ML20140B978

Forwards Summary of Thermo-Lag Ampacity Derating Methodology in Response to RAI Re GL 92-08, Thermo-Lag 330-1 Fire Barriers

ML20140B978
Person / Time
Site:	Beaver Valley
Issue date:	03/25/1997
From:	Jain S DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-92-08, GL-92-8, TAC-M85517, NUDOCS 9704010555
Download: ML20140B978 (18)

Text

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y VaHey Power Station Shppingport, PA 15077-0004

• March 25, 1997 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 )

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Subject:

Beaver Valley Power Station, Unit No. 2  ;

Docket No. 50-412, License No. NPF-73 '

Response to Request for Information Regarding Ampacity Derating of Cables Enclosed in Thermo-Lag 330-1 Fire Barriers

References:

1. NRC Letter to DLC dated September 28,1995, " Responses to Requests for Additional Information Regarding NRC Generic Letter 92-08, j BVPS Unit 2"(TAC No. M85517)  ;

2. DLC Letter to NRC dated December 1,1995, " Response to Follow-up j Request for Additional Infonnation Regarding Generic Letter 92-08, l

Thenno-Lag 330-1 Fire Barriers." 1 Reporting Requirement Item 2(c) of GL 92-08 requests infonnation concerning the ampacity derating of cables enclosed in Thermo-Lag fire barriers and the evaluation and )

application of test results performed to determine the ampacity derating. Our preliminary response to the Nuclear Regulatory Commission (NRC) dated December 1, 1995 (Reference 2) to the NRC's Request for Additional Information (RAI) dated l' September 28,1995 (Reference 1) was determined to be incomplete by the NRC staff.

The Staff requested via telecon dated March 14,1997, that Beaver Valley Power Station 1 (BVPS) Unit 2 submit ampacity derating evaluations, including any applicable test j L, l

reports. Also requested were the anticipated test procedure or a description of the analytical methodology (including typical calculations) that will be used to detennine the ampacity derating parameters for Thenno-Lag fire barriers installed at BVPS Unit 2. , ,

In response to this request, enclosed as Attachment 1 is a summary of our hf4 methodology and sample BVPS calculations that are being used to conduct engineering evaluations of the BVPS Unit 2 Thenno-Lag fire barriers to determine ampacity derating DEllVERING 9704010555 970325 00 ALITY PDR ADOCK 05000412 [g[ggy qi g gg %%

PDR ,

Be:.ver Valley Power Station, Unit No. 2

,. Response to Request for Infonnation Regarding Ampacity

'Derating of Cables Enclosed in Thermo-Lag 330-1 Fire Barriers Page 2 parameters. Our evaluations include development of an ampacity derating table which lists all cables and raceways being analyzed. No plant specific ampacity derating tests have been performed. Consequently no test reports or anticipated test procedures were developed.

l We project that the ampacity evaluations associated with the Thermo-Lag installations will be completed by September 29,1997. As requested in Generic Letter 92-08, confirmation in writing will be provided upon completion of the actions noted l above. Should you have any questions concerning this matter, please contact Mr. Jay Arias, Director, Safety & Licensing at (412) 393-5210. l Sincerely,  :

i ts' --

Sushil C. Jain l c: Mr. D. M. Kern, Sr. Resident Inspector Mr. H. J. Miller, NRC Region I Administrator Mr. D. S. Brinkman, Sr. Project Manager

Pagn 1 of 16.

ATTACHMENT 1 j '

Summary of'Ihermo-Lag Ampacity Derating Methodology for BVPS Unit 2 l

] OBJECTIVE I 'lhe purpose of this calculation is to evaluate the electrical cable ampacity for the Thermo-lag fire 2

wrapped conduits at BVPS Unit 2. The Texas Utilities Electric Company (TUEC) Comanche Peak SER dated June 14,1995 identified NRC corrected values for the allowable derating factor of 21% for one hour I conduit configurations. A review of the conduit installations utilizing Thermo-lag fire wrap at BVPS Unit 2 j was performed to determine the available ampacity margins. In all cases as shown on the attached "Thermo-

) lag derating data table," the available margin is greater than 21%. l

!. The conduit configurations tested by TUEC are similar to the configurations at BVPS Unit 2. The  !

