Ieee 1584 Arc Flash Hazard - Ilm (Energia Incidente)

8/10/2019 Ieee 1584 Arc Flash Hazard - Ilm (Energia Incidente)

1/21

IEEE Std 1584-2002 Arc-Flash Hazard Calculator

Site: Site Enter the site name or designation

Date: August 5, 2002 Enter the date of the analysis

Instructions for using calculator forms:1. Enter data only in yellow and blue cells.2. Information in light green and white cells is calculated.

3. If information is entered beyond the limits of the CB or fuse calculations, the protectivedevice field will change to orange as a warning flag.4. All distances are in millimeters.

5. Refer to IEEE Std 1584-2002 Annex B for guidance on application and use of thiscalculator.

Range of Models:

The equations in the IEEE Std 1584-2002 empirically derived model are valid within the

limits shown below:Voltages from 208 V to 15 kV, three phaseFrequencies of 50 or 60 HzBolted fault current from 700 A to 106 kAGrounding of all typesEquipment enclosures of commonly available sizesGaps between conductors of 13mm (.5") to 152 mm (6")Faults involving three phases


2/21

The Lee method is used for voltages over 15kV.

Cautions and Disclaimers

As an IEEE guide, this document suggests approaches for conducting an arc-flash hazardanalysis but does not have mandatory requirements. Following the suggestions in this

guide does not guarantee safety, and users should take all reasonable, independent stepsnecessary to minimize risks from arc flashes.

Users should be aware that the models in this guide are based upon measured arc currentincident energy under a specific set of test conditions and on theoretical work. Distances,which are the basis for equations, are based on the measured distance of the testinstrument from the arc-flash point source. These models will enable users to calculate theestimated maximum incident energy and the estimated arc-flash boundary distance. Realarc exposures may be more or less severe than indicated by these models.

This document is intended to provide guidance for the calculation of incident energy andarc-flash protection boundaries. Once calculated, this information can be used as a basis to

develop strategies that have the goal of minimizing burn injuries. Strategies includespecifying the rating of personal protective equipment (PPE), working deenergized,applying arc-resistant switchgear, and following other engineering techniques and workpractices.


3/21

This guide is based upon testing and analysis of the hazard presented by incident energy.The potentially hazardous effects of molten metal splatter, projectiles, pressure impulses,and toxic arc by-products have not been considered in these methods. It is expected thatfuture work will provide guidance for these other electrical hazards.

Available bolted fault currents should be determined at the point of each potential fault.

Do not use overly conservative bolted fault current values. A conservatively high valuemay result in lower calculated incident energy than may actually be possible depending onthe protective devices time-current response. The lower results would be caused by using

a faster time-current response value from the protective devices time-current curve.

Where used, PPE for the arc-flash hazard is the last line of defense. The protection is notintended to prevent all injuries but to mitigate the impact of an arc flash upon theindividual, should one occur. In many cases, the use of PPE has saved lives or preventedinjury. The calculations in this guide will lead to selection of a level of PPE that is abalance between the calculated estimated incident energy exposure and the work activitybeing performed while meeting the following concerns:

The desire to provide enough protection to prevent a second degree burn in all cases.

The desire to avoid providing more protection than is needed. Hazards may be introducedby the garments such as heat stress, poor visibility, and limited body movement.

Professional judgement must be used in the selection of adequate PPE.


4/21

While it is outside the scope of this document to mandate PPE, some examples of wherePPE may be required are: during load interruption, during the visual inspection thatverifies that all disconnecting devices are open, and during the lockout/tagout. AdequatePPE is required during the tests to verify the absence of voltage after the circuits aredeenergized and properly locked out/tagged out.

This information is based on technical data believed by the IEEE Std 1584-2002 workinggroup to be reliable. It is offered as a tool for conducting an arc-flash hazard analysis. It isintended for use only by those experienced in power system studies and is not intended tosubstitute for the users judgment or review in such studies. It is subject to revision as

additional knowledge and experience is gained. IEEE, those companies that contributedtest data, and those people who worked on development of this standard make noguarantee of results and assume no obligation or liability whatsoever in connection withthis information.

This guide is not intended to imply that workers be allowed to perform work on exposedenergized equipment or circuit parts. It must be emphasized that the industry-

recommended way to minimize electrical injuries and fatalities is to ensure that equipmentis deenergized and in an electrically safe work condition. But even this act, creating anelectrically safe work condition, subjects the worker to potential hazards, which if theyoccur, require PPE for protection against arc-flash burns.


