6/4/2017. Advances in technology to address safety. Thomas A. Domitrovich, P.E., LEED AP VP, Technical Sales Eaton

Transcription

1 Advances in technology to address safety Thomas A. Domitrovich, P.E., LEED AP VP, Technical Sales Eaton 1

2 Advances in technology could mean use existing technology & back to basics Advances in safety are often driven by Codes and Standards Our library continues to grow! 2

3 Working de energized is a journey The journey begins with energized work Maintenance Reducing Time Reducing Current Shock, Arc Flash, Arc Blast Adding Barriers Adding Distance 3

4 Current & Time Two key parameters in our story of incident energy and shock + Current Time Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current time we permit current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with energized conductors Adding Distance 4

5 Reducing Time Reduced clearing times can protect a person from shock The severity of the shock is affected by three primary factors Magnitude Amount of current flowing through the body, influenced both by the magnitude of the driving voltage and the total resistance of the path that current takes though your body Path The path of the current through the body Current that flows through your chest cavity is more likely to cause harm than current that flows through an extremity Time Length of time the body is in the circuit. 5

6 The severity of the shock is affected by three primary factors Magnitude Amount of current flowing through the body, influenced both by the magnitude of the driving voltage and the total resistance of the path that current takes though your body We CAN control the amount of time current is permitted to flow Time Length of time the body is in the circuit. The severity of the shock is affected by three primary factors Electronics will continue to change our landscape 6

7 UL Curve Defining Performance Tripping Of A GFCI Device UL 943 People Protection Ground Fault Circuit Interrupters Pickup Up From 4 6 ma Trip time ~15 ms UL 1053 Equipment Protection GF Sensing & Relaying Equipment Leakage within 10% of level defined by manufacturer 7

8 Ground Fault Protection of Equipment. A system intended to provide protection of equipment from damaging line to ground fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit. This protection is provided at current levels less than those required to protect conductors from damage through the operation of a supply circuit overcurrent device. Ground Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel that functions to de energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device. Informational Note: Class A ground fault circuit interrupters trip when the current to ground is 6 ma or higher and do not trip when the current to ground is less than 4 ma. For further information, see UL 943, Standard for Ground Fault Circuit Interrupters. Reducing Time Reducing the time that arcing current is permitted to flow reduces incident energy 8

9 Reducing Time Reducing the time that arcing current is permitted to flow reduces incident energy An Arc Flash Is The Light, Heat, Sound And Gases Produced As A Result Of A Rapid Release Of Energy Due To An Arcing Fault Sustained By The Establishment Of A Highly Conductive Plasma. 9

10 Bolted Fault Arcing Fault Systems must be designed for worst case conditions However, the majority of faults will be arcing type The Amount of Energy Released Is Based on The Amount of Current and Time Arcing fault basics Arcing Fault 3.2 arcing fault current: A fault current flowing through an electrical arc plasma, also called arc fault current and arc current IEEE Std IEEE Guide for Performing Arc Flash Hazard Calculations 10

11 Bolted Fault Current (ka) Arcing Current (ka) V, Panelboard, Solidly Grounded System IEEE 1584, IEEE Guide for Performing Arc Flash Hazard Calculations 85% Arcing Current (ka) Bolted Fault Current (ka) Arcing Current (ka) V, Panelboard, Solidly Grounded System IEEE 1584, IEEE Guide for Performing Arc Flash Hazard Calculations 85% Arcing Current (ka) 11

12 Time In Seconds Long Time Pickup Long Time Delay Short Time Pickup Short Time Delay (I2t) The Time Current Characteristic (TCC) Curve Instantaneous Pickup Three Regions Long time: Opening in minutes Short time: Opening in seconds or tenths of seconds. Instantaneous: Opening with no intentional delay Multiples of Rated Current Molded Case Circuit Breakers Miniature G Frame E Frame F Frame J Frame K Frame L Frame M Frame N Frame R Frame A A A A A A A A A A Continuous Ampere Ratings from 15A to 2500A Frame Interrupting Capabilities of 10kA to 100kA Industrial AND Residential Applications Typically fixed mounted and no maintenance capabilities (must be replaced). 12

13 MCCB Time Current Curves Fixed Instantaneous Adjustable Instantaneous MCCB Time Current Curves Instantaneous Pickup Values Fixed Instantaneous pickup values can range from 10X Rating to more than 20X rating of the breaker Fixed Clearing Time 0.01 to 0.02 s Adjustable clearing 0.05 s 13

14 Insulated Case Circuit Breakers Ampacity Ratings (800A 6000A) Interrupting Ratings (35 150kA) High instantaneous override and short time delay for increased coordination ICCB Time Current Curve Exercise Adjustability 14

15 ICCB Time Current Curve Exercise Instantaneous pickup values typically 12X the frame ratings not the long time pick up rating Fixed Clearing Time 0.02 sec Adjustable clearing 0.06 sec Adjustability Low Voltage Power Circuit Breakers Amp Ratings (800A 4000A) Interrupting Rating from 42kA to 100kA and Current Limiting Up To 200kA 15

16 LVPCB Time Current Curve LVPCB Time Current Curve Instantaneous can be turned OFF Short Time Delay can be upwards of 30 Cycles (0.48 Seconds) 16

17 Fuse Key data point is where the fuse crosses 0.01s Clearing times beyond that point are 0.1s and faster Time (Seconds) Minimum Melt Total Clear A Fuse Opens At Some Time Between These Bands Current (Amps) Fuse The point at which the fuse crosses 0.01s varies by fuse and amp rating 9 17X rating up to 600A X rating 601A to 4000A Time (Seconds) Minimum Melt Total Clear Current (Amps) A Fuse Opens At Some Time Between These Bands 17