BVPS evaluation will use these configurations, and other industry experience, to refme a heat transfer model l

l of similar configurations at BVPS such that the results will closely match the tested configurations. All

! conduit configurations will then be analyzed to evaluate BVPS configurations taking into account i

appropriate factors derived from the heat transfer model. Exceptions will be justified usi % urther f analysis 1

in conjunction with test data.

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l Certain conduit configurations at BVPS differ from the TUEC test cases due to factors such as number and type of cables in the conduits, and the conduit material and size. The derating factors in the analysis will utilize test information to validate the heat transfer models for these configurations to the

. greatest extent possible. If test information is not available, analytical methods will be used for cable

[ derating.

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Pags 2 of 16.

METHODOLOGY This analysis calculates the conductor temperature of the cable inside the conduit. The initial method of heat transfer is a one directional heat flow method if the analysis indicates an excessively high conductor ampacity derating, additional analysis or other considerations may be required. All of the cases with more than one cable in the conduit will be calculated using a bi-directional heat flow method.

The heat transfer mathematical model will be compared with Comanche Peak's (TUEC) test for validation. Other appropriate industry tests will be used if necessary. In the mathematical model validation process, test specimens will be used to refme mathematical model parameter values used in the analysis.

The heat transfer method is utilized by the mechanical engineering industry for calculating heat losses from insulated pipes. (The Neher and McGrath method (N-M) also uses the similar theory). The heat

~ transfer approach calculates maximum conductor operating temperature by taking into account the maximum required ampacity of the cable in a conduit with one cable. For conduit with more than one cable, the largest current carrying cable will be multiplied by 1.25 and full load currents for the remaining cables will be used to determine the heat developed by the cables in the wrapped conduits. The N-M method was originally utilized for Beaver Valley Unit 2 in the calculation for multi-cabled conduits.

Although the N-M calculations included the Thermo-lag wrapped cables, the original N-M calculation only determined the derating factors for all power conduits provided with the multi-cabled arrangement. Where such conduits were provided with TSI fire wrap, the calculated currents were then further derated using the originally published TSI derating factors.

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Peg 3 3 of 16.

APPLICATION OF METHODOLOGY I As stated this calculation will be utilizing the heat transfer method. This application of methodology will include the thermal characteristics of Thermo-lag material, air, cable material and conduit material in calculating the cable conductor temperature for the derating impact. The heat transfer method used for this calculation is described as follows. The method is based upon the following formula:

W=1R, 2 a Watts per foot @ l Where I = The maximum required cable ampacity.

Rac = The AC electrical resistance of an individual conductor responsible for heat generated l

within the conductor due to electric current flow (Ohms per ft).

W = Heat released by the loaded conductor.

I= ne maximum load current of a conductor, q, = n'xW x 3.415 BTU / Hour @

l l

y, = Eq, Total heat released by all the cables in the conduit (BTU / Hr) @

Where y, = Heat released by cable in BTU / Hour.

n' = Number ofloaded conductors of a cable.

I D'ox In(b)

D D, x in D, x in #

2 l '

+ < Du + <Da> +

2Kat 2Kai, 2Kui hs am l l

Where Uo = Over all heat transfer coeflicient for outside area.

D 2= Conduit inside diameter.

D3= Conduit outside diameter D= 4 Inside diameter of the TSI wrap (effect of the air gap thickness between conduit and TSI). I D, = Overall diameter of the TSI wrap. (Note that this is being upgraded and will impact the analysis)

Kof = Thermal conductivity of the aluminum in BTU / hr- fl - deg F t K,j, = Thermal conductivity of the air in BTU / hr - ft - deg F Kui = Thermal conductivity of the TSI material in BTU / hr - fl - deg F hamb = heat transfer coeflicient in BTU / hr - fl - deg F.

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l Pegs 4 of 16.

D', = equivalent diameter (equivalent diameter of the cable contact surface area with inside

' surface of the conduit).

D', = 4 x A P @

A=

Where Cable unit surface area touching the conduit i

P= Perimeter of the contact area.