5/21

Work intentionally performed on or near energized equipment or circuits is limited bystandards and regulations, such as those issued by OSHA. OSHA 29 CFR SubpartS.1910.333 severely limits the situations in which work is performed near or onequipment or circuits that are or may be energized.

Live parts to which an employee may be exposed shall be deenergized before the

employee works on or near them, unless the employer can demonstrate that deenergizing

introduces additional or increased hazards or is infeasible due to equipment design oroperational limitations.

Financial considerations are not an adequate reason to work on or near energized circuits.

For ready access to the specific needed flash-protection boundary, working distance, andincident energy, such calculated values should be prominently displayed on every piece ofelectrical equipment where an arc-flash hazard exists in a workplace or otherwise be madeavailable to workers.

Warranty

THE IEEE DOES NOT WARRANT OR REPRESENT THE ACCURACY ORCONTENT OF THE WORK AND EXPRESSLY DISCLAIMS ANY EXPRESS ORIMPLIED WARRANTY, INCLUDING ANY IMPLIED WARRANTY OFMERCHANTABILITY OR FITNESS FOR A SPECIFIC PURPOSE OR THAT THEUSE OF THE WORK IS FREE FROM PATENT INFRINGEMENT. THE WORK ISSUPPLIED ONLY AS IS.

USE AT YOUR OWN RISK.

Copyright

The Institute of Electrical and Electronics Engineers, Inc.


6/21

3 Park Avenue, New York, NY 10016-5997, USA

Copyright 2002 by the Institute of Electrical and Electronics Engineers, Inc.

All rights reserved. Published 23 September 2002. Printed in the United States ofAmerica.Print: ISBN 0-7381-3351-5 SH95023

PDF: ISBN 0-7381-3352-3 SS95023

No part of this publication may be reproduced in any form, in an electronic retrievalsystem or otherwise, without the prior written permission of the publisher.

IEEE Standards documents are developed within the IEEE Societies and the StandardsCoordinating Committees of the IEEE Standards Association (IEEE-SA) Standards Board.The IEEE develops its standards through a consensus development process, approved bythe American National Standards Institute, which brings together volunteers representingvaried viewpoints and interests to achieve the final product. Volunteers are not necessarilymembers of the Institute and serve without compensation. While the IEEE administers theprocess and establishes rules to promote fairness in the consensus development process,the IEEE does not independently evaluate, test, or verify the accuracy of any of theinformation contained in its standards.


7/21

Use of an IEEE Standard is wholly voluntary. The IEEE disclaims liability for anypersonal injury, property or other damage, of any nature whatsoever, whether special,indirect, consequential, or compensatory, directly or indirectly resulting from thepublication, use of, or reliance upon this, or any other IEEE Standard document.

The IEEE does not warrant or represent the accuracy or content of the material contained

herein, and expressly disclaims any express or implied warranty, including any impliedwarranty of merchantability or fitness for a specific purpose, or that the use of the materialcontained herein is free from patent infringement. IEEE Standards documents are suppliedAS IS.

The existence of an IEEE Standard does not imply that there are no other ways to produce,test, measure, purchase, market, or provide other goods and services related to the scopeof the IEEE Standard. Furthermore, the viewpoint expressed at the time a standard isapproved and issued is subject to change brought about through developments in the stateof the art and comments received from users of the standard. Every IEEE Standard issubjected to review at least every five years for revision or reaffirmation. When adocument is more than five years old and has not been reaffirmed, it is reasonable toconclude that its contents, although still of some value, do not wholly reflect the presentstate of the art. Users are cautioned to check to determine that they have the latest editionof any IEEE Standard.


8/21

In publishing and making this document available, the IEEE is not suggesting or renderingprofessional or other services for, or on behalf of, any person or entity. Nor is the IEEEundertaking to perform any duty owed by any other person or entity to another. Anyperson utilizing this, and any other IEEE Standards document, should rely upon the adviceof a competent professional in determining the exercise of reasonable care in any givencircumstances.

