2008 Eaton Corporation. All rights reserved.

Transcription

1 FlashGard TM Motor Control Center Electrical Safety Hazards Design Philosophy The Product 2008 Eaton Corporation. All rights reserved. Research studies say. Five to 10 arc flash explosions occur in electrical equipment every day in the United States, according to statistics compiled by CapSchell, Inc., a Chicago-based research and consulting firm that specializes in preventing workplace injuries and deaths. Based on the incidents reported Unreported cases and near misses are estimated to be many times this number 2 2 1

2 What is an Arc Flash? An Arc Flash is a dangerous condition associated with the explosive release of energy caused by an electrical arc due to either a phase to ground or phase to phase fault. This fault can result from many factors, including dropped tools, accidental contact with electrical systems, build up of conductive dust, corrosion, and improper work procedures among others Arc Flash 3 3 What is Arc Flash Energy? It s expressed in calories per centimeter squared (cal/cm2) where Calorie (cal) Amount of thermal energy required to raise 1 gram of water s temperature 1 degree C. so Calorie/cm2 = Energy per unit of area TO GIVE YOU A PERSPECTIVE: 1 cal/cm2 = the Exposure on the tip of a finger by a Cigarette Lighter in One Second One to Two cal/cm2 will cause a 2nd Degree Burn on Human Skin 4 4 2

3 Another known fact Motor Control Centers account for the second highest frequency of electrical accidents. WHY??? MCC s 5 5 Why MCC accidents occur? MCC s are worked on more than any other electrical equipment when energized Most feel comfortable working on them live Measurements are taken daily Maintenance work is performed daily While unit is energized to avoid downtime of critical equipment or processes Or on bench but inserting and extracting the units are done live 6 6 3

4 NFPA 70E (B) Protective Clothing and Personal Protective equipment for application with a Flash Hazard Analysis Where it has been determined that work will be performed within the flash protection boundary by 130.3(A), the flash hazard analysis shall determine, and the employer shall document, the incident energy exposure of the worker (in calories per square centimeter). Flame-resistant (FR) clothing and personal protective equipment (PPE) shall be used by the employee based upon the incident energy exposure associated with the specific task. 7 7 You Have Two Options NFPA 70E, provides two methods for determining the flash hazard risk and the associated PPE to be used: 1. Generic Hazard/Risk Guideline: Defines the PPE by the specific task and exposure based on a conservative fault/energy level assessment [NFPA 70E Table 130.7(C)(9)(a)]. This Hazard/Risk Category classification table is straight forward and simple to understand

5 You Have Two Options NFPA 70E, provides two methods for determining the flash hazard risk and the associated PPE to be used: 2. Arc Flash Analysis Method: Conducting a flash hazard energy analysis to determine the actual Flash Protection Boundary and the necessary PPE. This requires data such as equipment configuration, gap between electrodes, grounding type, short circuit fault current value, system voltage on input etc. DETERMINING PPE HAZARD RISK CATEGORY Category Cal/cm2 Clothing Untreaded cotton 1 5 Flame retardant FR shirt and FR pants 2 8 Cotton underwear, FR shirt and FR pants 3 25 Cotton underwear, FR shirt, FR pants and FR coveralls 4* 40 Cotton underwear, FR shirt, FR pants and double-layer switching coat and pants * Output Categoryfor personel protective equipment (PPE) Source: NFPA 70E, Table Common Arc Flash Mythology Wearing full (CAT4) PPE for every electrical task makes electrical equipment safer Try working in PPE like this: Always shut down the Motor Control Center The best practice Sadly, this is not reality Users often find this a lengthy and costly proposition jeopardizing production

6 FlashGard Motor Control Centers Rajiv Kumar MCC Product Manager Fayetteville, NC What is Eaton s FlashGard solution? 1. Maintain a dead-front door closed while inserting or removing MCC buckets 2. Insulate and Isolate current carrying bus and components 3. With the IT. door open - limit voltages in the work area below 120 volts 4. Lower the clearing time of the upstream breaker feeding the MCC