The above heat transfer philosophy is used in partially filled insulated pipes. The wetted perimeter with respect to hydraulic parameter is compared with the cable area touching the conduit surface. The effective diameter of the 3-1/c cable or for the conduit with more than one cable is calculated by the formula used in the analysis E-134 (ref.1). De formula for the equivalent diameter for group of cables is as follows:

D,, = (ID,,,) - ' (D,i)- 2 (gc ,) _ _ _ n (pc,,) g Where D,8 =

equivalent diameter for group of cables.

D,,, = diameter of the individual cable.

/_D c,, = angle in degrees for a cable when all the cables are geometrically plotted and center lines are connected for group of cables.

Once the heat transfer coefficient is calculated, the cable surface temperature can be calculated using following foimula:

laInF = lambF + O Uox 2TI x go xL 2

Where lainF = temperature of the n* cable outerjacket.

tambF = Ambient air temperature in the area L= Conduit unit length (1 ft).

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l Pcg3 5 of 16.

Once the cable outerjacket temperature is calculated, the conductor temperature can be calculated osing the following formula.

In #'"'" In /""

qn < Rc,, > < Ri ,,,,, , I t,,,s,p = + + +tcblF @

H,nx2fI h,in, K,p R,&m x h,,i,.

Where tcaedrF = the conductor temperature in deg F for nth cable in the conduit.

Rj,,,,, =

insulation radius of the n* cable.

Rm =

Conductor radius of the n* cable.

I Rm p Jacket radius of the n* cable. '

Kjn, =

thermal conductivity of the cable insulating material.

1 K,=

p thermal conductivity of the cablejacket material.

h,,f,. =

thermal coefficient of the surface air film at the cable.

J The conductor temperature calculated above is in deg F units. To obtain the result in percentage derating factor, the conductor temperature should be converted into deg C units. By using the following i equation the allowable current at 90 deg is calculated:

(234.5 + 90) amps @

I,,90c = (234.5 + t,,,,,r)ischtx l Where I, 90C = Conductor temperature of the n* cable at 90 deg C. l t,,,,,g -

= Calculated corductor temperature at maximum required ampacity.

1,,cbf = Maximum required ampacity of the n* cable (used in the analysis). l The ratio of the maximum available ampacity using the Thermo-lag der ~ating factor and ampacity of the cable in the conduit is then subtracted from one to calculate the derating factor of the cable. For more than one cable in the conduit, the maximum derating factor shall be used for further derating evaluation of cables for conduit grouping factors.

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REFERENCES l)

• Okonite Bulletin ElfB-90, Engineering Data for Copper and Aluminum Conductor Electrical j

- Cables.

2) Beaver Valley Unit 2, Project Specification,2BVS-312, insulated Power Cables - 600 VAC.

3) Beaver Valley Unit 2, Project Specification,2BVS-309, Insulated Power Cables - 5000 VAC.

4) ANSI C80.1-1982 American National Standard for Rigid Metal Conduit.  !

, 5) IPCEA P-46-426, Index of Power Cable Ampacities for Aluminum, and Copper Conductors. f

6) lleat Transfer, Pitts & Sissom, Schaums Outline Series, ; McGraw-lioll 1977, i

7) Thermal Science,INC Technical Note 92883A. Sept 1983.

8) NRC Generic Letter 92-08, dated 12-17-1992, TliERMO-LAG 330-1 FIRE BARRIERS.

9) Beaver Valley Unit 2, Project Calculation 10080-E-201 Rev.1-A2, DC System Management  !

BAT *2-1/ BAT *CliG2-1. i

10) Beaver Valley Unit 2, Project Calculation 10080-E-68 Rev. 4, Station Service Voltage and Load f

Analysis. I II) Beaver Valley Unit 1, Project Calculation 8700-E-261 Rev. O, DLC Qualification of Cable Sizing Calculation Program. l t

12) Engineering licat Transfer, B. V. Karlekar and R. M. Desmond.

13) Flow of Fluids, By CRANE Company, Technical Paper No. 410.

14) TUEC test report, "Ampacity Derating of Fire Protected Cables" dated March 19,1993.