Interpretations: Occasionally questions may arise regarding the meaning of portions ofstandards as they relate to specific applications. When the need for interpretations isbrought to the attention of IEEE, the Institute will initiate action to prepare appropriateresponses. Since IEEE Standards represent a consensus of concerned interests, it isimportant to ensure that any interpretation has also received the concurrence of a balanceof interests. For this reason, IEEE and the members of its societies and StandardsCoordinating Committees are not able to provide an instant response to interpretationrequests except in those cases where the matter has previously received formalconsideration.

Comments for revision of IEEE Standards are welcome from any interested party,regardless of membership affiliation with IEEE. Suggestions for changes in documentsshould be in the form of a proposed change of text, together with appropriate supportingcomments. Comments on standards and requests for interpretations should be addressedto:Secretary, IEEE-SA Standards Board445 Hoes LaneP.O. Box 1331Piscataway, NJ 08855-1331


9/21

USA

Note: Attention is called to the possibility that implementation of this standard mayrequire use of subject matter covered by patent rights. By publication of this standard, noposition is taken with respect to the existence or validity of any patent rights in connectiontherewith. The IEEE shall not be responsible for identifying patents for which a license

may be required by an IEEE standard or for conducting inquiries into the legal validity orscope of those patents that are brought to its attention.

Authorization to photocopy portions of any individual standard for internal or personaluse is granted by the Institute of Electrical and Electronics Engineers, Inc., provided thatthe appropriate fee is paid to Copyright Clearance Center. To arrange for payment oflicensing fee, please contact Copyright Clearance Center, Customer Service, 222Rosewood Drive, Danvers, MA 01923 USA; +1 978 750 8400. Permission to photocopyportions of any individual standard for educational classroom use can also be obtainedthrough the Copyright Clearance Center.


10/21

Data Entry Sheet for: Normal Operation Enter description of operating mode.

Columns A-C Bus name, voltage and bolted fault current from short circuit studyColumn D Portion of bolted fault current that flows through protective device from study (at faulted bus voltage)Columns E, F, I Calculated by the spreadsheet.Column G If cell is blue, enter time-- For relay or breaker with integral trips, enter Trip Time at the Calculated Arcing

Fault Current from column F.Column H If cell is blue, enter time-- For re lay operated breaker, enter breaker Opening Time. For fuses, enter

the total clearing time at the calculated Arcing Fault Current from column F.

Column J If cell is blue, enter Trip Time for relay or breaker at the Reduced Arcing Fault CurrentColumn K If cell is blue, enter breaker opening time or fuse clearing time at the reduced arcing fault current (col I.)Column L Enter Working Distance between worker's body and the possible arcing location.Column M Enter Equipment Class from the list.Column N Enter Grounding Type from the list.Column O Enter Protective Device Type from the list. Cell turns orange if out or range or if device is CB and I tisnot entered in Col P.Column P If cell is blue, enter Instantaneous Trip current for Circuit Breakers (See CB Reference Tab)

Boundary Energy J/cm2 1.2 cal/cm2 Enter one of these values to determine arc flash boundary distan

Motor Contribution Factor: 0 Enter typical portion of bolted fault from motor contribution. Example: 0.03If you leave column D blank, motor contribution factor will be used to calculate Column E.

Name of buskV of

bus

Bolted faultcurrent of busin kA (from

study)

Portion of Bolted fault

current that flowsthrough protectivedevice in kA (from

study)

Protective device

fault currentwithout motorcontrib. in kA

(B21)

Arcing fault

current inprotectivedevice, in kA(Calculated)

TripTime

OpeningTime

Reduced arcingfault current inprotective device,

in kA

Trip TReC

CUBCULOS CARGILL 13.8 8.75 8.75 8.75 8.51 0.688 0.045 Not required

August 5 2002Site


11/21

Site: Normal OperationResults of arc flash calculations for determination of PPE and flash boundary

Bus InformationkV of

bus

BoltedFault

CurrentTotal ArcingFault Current

EquipmentClass Grounding

ProtectiveDevice

Type GapWorkingDistance

ProtectiveDevice Arc

FaultCurrent

ArcClearing

Time

ReducedCurrent

ClearingTime

IncidentEnergy

Name of Location kV kA kA 1 to 4 1 or 2 0 to 14 mm mm kA sec sec J/cm2

CUBCULOS CARGILL 13.8 8.75 8.51 1 1 0 153 610 8.51 0.73 0.00 28.46


12/21

IncidentEnergy

Arc FlashBoundary

PPE perNFPA 70E

cal/cm2 mm Category

6.8 1452 2


13/21

Site Summary of Incident Energy CalculationsIncident Energy in cal/cm2and Working Distance