18 Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 10 ka Short Circuit current 4.35 ka Arcing current rating Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 20 ka Short Circuit current 7.08 ka Arcing current rating 18

19 Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 30 ka Short Circuit current 9.41 ka Arcing current rating Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 40 ka Short Circuit current ka Arcing current rating 19

20 Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 50 ka Short Circuit current ka Arcing current rating Arc Clearing Time (Sec) Incident Energy Cal/cm V Panelboard Bus 80 ka Short Circuit current ka Arcing current rating 20

21 Technologies that reduce clearing times of circuit breakers Arc reduction maintenance switch Zone selective interlocking Differential relaying Arc extinguishers Current limiting fuses Being in the zone depends on technology The following technologies rely on a fault location between two devices Zone selective interlocking Differential relaying Active arc flash mitigation systems Isc Zone of protection Zone of protection assumes no lineside propagation 21

22 Being in the zone depends on technology Isc The following technologies provide reduced clearing times for currents downsream of the device Arc reduction maintenance switch Circuit breaker instantaneous Fuse Zone of The arcing current must be greater than the pickup value protection Zone of protection assumes no lineside propagation Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current time we permit current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with energized conductors Adding Distance 22

23 Adding Barriers Adding barriers helps reduce the chance of inadvertent contact which can lead to arc flash events The severity of the shock is affected by three primary factors We can t control the path that current takes through the body Path The path of the current through the body Current that flows through your chest cavity is more likely to cause harm than current that flows through an extremity 23

24 NEC & UL Changes NEC 2017 UL 67 Standard for Safety Panelboards Product standard Impacts new products not those on the shelf NEC 408.3(A) Installation requirement Impacts new installations 408.3(A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard NEC 2017 Shock protection for personnel Protection from energized components when main is turned off New for NEC 2017 now includes panelboards UL changes impact product made 1/1/2017 and later 24

25 408.3(A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard Shock protection for personnel Protection from energized components when main is turned off NEC (A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard NEC

26 408.3(A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard NEC (A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard NEC

27 6/4/ (A)Conductors and Busbars on a Switchboard, Switchgear, or Panelboard NEC

28 Finger Safe Solutions Simple Yet Powerful! Finger safe designs preventing accidental contact with energized fuse clips Indicating LED providing clear indication on which fuse has opened. 28

29 Isolate Energized Parts Simple Yet Powerful! Double door line isolation switch Isolate fuses from line side power Visible blades provides clear indication Interlocked to prevent opening energized Visual voltage indicators Simple Yet Powerful! Yet another way to visually see voltage Viewing window visible blades Line and load side indicators 29

30 Through the door Simple Yet Powerful! Panel mount through the door for replacement with the door closed 30

31 Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current time we permit current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with energized conductors Adding Distance Reducing the arcing current could increase clearing times while also addressing proper equipment ratings Reducing Current 31

32 The severity of the shock is affected by three primary factors Magnitude Amount of current flowing through the body, influenced both by the magnitude of the driving voltage and the total resistance of the path that current takes though your body Magnitude is determined by the impedance of the circuit Time Length of time the body is in the circuit. Interrupting Rating NEC 110.9: Device interrupting rating MUST be equal to or greater than the maximum available fault current. Demonstrations (Miss Applied OCPD Devices) 10,000 AIR, 600V, Class H Fuse, 50,000A Available 14,000 AIR, 480V, Circuit Breaker, 50,000A Available 32

33 Short Circuit Current Rating (SCCR) Select Current Limiting devices 33

34 Current Limitation Approximately 26,000A Short Circuit: 90 ft 2/0 AWG, 1 Cycle Clearing Time Current Limitation Approximately 26,000A Short Circuit: 90 ft 2/0 AWG, Less than 1/2 Cycle Clearing Time 34

35 Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current time we permit current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with energized conductors Adding Distance Place the worker out of harms way through use of technology Adding Distance 35

36 Remote monitoring / control Remote Monitoring: Enables Troubleshooting, Diagnostics without Opening Enclosures Remote monitoring of voltage, current levels reduces exposure to electrical hazards Displays on enclosure exteriors or computer port on exterior or networked Open circuit breakers remotely Remote monitoring / control Remote Monitoring: Enables Troubleshooting, Diagnostics without Opening Enclosures Software applications do more than help save energy and improve power quality. Where equipment is located Power flow for complex lock out tag out procedures Remote opening of switches and other devices 36

37 Robots can be leveraged through umbilical cord use to place the worker outside of the arc flash boundary Small molded case switches and circuit breakers are also addressed by remote operated devices 37

38 Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current time we permit current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with energized conductors Adding Distance 38

39 Maintenance Maintenance is important to safety on many fronts including Maintenance Reducing Time Adding Barriers Reducing Let s talk about reducing the Current Maintenance time we permit is current to flow and preventing Shock, Arc Flash, Arc Blast incidental contact with on many energized fronts conductors important to safety including Adding Distance 39

40 Early detection and avoid the flash Prevent Fault Monitor Insulation Integrity Early detection and avoid the flash Prevent Fault Infrared Scanning Windows for LV/MV Assemblies 40

41 System and component health Operations # of fault current interruptions Maintenance schedules Our Safety Journey Continues 41

42 Thank You! Advances in technology to address safety Thomas A. Domitrovich, P.E., LEED AP VP, Technical Sales Eaton 42