AMPS LOWER DOOR SHIELDED WORKER, DOOR HANDLE HIT WORKER IN SIDE OF HEAD AND HE FRACTURED SKULL (NO HARD HAT)

23 THE SOLUTION?

24 ARC FLASH PROGRAM & ARC FLASH LABELS! WARNING Arc Flash and Shock Hazard Appropriate PPE Required Flash Protection Boundary ( feet or inches ) cal/cm 2 Flash Hazard at ( feet or (N/A = Not Calculated) inches) 18Q -2, Table 1 applies for Arc Flash PPE Determination Short Circuit Current Available (Amps) Reduction by one H azard Category in Table 1 Allowed Nominal Phase to Ground Voltage (18Q -2, Table 2) Date: Calculation # Bldg. Equip. Name / CLI #

25 Brady Solutions

26 PERSONAL PROTECTIVE EQUIPMENT (PPE)

27 PPE (will be changing) PPE Category Clothing Requirements Calorie Rating 0 Long sleeve shirt & pants (nonmelting), safety glasses, EARPLUGS 1.2 cal/cm FR shirt & pants (or coveralls), hard hat and glasses, EARPLUGS, LEATHER GLOVES, FACESHIELD 4.0 cal/cm 2 T-shirt, FR shirt & pants (or coveralls), face shield, leather gloves, earplugs, hard hat, glasses, leather shoes 8.0 cal/cm 2 Everything in 2 plus Bee Suit & Flash Suit Hood (instead of face shield) 40 cal/cm 2

28 HOW DO WE GET THERE? UNDERSTAND THE ARC FLASH HAZARD REQUIREMENTS ON A LABEL TRAIN YOUR WORKERS AND PROVIDE GEAR REQUIRE JOB HAZARD ANALYSIS AND SET ELECTRICAL SAFETY STANDARDS/RULES SELF-AUDIT CREATE LABLES (STUDY WORK)

29 DO I UNDERSTAND THE FLASH PROTECTION BOUNDARY? Arc Flash Incident Energy Arc Flash Boundary Incident Energy at the Working Distance MCC

30 DE-ENERGIZE! How is it supposed to get repaired safely? LOTO?

31 SMART UPFRONT DESIGN EQUIPMENT SELECTION ELIMINATE PARALLELING OF SOURCES DIFFERENTIAL OR FAST PROTECTION DO NOT OVERSIZE PANEL BREAKERS LOW SETTINGS ON PROTECTIVE DEVICES GROUND FAULT PROTECTION (90% FAULTS BEGIN AS SLG) ISOLATE CONTROL CIRCUITS

32 USE NEW TECHNOLOGY H L Note... Install per Manufacturer Requirements!

33 Use the right tools for the job Proper PPE Hot Sticks Properly rated hand held meters Insulated tools

34 Protect Yourself & Others That includes assessing other s abilities Make sure everyone knows the hazards Wear clothes properly You can always STOP work and ASK

35 NFPA 70E Changes

36 110.7 Electrical Safety Program (A) General. The employer shall implement and document an overall electrical safety program...

37 130.3 New last sentence and exception The flash hazard analysis shall be updated when a major modification or renovation takes place. It shall be reviewed periodically, not to exceed five years to account for changes in the electrical distribution system that could affect the results of the analysis.

38 130.3 Continued Exception: The requirements of Sections 130.7(c)(9); 130.7(c)(10) and 130.7(c)(11) shall be permitted to be used in lieu of a detailed Flash Hazard Analysis.

39 130.3 Exception [New] A flash hazard analysis is not required for circuits of 240 volts and below unless the circuit includes at least one 125kVA or larger transformer.

40 130.3 FPN [New] FPN: Improper or inadequate maintenance can result in increased opening time of the overcurrent protective device, thus increasing the incident energy.

41 130.3(A) Changed the 4 foot flash protection boundary to be based on a 2 cycle clearing time and 50kA fault current or 100kA cycles. Existing is 6 cycles and 50kA, or 300kA cycles.

42 130.3(B) The language is modified so that when work is performed within the Flash Protection Boundary, one of two methods are to be used for selecting protective clothing and other PPE. --1) Incident Energy Analysis --2) Hazard Risk Categories (Tables)

43 130.3(C) [New] Equipment Labeling. Equipment shall be field marked with a label containing the available incident energy or required level of PPE. (if required by in NEC) laminate all the tasks if using the tables

44 Table 130.7(C)(9) added Performing infrared thermography inspection task to tables.

45 130.7(C)(9) Deleted NOTES 3 and 6. Notes permitted an automatic reduction of one hazard risk category for lower short circuit currents.

46 130.7(C)(9) The 2* designation means that a flash suit hood or alternatively a face shield used in combination with a balaclava (sock hood) is required for this task...

47 Table 130.7(C)(10) Hearing Protection added to HRC 0 and 1.

48 130.7(C)(10) Requires the use of leather gloves for HRC 1.

49 Table 130.7(C)(10) Added a requirement to use either face shield or flash hood for HRC 1 with a minimum arc rating of 4.

50 210.5 FPN [New] Failure to properly maintain protective devices can have an adverse effect on the flash hazard analysis incident energy values.

51 Michelle Murphy