August 5, 2002 NormalOperation

NormalOperation

WorkingDistance

Arc FlashBoundary

Location Voltage J/cm2 cal/cm2 mm mm

BFP-Ifp 13.8 1.9 0.4 1825.0 1112.6BFP-Ifs 0.48 219.6 52.5 610.0 7930.5BFP-Ifc2 0.48 10.6 2.5 610.0 887.8

Utility Example 68.8 61.7 14.8 1825.0 6399.5KEMA Test 8244 4.16 11.1 2.6 483.0 717.5KEMA Test 8283 4.16 101.0 24.1 610.0 13339.3SqD 28397 0.4 96.6 23.1 610.0 3697.2SqD F28 0.4 54.4 13.0 610.0 2605.2Kinectrics 2338 0.59 2.9 0.7 610.0 464.4250AMCCB 0.48 43.4 10.4 457.0 1701.92000A 0.48 25.4 6.1 457.0 1227.21000A 0.48 12.7 3.0 457.0 803.61000LI 0.48 20.2 4.8 457.0 1066.91200LI 0.48 35.1 8.4 457.0 1493.71200A Cl L 0.48 38.8 9.3 610.0 1694.7

600A RK1 0.48 19.2 4.6 610.0 1192.8enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1

enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1

enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1enter location 0.48 13.1 3.1 610.0 984.1CUBCULOS CARGILL 13.8 28.5 6.8 610.0 1452.4


14/21

Reference TablesGap and Distance Exponent Tables

kV Type Equipment Number Gap0.208 to 1 Open air 1 32

Switchgear 3 32

MCC and Panels 4 25Cable 2 13

kV Type Equipment Number Gap1 to 5 Open air 1 102

Switchgear 3 102Cable 2 13

4 102

kV Type Equipment Number Gap

5 to 15 Open air 1 153Switchgear 3 153Cable 2 13

4 153

PPE Rating Table (from NFPA 70E)

Min Rating of PPE Max Rating of PPE Risk Category0 1.2 0

1.2001 5 15.001 8 28.001 25 3

25.001 40 4

40.001 No maximum X

1 RK1-100 Class RK1 Fuse, 0A to 100 A2 RK1-200 Class RK1 Fuse, 101A to 200 A3 RK1-400 Class RK1 Fuse, 201A to 400 A4 RK1-600 Class RK1 Fuse, 401A to 600A5 L-800 Class L Fuse, 601A to 800 A6 L-1200 Class L Fuse, 801A to 1200 A7 L-1600 Class L Fuse, 1201A to 1600 A

8 L-2000 Class L Fuse, 1601A to 2000 A9 MCCB-100-400 100 to 400 ampere Molded Case CBs with all t

10 MCCB-600-1200-M 600 to 1200 ampere MCCBs with TM and M t11 MCCB-600-1200-LI 600 to 1200 ampere MCCBs and ICCBs with12 MCCB-1600-6000 1600 to 6000 ampere MCCBs and ICCBs with13 LVPCB-800-6300-LI 800 to 6300 ampere LVPCBs, LI trip units14 LVPCB-800-6300-LS 800 to 6300 ampere LVPCBs, LS trip units

CB Equation Constants Table (E = k1 * Ibf + k2)

Protective Device Type Descriptions


15/21

Device Type 480V& lower, K1 480V&lower, K2 600V K19 0.045 0.13 0.065

10 0.053 0.38 0.0811 0.09 0.324 0.11212 0.107 0.72 0.16413 0.15 0.88 0.23

14 1.09 6.51 1.64

Fuse Equation Lower Limits Table

Device Type Lower Limit of Ibf 1 0.652 1.163 3.164 8.55 15.76 15.77 15.78 22.6

Fuse Equation Constants Table (E = K1 * Ibf^2 + K2 * Ibf + K3)

Device Type Ibf from Ibf to K11 0 0.649999 01 0.65 1.16 01 1.160001 1.4 01 1.400001 106 01 106.000001 1000 02 0 1.159999 02 1.16 1.6 02 1.600001 3.16 02 3.160001 106 0