15) TUEC SER, dated June 14,1995. I i

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Prga 7 of 16.

DESIGN INPUTS Input parameter list i

e Cable ampacities, refer to 9 and 10 of Reference list.

Cable dimensions, Reference to 2,3, and 4 of Reference list.

. Cable impedances, refer to 11 of Reference oflist.

Thermal goperties of air and aluminum refer to 6 of Reference list.

e The, mal properties of TSI Thenno-lag, refer to 7 of Reference list.

i e Dimensions of conduits, refer to 4 of Reference list.

• TUEC test report, refer to 14 of Reference list.

1 ASSUMPTIONS A. The air gap between conduit outer surface and Thermo-lag fire wrap inner surface is assumed to be 0.1 inch. This assumption is based on evaluation of photographs and field walk downs 1

performed by engineering personnel. This assumption is conservative because the assumption of an air gap reduces the heat transfer from the conduit to Thermo-lag fire wrap.

B. Intermittent load such as process heating load do not increase the conductor temperature of the of cables in the same raceway to the maximum limit. When the load starts, the temperature of the surrounding cables will increase slightly, but when the load dc<nergizes, the cables along with the heater load cables stan cooling.

ACCEPTANCE CRITERI A The Thenno-lag fire wrapped Cable ampacities are considered adequate if the adjusted cable ampacities, calculated cable ampacities after applying the conduit grouping factor exceed the load current aquirements for the cables.

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P gs 8 of 16.

Sample Validation of Thermo-laa fire wrapped cable in the heat transfer method.

The validation analysis is performed based on the TUEC test for a 5 inch conduit using a 750 MCM single conductor 600V cable. TUEC used 88 feet of cable for testing with 4 passes through the conduit. The TUEC result shows that at 89.4 deg. C, the conductor current was 564 amps.

The validation analysis is done with 2 -2/C 600 V DLC mark No. NKZ-30 cab!e. The calculated ampacity of 513 amps is conservative for the approach.

The changes in the sample analysis are the replacement of steel conduit with aluminum conduit and actual cable data for the cables in the conduit. This validation analysis considers one directional heat transfer from cable to conduit. The heat dissipation through air is not considered at this point. However, the additionalimpact of heat loss from all the directions will be added to more closely match the tested ampacity. P l

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Pega 9 of 16 Samole Validation of a Thermo-laa wracoed 2 2/C cable in a conduit usina Heat Transfer method Co'nduit 5 in test conduit with 2 2/C 750 MCM cables D oconduit ::5.583 Conduit outside Dia.

U iconduit := 5.047 Conduit inside dia.

Cable 750 MCM 2 2/C test cable (information for DLC mark No. NKZ-30 600 volt data is used) '

Dcbl := 2.566 Cable Dia. Ireqd := 567 Amps required (TUEC tested amps)

R c99c ::0.023310'3 Conductor AC resist. n' := 4 Total conductors in the conduit Losses in watts per foot / conductor W :: Rac99c 1reqd W = 7.49 Watts q := W 3.415 q = 25.58 BTU / Hr.

per conductor q g := n%q q g = 102.32 BTU / Hr. heat released in the conduit

._l.1 BTU / Hr.-ft-deg F .I tai 'I2' Thermal conduc%

t tsi = 0.02 Thermo-lag material of Themo-lag t tsi .: --

12 thickness in feet U1 12 U 1 = 0.21 ft. Cable Diameter D 2 :: D 2 = 0.42 ft. Conduitinside Diameter 12 i

D 3 :: D 3 = 0.47 ft. Conduit Outside Diameter 12 L

t airgap := t airgap =0.0083 ft. Air gap thickness between conduit and Thermo-lag D 4 ::D3+2t airgap D 4 = 0.48 ft.Thermo-lag inside diameter D 0 :: D4+2t ts ft. Thermo-lag outside diameter l'sa r := 1.65 BTU / hr-sq.ft-deg F (Film coefficient for a still air inside conduit and between thermo-lag and coupling) t mnbF := 104 Deg F ambient air temperature hamb := 1.65 BTU / hr - sq.ft - deg F (Ambient air film coefficient)

Kair : 0.014 BTU / hr - ft - degF (Thermal conductivity of the air)

K stl := 26.5 BTU / hr - ft - degF (Thermal conductivity of the steel)

Piga 10 of 16 Samole Validation of a Thermo-laa wrapped 2 2/C cable in a conduit usina Heat Transfer method j $:=25 deg. Surface contac' angle between equivelent cable diameter and inside conduit.

