ML20209F649
| ML20209F649 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/14/1985 |
| From: | Hight G, Faith Johnson, Mcmicken S WYLE LABORATORIES |
| To: | |
| Shared Package | |
| ML20209F636 | List: |
| References | |
| 47193-1, 47193-1-RA, NUDOCS 8507120511 | |
| Download: ML20209F649 (11) | |
Text
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REVISIONS aEvision. 4 REPORT NO. 47193-1 - l 1
g DATE: June 14, 1985 LASONATOfufS SCIENTIFC SERvCES & SYSTEMS GROUP ,
REV NO. DATE PAGE OR PARAGRAPH AFFECTED BY APP'L DESCRIPTION OF CHANGES A 6/14/85 title, iv, v, vi, vii, viii, SMM Mh) )5angetitle;extendqualifica-I-1, III-4, III-27 through ,(([$$ontoallcoilsinstation; III-32 $jhmplifyagingcalculationsand
@ 105 class coils.
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Test Report
, , . , , REPORT NO. 47193-1, REVISION A
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47193 ik WYLE JOB NO.
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PAGE REPORT 2 ~. i DATE February 7,1985 3
d SPECIFICATION (S)
SUMMARY
Motor Control Center contactor coils, described in Paragraph 6.0, were subjected to an extreme service conditiona test after receiving thermal equivalent lives of 10 , 20 , and 40-years.
This test program was performed to determine the ability of contactor coils rated at 115 VAC (+10 percent) to operate continuously at 138 VAC (120 percent rated voltage).
Testing was performed to determine contac;or operability on specimens having thermal ages ranging from 10 through 40 years, depending on application.
' (DN330)
STATE OF ALABAMA g "' Alabama Professional Eng. ,,%, '
C3UNTY OF MADISON Reg. No. 13475 L'**O '" *"'"* ",%",",,',"1",c1lic PREPARED BY L*785 Gerald R. Carbonneau .W % m . M. M deposee and nye: The informatu contei n ime report is the reeun of compiele APPROVEDB
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G. Wayne Higljt /
Notary Rbblic in and for the State of Alabama et large.
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/ LABORATORIES SCIENTIFIC SERVICES & SYSTEMS GROUP HUNTSVILLE, ALABAMA
REVISION A TEST PROGRAM TO DETERMINE TliE EFFECTS OF CONTINUOUS 120 PERCENT RATED VOLTAGE ON MOTOR CONTROL CENTER A CONTACTORS DURING NORMAL AND EXTREME SERVICE CONDITIONS l
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for l.___.
Virginia Electric Power Company 700 East Franklin Street Richmond, Virginia 23219
O i Page No. iv Test Report No. 47193-1 -REVISION A
,. 4.0
SUMMARY
(Continue @
NOA Report Report Date Description Section testing continued. As a result of this anomaly, only coils with a 10-year or less equivalent life could be qualified due to repeated failures of coils with equivalent i
lives in excess of 10 years. The failure of Specimen 44.6 limited qualification of Size 4 coils to those with an equivalent life of 35.08 years or less.
5 10/23/84 Documents the failure of a seventh Size 1 VIII coll, Specimen 41.6, with 115 percent of rated voltage applied to the coil during Extreme Service Conditions testing. This anomaly affected the test program in that it limited qualification of Size 1 coils to 10.03 years.
Size 1 coils having a 13.54 year 'or more equivalent life exhibited repeated failures (see Notlees of Anomaly 4 and 5). Therefore, the Size 1 coils could not be quallfled for 13.54 years or greater since it was judged that the failures of the i Size 1 specimens were common mode. The Size 1 coils did demonstrate sufficient integrity to perform their safety-related functions up to and including the 13.15 year equivalent life point with voltages up to and including 117 percent 1
f of rated voltage at a 100 percent duty cycle in the environment specified in Paragraph 2.0 of Section X.
i The Size 4 coils exhibited sufficient integrity to perform their safety-related functions up to and including a 35.08 year equivalent life at voltages up to and
! including 117 percent of rated and 100 percent duty cycle in the environment specified in Paragraph 2.0 of Section X. It was judged that the failure of the Size 4 coil, Specimen 44.6, was a common mode failure. Therefore, qualification '
- j. of Size 4 coils is limited to 35.08 years.
j i The following table presents a breakdown of the test specimens and their A equivalent Ilves due to thermal aging. The lives are for coil duty cycles of 20 i percent, 50 percent, and 100 percent. The disparity in the equivalent thermal lives of the 40-year specimens is because these coils were aged to simulate forty years at the different overvoltage settings shown in Paragraph 6.0; these differing aging times resulted in the lives tabulated below for the worst-case overvoltage (115 percent for Size 1 coils and 117 percent for Size 4 coils). Also, coil status at the end of the test program as to whether it passed or failed is presented. Methodology used to compute the equivalent lives is contained in Appendix V of Section III.