2 106.000001 1000 03 0 3.159999 03 3.16 5.04 03 5.040001 22.6 03 22.600001 106 03 106.000001 1000 04 0 8.499999 04 8.5 14 04 14.000001 15.7 04 15.700001 22.6 04 22.600001 106 04 106.000001 1000 0

5 0 15.699999 05 15.7 44.1 05 44.100001 106 05 106.000001 1000 06 0 15.699999 06 15.7 22.6 06 22.600001 44.1 0.01436 44.100001 106 06 106.000001 1000 0


16/21

7 0 15.699999 07 15.7 31.8 07 31.800001 44.099999 07 44.1 65.9 07 65.900001 106 07 106.000001 1000 0

8 0 22.599999 08 22.6 65.9 08 65.900001 106 08 106.000001 1000 0

Note A: Must change to device type 0 if bolted fault current is below lower limit;Note B: Contact manufacturer for additional information above upper limit.


17/21

X2

1.473

1.6412

X2

0.9732

0.973

X

20.973

20.973

rip unitsip unitsI electronic trip unitsLI, TM or M trip units


18/21

600V K20.040.09

110.040.07

0.519

K2 K30 Note A

-11.176 13.565-1.4583 2.2917

0 0.250 Note B0 Note A

-18.409 36.355-4.2628 13.721

0 0.25

0 Note B0 Note A

-19.053 96.808-0.0302 0.9321


-3.0545 43.3640 0.6

-0.0507 1.39640 0.250 Note B

0 Note A-0.0601 2.8992


-0.1928 14.226-1.3919 34.045

0 0.390 Note B


19/21

0 Note A-0.1863 27.926-1.5504 71.303

0 2.93-0.0631 7.0878

0 Note B

0 Note A-0.1284 32.262-0.5177 57.917

0 Note B

use time-current curves.


20/21

Circuit Breaker Reference Information

This sheet provides a simple method for making the calculations where low-voltage CBs provideovercurrent protection. The method covers molded-case circuit breakerss (MCCBs), insulated-casecircuit breakers (ICCBs) and low-voltage power circuit breakers (LVPCBs). Generic informationcovering the time-current characteristic of CBs is contained within the method. This inclusion

eliminates the need for the individual performing the calculation to find and interpret the CB time-current curve. The CBs selected for this analysis are those that have been generally available fromapproximately 1980 - 2001.

The variables used in this sheet are:I1 - the lowest arc current at which the CB clears a fault at the instantaneous-clearing timeI2 - the CB interrupting rating in kAIt - current at which the CB trips instantaneously (without intentional delay) in kA

A. Circuit Breaker Performance Range

Equations in this method provide the maximum estimated energy between fault current points I1 and I2.

As we have stated, point I2 is the interrupting rating of the CB. I1 is the minimum arcing fault current atwhich this method can be applied. It is the lowest bolted fault current level that generates arcing currentgreat enough for instantaneous tripping to occur. Recall that the current flowing is the arc current,which is lower than the available bolted fault current.

To find I1, use the manufacturers time-current curve if it is available and take the instantaneous tripvalue, It, from the curve as shown in Figure 1 and insert it in Column P. If the curve is not available,

but the instantaneous trip setting is shown on the breaker, use that setting. Alternatively, the defaultvalue noted in B below must be used. Where an LS trip unit is used, It is the short-time pick-up current.

Figure 1 ItShown on Time-Current Characteristic

B. It Default ValueWhen the tripping current, It, is not known, use a default value of 10 times the continuous current ratingof the CB, except for CBs rated 100 A and below. For CBs rated 100 A and below, use a default valueof It = 1300 A.

I1 = 10^[0.0281 + 1.09 Log((1.3 It)] at 600 V and, (Eq. 5) I1 = 10^[0.0407 + 1.17 Log((1.3 It)] at 480 V and lower.} (Eq. 6)

Typical time-current characteristic

0.01

0.1

1

10

100

1000

10000

100 1000 10000 100000

Current

Time(sec)

It


21/21

Spreadsheet compares I1 to Bolted Fault current; if I1Ib, then the CB equations are not used to calculate incidentenergy.

Ieee 1584 Arc Flash Hazard - Ilm (Energia Incidente)

Documents

Transcript of Ieee 1584 Arc Flash Hazard - Ilm (Energia Incidente)