$ rad I'---- t rad = 0.44 angle in radians L :: 1 Unit conduit length 180  !

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! Dg A := ( rad L A = 0.047 Cable unit surface area touching the conduit 2 l I DI 2 l

)- P := + 2.L P = 2.18 Conduit unit surface perimeter touching cable i 2 Irad 2 )

J 4A D' O = 0.09 Cable equivelent diameter D'O :: P I

1 U 0~

(D 3 (D 4' (D 01 0 = 0.66613 J D'oIn D o.in D D0"I D  !

(D 2/+ - 4 3j + ( 4j + i Heat transfer coefficent 1 2.K stl 2K ar 2K ts h amb i

9t tcblF := t ambF + 1cblF = 197.38 deg F. Cable Jacket temperature D

U 02.n 0L 2

test cable (NKZ-30,2-2/C cable) l Dc := 0.998 Conductor dia, n .: 4 No. of conductors.  !

1 t ;j :: 0.080 + 0.000 Ins. Thickness t c; ::0.0065 Outer Jacket Thickness Kins : 0.087 Kjkt ::0.087 Thermal conductivity of the cable material  ;

De Conductor t Conductor + 1j o

R e

g,- radius R ins ::Re + ij Rjet ::R ins + 3 4

Radius of single conductor (R ins i (Rjet I

with Jacket.

In in 9t R tcondlF 4 ej+ (Rins/

+

1 n, 2 n K, ins

+tcblF 4

k,jkt Rjet hsair.

^

l L 1 t condlF = 255.44 deg. F, Conductor temperature at required load t deg. F. Conductor temperature at condC ':(t candlF- 9 32) 5 tcondC = 124.13 required load

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j Conductor ampacity at 90 deg C \

t

)

234'5 + 90 l reqd I Ic90 = 513.04 Amps Maximum allowable cable

1 c99 '

234.5condC +t ampacity ,

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1 SAMPLE ANALYSIS Pagn 11 of 16 Evaluation

~ of a Thermo-laa wracoed 3/C cable in a conduit usino Heat Transfer method The sample analysis is performed using one cable in the conduit.The result shows that j

162 amps can be drawn without exceeding 90 deg. C. Maximum required ampacity for '

this load is 146.3 amps. Therefore, the ampacity is acceptable for the cable in this conduit.

Using 21% TUEC requirement the cable can be loaded up to 221 (280

• 0.79) amps.

Conduit 2CH9570B (CAC-11)

D oconduit := 5.583 Conduit outside Dia.

D iconduit := 5.047 Conduitinside dia.

Cable 2SWSAOH301 (NKB-05) n' := 3 D cbl := 2 65 Cable Dia. Ireqd := 146.3 Amps R ac90c := 0.0688 10'3 Conductor AC resist.

l Losses in watts per foot / conductor W := Rac90c'Ireqd W =1.47 Watts q := W 3.415 q = 5.03 BTU / Hr.

q g := n' q q g = 15.09 BTU / Hr. 5I ,

8 tsi := t tsi = 0.06 Thermo-lag thickness BTU / Hr.-ft-deg F 12 Ktsi .= in feet 12 D chl D g :: D 3 = 0.22 ft. Cable Diameter 12 D iconduit D2 D 3* = 0.42 ft. Conduitinside Diameter 12 D 3 := D 3 = 0.47 ft. Conduit Outside Diameter 12 I.

t airgap := t airgap =0.0083 ft. Air gap thickness between conduit and Thermo-lag I