4 WYLE LABORATORIES Huntsville Facihty 1
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Page No. v
. Test Report No. 47193-1 REVISION A 400
SUMMARY
(Continued)
Equivalent Equivalent Equivalent A Life at 20% Life at 20% Life at 20%
Duty Cycle Duty Cycle Duty Cycle with Worst-Case with Worst-Case with Worst-Case Specimen Specimen Overvoltage Overvoltage Overvoltage (Passed No. Applied Applied Applied or Failed)
SIZE 1 COILS 11.1 43.04 18.29 .10.03 Passed 11.2
- N/A N/A Failed 1 21.1 55.91 24.34 13.78 Passed 21.2 55.28 23.71 13.15 Passed 41.1
- N/A N/A Failed 2 41.2
- N/A N/A Failed 3 41.3 59.70 28.13 17.57 Failed 4 41.4 55.67 24.10 13.54 Failed 4 41.5 55.91 24.34. 13.78 Failed 4 41.6 55.91 24.34 13.78 Failed 5 SIZE 4 COILS 14.1 39.52 17.45 10.02 Passed 14.2 39.52 17.45 10.02 Passed 24.1 79.91 35.08 20.01 Passed 24.2 79.91 35.08 20.01 Passed 44.1 87.59 40.42 24.55 Passed 44.2 87.59 40.42 24.55 Passed 44.3 110.30 49.88 29.57 Passed 44.4 145.48 62.90 35.08 Passed 44.5 174.37 73.84 40.02 Passed 44.6 178.90 74.98 40.03 Failed 4 Specimen failed during thermal aging. See discussion in Section III.
1 See Notice of Anomaly 1.
2 See Notice of Anomaly 2. ;
3 See Notice of Anomaly 3. I See Notice of Anomaly 4.
4 5 See Notice of Anomaly 5.
l Worst-case overvoltage was 115 percent for Size 1 coils and 117 percent for Size A !
4 coils. I l
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WYLE LABORATORIES Huntsville FacHity
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Page No. vi Test Report No. 47193-1 REVISION A
5.0 REFERENCES
5.1 Virginia Electric Power Company Purchase Order No. 739705.
5.2 Wyle Laboratories' Quotation No. 543/1782/WB.
5.3 Wyle Laboratories' Test Procedure 47193, Rev C.
5.4 Wyle Laboratories' (Eastern Operations) Quality Assurance Program Manual.
5.5 U.L. Standard 508, " Industrial Control Equipment."
5.6 IEEE Standard 649-1930, "IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations."
6.0 TEST SPECIMEN DESCRIPTION The er it to be qualified was coils installed in motor control center contacta A
_d relays used in Virginia Electric and Power Company's North Anna Power Stat.ons.
Contactors and relays having the following model numbers are installed in North A
Anna Power Stations; also listed is the model number of the required coll.
Maximum Part Motor HP Coil Number Device at 460 VAC Part Number DIL 00L Universal Relay N/A J-DIL 00b-NA DIL 00b Universal Contactor 5 J-DIL 00b-NA DIL 00-52 Universal Contactor 3 (at 230 VAC) J-DIL 006-NA DIL 00Lb-22 Universal Relay N/A J-DIL 00b-NA DIL 0-11 Universal Contactor 10 J-DIL Oa-NA DIL 0-52 Universal Contactor 10 J-DIL Oa-NA DIL 2-22 Universal Contactor 40 J-DIL 2-NA DIL 3-22 Universal Contactor 60 J-DIL 3-NA DIL 4-22 Universal Contactor 100 J-DIL 4-NA DIL 6-22 Universal Contactor 150 J-DIL 6-NA DIL 8-22 Universal Contactor 200 J-DIL 8-NA The equipment tested consisted of 10 Size 1 coils,10 Size 4 colh, and 1 Size 6 coil (Temperature Rise Measurement Test only). Each specimen wu installed in the appropriate size Klockner-Moeller contactor for all testing in accordance with Paragraph 1.3 of Section X of this report.