7 What is the Eaton FlashGard? FlashGard maintains a dead-front closed door while inserting or removing MCC stabs while ALL other MCCs require the door to be OPEN!!! Standard MCC: De-energize bucket OPEN THE DOOR Disengage retention Yank bucket by hand Hope for no explosions Close door Move away hastily FlashGard MCC: De-energize bucket Insert 3/8 square drive tool or remote racking tool Withdraw MCC stabs Once visual indicators indicate lack of power and bucket shutters are closed Open the door Disengage retention walk casually away The Ultimate Design: Eaton s FlashGard MCC with RotoTract

8 What is the Eaton FlashGard? FlashGard maintains a dead-front closed door while inserting or removing MCC buckets RotoTract There is no such thing as an Arc Resistant MCC!!! Let s think about our competition s supposed Arc-Resistant offering ANSI C provides testing standards for Arc Resistant Switchgear. MCCs are NOT switchgear!!!! Switchgear must have properly latched or secured covers, doors How many MCC accidents happen with the doors and covers latched? Arc Flash with the Door Open ANSI generalizes this at CAT 3!!!

9 RotoTract Top Removed Automatic Shutters RotoTract TM Assembly EATON wins AGAIN How RotoTract works Breaker must be open to access racking tool receiver RotoTract TM prevents stripping of the mechanism or overtorquing Makes insertion of large size 4,5 buckets much safer. No more shoving buckets on to the vertical bus Internal Shutter Indicator Open Closed Bucket Position Indicator Connected Test* Withdrawn * No TEST position with Freedom

10 RotoTract TM Stab Assembly Stabs Extended Stabs Withdrawn Completely enclosed connection of the stabs to the vertical bus in combination with insulated components makes the MCC virtually Arc Free Why Keep the Door?

11 Why Keep the Door? THAT S IT!!!!! Why Keep the Door?

12 What is the Eaton FlashGard? Insulated and Isolated current carrying bus and components Labyrinth Vertical Bus Automatic Shutter RotoTract TM Stab Assembly - How it works Stabs Extended Stabs Withdrawn Completely enclosed connection of the stabs to the vertical bus in combination with insulated components makes the MCC virtually Arc Free

13 Why Shutters? Automatic Shutters provide Isolation and Insulation. Provides personal protection by isolating and insulating the live bus should a MCC unit be removed or moved to the service position, i.e., a Hazard/Risk Category reduction from Level 2* to 0 [NFPA 70E Clause 130.7(D)(1)(h), specifically Table 130.7(C)(9)(a)]. In addition, the shutters provide isolation which helps restrict an internal arc from spreading to the vertical bus [NFPA 70E Clause 130.7(D)(1)(h)] What is the Eaton FlashGard? Freedom 2100 FlashGard MCC Vertical Ground Bus CPT mounted behind device island just like any Freedom MCC bucket 120VAC Means no TEST Position in Freedom FG!

14 The Freedom FlashGard Bucket Racking Tool Receiver Power Stab Position Connected Disconnected Unit Latch Internal Shutter Position Open Closed Handle Mechanism Pilot Device Island/ Panel Start, Stop, HOA Breaker Freedom Contactor C440 SSOL Standard and Optional Features Standard RotoTract TM Assembly Labyrinth Vertical Bus Insulated Horizontal Bus Optional Bottom Plates (Stnd on NEMA 12) Vertical Bus Barrier Rodent Barrier Remote Racking Device

15 FlashGard Remote Racking Accessory Mounting Holes Remote Racking wired Accessory Accessory to perform RotoTract racking safely behind NFPA Arc Flash boundaries 120 VAC motor driven Standard Wall Plug Mounts to RotoTract Mechanism Wired pendant station for rack-in / rack-out operation. Mounting offset bracket to clear device panel FlashGard Door Accessories VoltageVision Presence or absence of voltage indicator Motor Guard Motor Guard is a patented motor testing and protection system AUTOMATICALLY monitors motor insulation breakdown

16 FlashGard Aftermarket Freedom FlashGard and IT FlashGard Freedom/ Advantage/ Five-Star MCCs - FFG Drop in to any 2100 w/ Labyrinth Vertical Bus - Non Labyrinth requires EESS Barrier retrofit