D 4::D3+2t airgap D4 = 0.48 ft. Thermo-lag inside diameter D0::D4+2t tsi ft.Thermo-lag outside diameter K tsi  :=12N BTU / hr - ft - degF Thermal conductivity of the Thermo-lag BTU / hr-sq.ft-deg F (Film coefficient for still air inside hsair = 1.65 conduit,between Thermo-lag and conduit and outside Thermo-lag l material)

Deg F ambient air temperature  !

t ambF := 104 1 hamb := 1.65 BTU / hr - sq.ft - deg F (Ambient air film coefficient)

K air := 0.014 BTU / hr - ft - degF (Thermal conductivity of the air) l

l Pags 12 of 16 SAMPLE ANALYSIS

]

[ . Evaluition of a Thermo-laa wrapoed 3/C cable in a conduit usina Heat Transfer method K .3 := 117 BTU /hr-ft-degF (Thermalconductivityof the Aluminum)

$ := 32 dog (Surface contact angle between cable and conduit) i

" t I rad = 0.56 Angle in radian L := 1 Unit cable length (rad.*t'180 Dg i L A = 0.062 Cable unit surface area touching the conduit A := $ rag 2 1

q P ,=

( p2 Cable perimeter 4,

+2L P = 2.23 for contact area t 2.$ rag 2 / D' O . = - '

D' O = 0.11 P

Cable equivelent diameter  !

e -

I U0 ~-

(D 3) (D 41 IDOI 0=0 m  !

D'0in D 0'ID -

U O 'I D Heat transfer coefficient 4 (U2/ + - ( 3/ + i 4/ + 1 2 K ,i 2Kair 2.Kg3; h amb 9t t cblF ' ambF + IcblF = 120.87 deg F. Cable Jacket temperature D

U02 n --0L

2  !

4 Cable 2SWSAOH301 (NKB-05,3/C cable) j De := 0.528 Conductor dia, n := 3 No. of conductors.

t ;j := 0.125 + 0.095 Ins. Thickness t oj :=0.125 Outer Jacket Thickness K ins := 0.087 Kjkt '= 0.087 D Conductor t .. ft. insulation R 1-radius ft. R ins := cR + 3 radius 1

c := 212 12 Rjet .= R ins + 12 1

' Conductor radius with Jacket.

l IR ins i fRjet in in R

icondlF 91 (Rej+ 1 nst +

I j n, 2 s K jkt +t cblF K ins Rjet hsa r, 4

tcondlF = 138.12 deg. F, Conductor temperature at required load i

t

"- condC (I condlF-9 32).5 t condC = 58.% deg. F, Conductor temperature at required load Conductor ampacity at 90 deg C a

234.5 + 90 1 'I reqd I 1c90 = 161.78 Amps 1c90 234.5 + tcondC i

_ _ . _ _ - _ _ _. __ _ _ _ . _ . _ _ _ _ _ _ _ _ .._ . . _ . _ . _ _m_.,

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. Simpb cn: lysis 2 ( 4 cables in a c:ndult) Paga 13 of 16 r Evaluation of four cables in a Thermo lan wrannad conduit usina Heat Transfer method

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', *Qonduit 2CL6070D (CAC-11) one hour fire wrap 5.583 Docond ; Conduit Outside Dicond := ' Conduitinside dia. in ft 12 12 Diameterin ft l Cables in the conduit '

2BYS10L604,28YS10L605,28YS10L606 (NKA-74 QUAD cable) . n' j:=12 conductors  !

1 R ,c99cg := 0.346510'8 Ohms / Foot I f reqd := 19.1 Maximum required ampacity 2EHSAOL205 (NKZ-2L Triplex Cable) n' 2 := 3 No. conductors

R ac90c2

= 0.0593 10-' Ohms / Foot i2reqd := 46.0 Maximum required ampacity i

l l Losses watts / ft per conductor W ic := Rac90c1'I Ircqd W j e = 0.126 q je := W ic 3.413 q je = 0.431 BTU /Hr W2c:=R ac90c2'I2reqd W2c = 0.125 q 2c := W2c'3 413 9 2e = 0.428 BTU /Hr

! q g := n' g*q ge q g = 5.177 BTU /Hr. 9 2 := n' 2'9 2c 9 2 = 1.285 BTU / Hr.