WYLE LABORATORIES Huntsyme Facility
l Paga No. vil Test Report No. 47193-1 REVISION A 8.0 TEST SPECIMEN DESCRIPTION (Continued)
Test Specimen No. Part No. Description 11.1 J-DIL Oa-NA Size 1 coll,10-year specimen,115% rated voltage 11.2 J-DIL Oa-NA Size 1 coil,10-year specimen,115% rated voltage 21.1 J-DIL Oa-NA Size 1 coil,20-year specimen,115% rated voltage 21.2 J-DIL Oa-NA Size 1 coil, 20-year specimen,115% rated voltage 41.1 J-DIL Oa-NA Size 1 coil,40-year specimen,110% rated voltage 41.2 J-DIL Oa-NA Size 1 coil,40-year specimen,110% rated voltage 41.3 J-DIL Oa-NA Size 1 coil,40-year specimen,112.5% rated voltage 41.4 J-DIL Oa-NA Size 1 coil,40-year specimen,117% rated voltage 41.5 J-DIL Oa-NA Size 1 coll,40-year specimen,115% rated voltage 41.6 J-DIL Oa-NA Size 1 coil,40-year specimen,115% rated voltage 14.1 J-DIL 4-NA Size 4 coil,10-year specimen,117% rated voltage 14.2 J-DIL 4-NA Size 4 coil,10-year specimen,117% rated voltage 24.1 J-DIL 4-NA Size 4 coil,20-year specimen,117% rated voltage 24.2 J-DIL 4-NA Size 4 coil,20-year specimen,117% rated voltage 44.1 J-DIL 4-NA Size 4 coil,40-year specimen,110% rated voltage 44.2 J-DIL 4-NA Size 4 coil,40-year specimen,110% rated voltage 44.3 J-DIL 4-NA Size 4 coll,40-year specimen,112.5% rated voltage 44.4 J-DIL 4-NA Size 4 coil,40-year specimen,115% rated voltage 44.5 J-DIL 4-NA Size 4 coil,40-year specimen,117% rated voltage 44.6 J-DIL 4-NA Size 4 coil,40-year specimen,117% rated voltage 6.1 J-DIL 6-NA Size 6 coil Materials used to construct all coils are identical; equal size or smaller coils are assumed to qualify larger coils by virtue of their equal or higher heat rises.
Thus, J-DIL Oa-NA coils qualify those up through the J-DIL 3-NA coll; others are qualified by the J-DIL4-NA coils. Temperature rise measured on the J-DIL 6-NA coil (see Section I) was the same, within experimental error, as that measured on the J-DIL 4-NA coil.
All test specimens were permanently marked with the complete specimen number for identification throughout the test program. The specimen number consisted of a 2-digit number to identify the specimen as to thermal age and coil i
size and a decimal 1-digit number to identify the specimen among others of the
' same size and age (e.g., Specimen 44.2, 40-year specimen, Size 4 coil number 2 i of 6). The specimens were also tagged with Quality Assurance " Test Specimen" -
tags upon receipt at Wyle Laboratories.
7.0 QUALITY ASSURANCE All work performed on this test program was conducted in accordance with Wyle Laboratories' Quality Assurance Program which complies with the applicable '
requirements of 10 CFR 50 Appendix B, ANSI N 45.2, and the " daughter" >
standards. Defects are reported in accordance with the requirements of 10 CFR 21.
WYLE LABORATORIES Huntsville Facility
Page No. viii Test Report No. 47193-1 REVISION A -
l i
810 TEST EQUIPMENT AND INSTRUMENTATION
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All instrumentation, measuring, and test equipment used in the performance of this test program were calibrated in accordance with Wyle Laboratories' Quality Assurance Program which complies with the requirements of Military i Specification MIL-STD-45662. Standards used in performing all calibrations are traceable to the National Bureau of Standards by report number and date. When no national standards exist, the standards are traceable to international standards or the basis for calibration is otherwise documented and auditable.
9 WYLE LABORATORIES Huntsville Facihty
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Page No. I-1 Test Report No. 47193-1 REVISION A
- SECTION I TEMPERATURE RISE MEASUREMENT 1.0 REQUIREMENTS Coil temperature rise shall be measured on one of each of the following sizes of contactors: 1,4, and 6. Temperature rise shall be measured per U.L. STD 508 with 110 percent,112.5 percent,115 percent,117 percent, and 120 percent of rated voltage (115 VAC) applied to the coll.
It should be noted that the temperature rises specified in Table 50.1 of UL A Standard 508,14th edition, represent the maximum allowed to attain UL qualification, it does not imply a 40-year environmental qualification. Thus, a class 105 coil can have any heat rise less than or equal to 850C; conservatism
.would require assuming 8500 unless actual measurements prove otherwise.
210 PROCEDURE 2,1 Test Specimen Identification An inspection was performed upon receipt of the test specimens at Wyle Laboratories. This inspection verified that the equipment was as described in Paragraph 6.0 of the introduction section. The test specimens were tagged with Quality Assurance " Test Specimen" tags and permanently marked with a specimen number to facilitate identification throughout the test program.
2,2 Test Setup The three test specimens (Item 21.1, Item 24.1, and Item 6.1) were wired for temperature rise measurement as shown in Figure 1 of Section X.
l 2,3 Temperature Rise Measurement The test specimen coils were Installed in the appropriate contactors and three thermocouples were mounted within three to six feet of the specimens.
Temperature rise was then measured using the following procedure.
- 1. Using a DMM (digital multimeter), the coil resistance of each of the three contactor coils was measured and recorded on Data Sheets.
- 2. Contactors were connected as shown in Figure 1 of Section X.
- 3. 120 VAC power was applied to the circuit.
- 4. Voltage was adjusted to 126.5 (10.5 percent) VAC (110 percent rated).
- 5. Monitoring and recording of ambient temperature on the datalogger commenced.
- 6. The three " Start /Stop" switches were closed, timing on the coils commenced, and voltage was readjusted to 126.5 (10.5 percent) VAC.
WYLE LABORATORIES Huntsville Facility
l Page No. I-2
. Test Report No. 47193-1 2.0 PROCEDURE (Continued) 2.3 Temperature Rise Measurement (Continued)
- 7. Coil current at intervals of 10 percent cf the previously elapsed duration of the test but not less than 10-minute intervals was measured and recorded.
- 8. At i hour of test . duration and continuing throughout the test, the last 3 successive current values were ecmpared. If the 3 values were within +1 -
percent of the mid-value current, step 10 was performed; if not, step 7 was continued.
- 9. A stopwatch was prepared to start timing when the " Start /Stop" switch associated with the particular coil in question was opened.
- 10. A DMM set to measure voltage was connected across the coil to be de-energized.
- 11. The " Start /Stop" switch on the_ temperature-stabilized coils was opened and the stopwatch started. The DMM was shifted to the resistance scale and the voltmeter voltage was adjusted to 126.5 (10.5 percent) VAC.
- 12. Coil resistance was measured and recorded using the DMM at 5 seconds,10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds,1 minute, 2 minutes,5 minutes, and 10 minutes following de-energization.
- 13. If other coils remained energized, testing returned to step 7.
- 14. Coils were allowed to cool to room temperature (coil resistance was either within +10 percent of last ambient value measured in step 1 or 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> had elapse ( whichever occurred first).
- 15. Steps 1 through 14 were repeated at a coil voltage of 129.38 (10.5 percent)
VAC (112.5 percent rated).
- 16. Steps 1 through 14 were repeated at a coil voltage of 132.25 (10.5 percent)
VAC (115 percent rated).
- 17. Sceps 1 through 14 were repeated at a coil voltage of 134.55 (10.5 percent)
VAC (120 percent rated).
- 18. Steps 1 through 13 were repeated at a coil voltage of 138 (10.5 percent)
VAC (120 percent rated).
- 19. The measured resistance was plotted as a function of time elapsed since de-energization of the coil. The curves obtained were extrapolated backward to obtain the coil resistance when energized (time zero). ,
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WYLE LABORATORIES Huntsyme Facthty
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Page No. III-3 Test Report No. 47193-1 3.0 RESULTS The test specimens were thermally aged as described in Paragraph 2.0 and successfully met the requirements of Paragraph 1.0 with the three following anomalies noted.
The first anomaly (see Notice of Anomaly 1 in Appendix I) dealt with the failure of a Size 1 coil, Specimen 11.2, 152.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br /> into thermal aging at 1200C and powered with'115 percent of rated voltge. The bobbin material in the coil was deformed due to heat from thermal aging (see Photographs III-2 and III-3 in Appendix II). This prevented the coil from pulling the contactor in, resulting in excessive current flow, overheating, and subsequent failure of the coil. This failure was not judged to have an impact on the test program because the coil was aged under temperatures that would not be experienced under normal service conditions and which exceeded coil design limitations. The coil was removed from the test program, and testing resumed with the client's concurrence.
The second anomaly (see Notice of Anomaly 2 in Appendix I) dealt with the failure of a second Size 1 coil, Specimen 41.1, 262 hours0.00303 days <br />0.0728 hours <br />4.332011e-4 weeks <br />9.9691e-5 months <br /> into thermal aging at 1200C and powered with 115 percent of rated voltage (see Photograph III-4 in Appendix II). The coil magnet wire insulation broke down, lowering coil resistance. This resulted in excessive current flow and overheating of the coll.
This failure was judged to have no impact on the test program because the aging temperature exceeded normal service conditions and exceeded coil design limitations. The client dictated that, should a third Size 1 coil fail during thermal aging, all Size 1 coils were to be removed from aging and their equivalent life to that point be calculated. The coil was removed from the test program and testing resumed with the client's approval.
The third anomaly (see Notice of Anomaly 3 in Appendix I) dealt with the failure of a third Size 1 coll, Specimen 41.2, 813.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> into thermal aging at 1200C and powered with 115 percent of rated voltage. The coil shorted and burned due to heat from excessive current flow (see Photograph III-5 in Appendix II).
Because the coils were aged under conditions which exceeded coil design limitations, the failure of the third coil resulted in the removal of all Size 1 coils from thermal aging. Their equivalent lives to that point were calculated per i Notice of Anomaly 2 and are presented in Notice of Anomaly 3.
- The equivalent lives of the specimens at various duty cycles provided by the l
client were also calculated and are presented in the following table.
WYLE LABORATOMES Huntsville Facility
)1 Page No. III-4 Test Report No. 47193-1 REVISION A 3.8 RESUL'IB (Continue 4 EQUIVALENT LIVES OF CONTACTOR COILS FOLLOWING THERMAL AGING AT OR BELOW 117 PERCENT OF RATED VOLTAGE Equivalent Life at Equivalent Life at Equivalent Life at Specimen No. 20% Duty Cycle (Yrs)S0% Duty Cycle (Yrs)100% Duty Cycle (Yrs) 11.1 43.04 18.29 10.03 11.2 Failed 1 21.1 55.91 24.34 13.78 21.2 55.28 23.71 13.15 41.1 Failed 2 41.2 Failed 3 41.3 59.70 28.13 17.57 41.4 55.67 24.10 13.54 41.5 55.91 24.34 13.78 41.6 55.91 24.34 13.78 1 See Notice of Anomaly 1.
2 See Notice of Anomaly 2.
3 See Notice of Anomaly 3.
Photographs m-1 through m-5 are presented in Appendix II. Photograph m-1 shows the test specimens in the thermal aging chambers and Photographs M-2 through m-5 show coils that failed during thermal aging.
Figures M-1 through m-3 are presented in Appendix m. Figures m-1 and III-2 show the wiring diagrams for the Size 1 and Size 4 coils. Figure III-3 presents a typical circular chart from the aging chamber.
Data Sheets and Instrumentation Equipment Sheets are presented in Appendix IV.
Methodology used to determine thermal equivalent lives is presented in Appendix A V.
I 1
WYLE LABORATORIES Huntswile Facility k
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Pagn No,III-27 Test Report No. 47193-1 REVISION A APPENDIX V METHODOLOGY USED TO DETERMINE THERMAL EQUIVALENT LIVES 1
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l WYLE LABORATORIES Huntsville Facility
Paga No. III-28 Test Report No. 47193-1 REVISION A The time compression form of the Arrhenius equation is given in Appendix I of Section X as:
tA = ts (exP ((Ea/kB ) (1/TA - 1/Ts))) .(1)
Where tA = accelerated aging time (hours) at temperature TA ts = normal service time (hours) at temperature Ts exp = exponent to base e Ea = activation energy (eV) kB = Boltzmann's constant (8.617E-5 eV/0K)
TA = accelerated aging temperature (OK)
TX = normal service temperature (OK)
When multiple normal service temperatures are involved, equation (1) takes the following summation form:
n tA = { t (expi ((Ea/k )(1/TA B - 1/T )))i (2) i=1 Where n = number of different normalservice temperatures ti = normal service time (hours) at temperature Ti Ti = ith normal service temperature (OK) and other variables are as defined above for equation (1).
EXAMP121. Calculate the required aging time at 700C using an activation energy of 1.24 eV to simulate ten years of exposure to the normal service temperatures specified in Paragraph 2.1.1 of Section X. We shall use equation (2) with n = 3 and the following values assigned:
T 1= 200C = 2930K,11 = 43680 hours T 2= 300C = 3030K,12 = 29040 hours T 3= 400C = 3130K,13 = 14880 hours TA = 700C = 3430K WYLE LABORATORIES Huntsville Facility
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Paga No. III-29 i Test Report No. 47193-1 REVISION A l
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Aging time, tA, will be given by:
t A = 43680 exp ((1.24/kB) (1/343 - 1/293)) + 29040 exp ((1.24/kB) (1/343 -1/303))
+ 14880 exp ((1.24/kB ) (1/343 - 1/313) i
%34.0 + 114.3 + 266.9 % 416 hours0.00481 days <br />0.116 hours <br />6.878307e-4 weeks <br />1.58288e-4 months <br /> END OF EXAMPLE 1 Component temperature rise can be factored into equation (2) by adding the tempera-ture rise to each service temperature as follows:
n t
A * { t exp i ((Ea/kB)(1/TA - 1/(Ti + TR))) (3) i=1 Where TR = component temperature rise during normal service (OC), temperature rise is assumed to be constant throughout the range of normal service tempera-tures.
EXAMPLE 2. Calculate the required aging time to simulate the conditions of example 1 for equipment having a temperature rise (TR) of 200C. Using equation (3):
t A = 43680 exp ((1.24/kB)(1/343 - 1/(293 + 20)))
+ 29040 exp ((1.24/kB) (1/343 - 1/(303 + 20)))
+ 14880 exp ((1.24/kB) (1/343 -1/(313 + 20)))
%780.3 + 2161.8 + 4221.4 % 7167 hours0.083 days <br />1.991 hours <br />0.0119 weeks <br />0.00273 months <br /> l l
END OF EXAMPLE 2 l
l Energized equipment is~not, in many applications, energized throughout its service life l and does not, therefore, continuously endure the added thermal degradation resulting from this heat rise. In order to avoid over-conservative thermal aging of a specimen, ,
it is possible to factor the equipment duty cycle into equation (3) to obtain a more realistic thermal aging program. Equation (3) must be modified as follows to factor in equipment duty cycle, d:
I i
WYLE LABORATORIES Huntsville Facility
Paga No.111-30
, Test Report No. 47193-1 REVISION A n
tA=d [ t exp i ((Ea/k )(1/TA B - 1/(Tj + TR)))
i=1 ;
n
+ (1-d) { t expi ((Ea/k )(1/TA B - 1/T i)) (4) i=1 Where d = equipment duty cycle (dimensionless), representing the fraction of service time during which the equipment is energized.
Inspection of equations (2), (3), and (4) reveals that the thermal aging time require-ment for a given duty cycle is a fraction of the energized and de-energized aging times, tAE and tAD; equation (4) can thus be simplified to:
tA=dtAE + (1-d) tan (5)
Where tAE= aging time (hours) to simulate 100 percent operating time (d = 1),
calculated using equation (3) i TAD = aging time (hours) to simulate no operating time (d = 0),
calculated using equation (2)
EXAMPLE 3. Calculate the aging time required for the equipment in Example 2 If it has a 20 percent (d = 0.20) duty cycle.
From Examples 1 and 2, tap = 416 hours0.00481 days <br />0.116 hours <br />6.878307e-4 weeks <br />1.58288e-4 months <br />, tAE = 7167 hours0.083 days <br />1.991 hours <br />0.0119 weeks <br />0.00273 months <br /> -
hence, tA = 0.20 (7167) + 0.80 (416)% 1433.4 + 332.8 m 1767 hours0.0205 days <br />0.491 hours <br />0.00292 weeks <br />6.723435e-4 months <br /> END OF EXAMPLE 3 Further reduction in thermal aging time may be accomplished by increasing the thermal aging temperature. One method of doing this is to energize equipment during thermal aging; equations (2) and (3) become n
t t iexp ((Ea/kB )(1/(TA + TH)- 1/Tg)) (6)
An = i = 1 n
tA t iexp ((Ea/kB )(1/(T A + TH )- 1/(Ti + TR))) (7)
E=i=1 WYLE LABORATORIES Huntsville Facility
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Paga No. III-31 Test Report No. 47193-1 REVISION A where TH = equipment temperature rise (OC) at aging temperature TA and all other variables are as previously defined.
EXAMPLE 4. Determine the required aging time to simulate the conditions in Example 3 if aging is conducted with the equipment energized; assume the tempera-ture rise at the aging temperature is 200C. From equations (6) and (7),
t An= 43680 exp ((1.24/kB )(1/(343 + 20)- 1/293))
+ 29040 exp ((1.24/kB )(1/(343 + 20)- 1/303))
+ 14880 exp ((1.24/kB )(1/(343 + 20)- 1/313))
% 3.37 + 11.32 + 26.45 % 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br /> tAE= 43680 exp ((1.24/kB )(1/(343 + 20)- 1/(293 + 20)))
+ 29040 exp ((1.24/kB )(1/(343 + 20)- 1/(303 + 20)))
% 77.7 + 214.3 + 418.4 x 711 hours0.00823 days <br />0.198 hours <br />0.00118 weeks <br />2.705355e-4 months <br /> Using these values in equation (5) yields an energized thermal aging time of:
tA = 0.20 (711) + 0.80 (42) = 142.2 + 33.6 m 176 hours0.00204 days <br />0.0489 hours <br />2.910053e-4 weeks <br />6.6968e-5 months <br />
, END OF EXAMPLE 4 It is often useful upon completion of thermal aging to determine resultant thermal equivalent life under different sets of normal service conditions. One method of doing this is to convert the normal service conditions into an equivalent time, tEQ, at the aging temperature using whichever of equations (2) through (7) that apply. The results of these calculations are then used as follows, IEQ = (tA/tEQ) Is (8) where IEQ = Thermal equivalent life (years) at the new service conditions resulting from aging time, tA tA = actual thermal aging time (hours) tEQ = thermal aging time required (hours) to simulate life,1s, when subjected to the new service conditions of interest is = desired thermal equivalent life (years) at the new service conditions; this number is selected arbitrarily. Note that the ratio Is/tEQ results in the number of years of equivalent thermal life at the new service conditions per hour of thermal aging at TA*
WYLE LABORATORIES Huntsv611e Facility
Page No. III-32
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Test Report No. 47193-1 REVISION A EXAMPLE 5. A test specimen was aged energized for 711 hours0.00823 days <br />0.198 hours <br />0.00118 weeks <br />2.705355e-4 months <br /> at 700C to simulate a ten-year life at the conditions previously specified with a 100 percent duty cycle and a 200C temperature rise. Determine the thermal equivalent lives resulting from this aging for the same environmental conditions, a 100C temperature rise with a 20 percent duty cycle and a 500C temperature rise with a 50 percent duty cycle.
The energized aging time is given by equation (7) as, 43680 exp ((1.24/kB )(1/(343 + 20)- 1/(293 + 10)))
tAE (100C) =
+ 29040 exp ((1.24/kB) (1/(343 + 20)- 1/(303 + 10)))
+ 14880 ((1.24/kB )(1/(343 + 20)- 1/(313 + 10)))
% 17.1 + 51.6 + 109.8 % 179 hours0.00207 days <br />0.0497 hours <br />2.959656e-4 weeks <br />6.81095e-5 months <br /> 43680 exp ((1.24/kB )(1/(343 + 20)- 1/(293 + 50)))
tAE (500C) =
+ 29040 exp ((1.24/kB )(1/(343 + 20)- 1/(303 + 50)))
+ 14880 ((1.24/kB )(1/(343 + 20)- 1/(313 + 50)))
% 4329.3 + 9446.7 + 14880 % 28656 hours De-energized aging time was calculated in Example 4 and is 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br />.
Combining for duty cycle using equation (5) yields, t Eq (100C) = 0.20 (179) + 0.80 (42) = 35.8 + 33.6 % 70 hours8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br /> tEQ (500C) = 0.50 (28656) + 0.50 (42) = 14328 + 21.0 % 14349 hours The resultant equivalent lives are given by equation (8) and are as follows:
IEQ (100C) = (711/70) 10 % 101.57 years l Eq (500C) = (711/14349) 10 % 0.49 years END OF EXAMPLE 5 l
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