! qt 91 + 92 9 t = 6.462 BTU /Hr (Total heat from all the cables) -

1,3 f1 5 1 K BTU / Hr - ft-deg F 1

+-

t t i := 12 Thermo-lag i tsi I tsi = 0.063 ft. Thickness of I thermal condu% ' '12 Thermo-lag material D g := 4.06 ft. equivelent cable diameter in a conduit.

12 D 2::D icond Conduitinside diameterin ft.

D 3 .= Docond Conduit outside diameter in ft.  ;

l_1) t airgap I airgap = 0.0083 ft. Air gap thickness between conduit &

\ 2) Thermo-lag l D 4 ::D3+2t airgap D 4 = 0.482 Inside dia. of Thermo-lag in ft.

Do :: D4+2ttsi D o= 0.607 ft. Outside diameter of Thermo-lag material hamb := 1.65 Thermal coefficient of the air film at the surface.

K 3;:= 117 Thermal conductivity of the aluminum conduit.

Ka r := 0.014 Thermal conductivity of the ambient air.

t ambF := 104 Deg F, normal ambient temperature of air in service building. .

l C:nduit 2CL6070D (CAC-11) ene h:ur fire wr:p Page 14 of 16

. ( :: 54 deg (The angle measured for surface contact area of cable to inside conduit diameter).

$ rad 0 t rad = 0.942 The angle converted in radians.

180 L := 1 length of the conduit for unit length analysis, D2 A : (rad. -L A = 0.199 area cable surface contact using unit cable and 2

conduit length.

I D\2 P := +2L P = 2.398 Permeter of the area in contact between cable i 2 4 rad 2 )

and conduit.

D'o:= D'o = 0.332 Effective diameter of the cable used for heat transfer analysis I

U ::

(D 31 (D 41 (DoI D' d tn -

D dn i D  !

(D2 )+ -3j (D + d"D;+; 4 g 2K i 2Kair 2K tsi h amb U o= 0.469 Heat transfer coefficient for unit area.

9t tcblF .: t ambF +

Do tcblF = 111.227 Deg F, temperature of i U g2 n L the cable surface.

2BYS10L604,28YS10L605,2BYS10L606 (NKA-74, Quad Cable)

Kins := 0.087 K jg.t ::0.087 Thermal conductivity for the cable material.

Dc g := 0.232 in. Conductor Dia. t j g := 0.080 in. Outer Jacket Thickness t ;g .= 0.055 a NO Iro,. Thickness D ,;g :: 1.170 Cable Diameter U ci t R insi :=R ; + il ci := 212- Conductor radius in ft. R c 12 R insi =0.014 Insulation radius in ft.

Rjeti <=R insi + RJct! =0.021 Jacket radius in ft. hsa r :: 1.65 Thermal coefficient of air fR inst g g lRjet]

I condlF 91 i R;j+

c gR insl)

+

1

+tcblF n, j 2 n k, ins k. jkt Rjet1 hsair tcondlF = 113.826 Deg F conductortemperature t Deg C conductor temperature condlC9(tcondlF - 32) t condlC = 45.46

Conduit 2CL6070D (CAC-11) ene h ur fire wr:p ags 15 of 16

'+9

~ treqd I Ic90 = 22.14 Ampacity required at 90 deg C

} Ic90 : (234 5 + t cond1C)I 1

i 2EHSAOL205 (NKZ-27 TRIPLEX cable) '

Dc2 := 0.575 in. Conductor Dia. D si2 := 1.903 in. Cable Diameter t ;2 := 0.065 + 0.065 Ins. Thickness t j2 := 0.000 Outer Jacket Thickness D c2 R -

R c2 = 0.024 ft, c,nductor radius I c2 := 212 )

t ;2 ft, insulation radius R ins 2 := R c2 +Rins2 12 = 0.035 RJct2 := R ns2 + Rjet2 =0.035 ft. Jacket radius (no Jacket for this cable)

(R ins 2) g IRjet2 92 R i

c2)+ (R ins 2) I t cond2F +

+IchlF

"* 2 2 n Kins b,jkt Rjet2.huir tcond2F = 112.71 deg. F, Conductor temperature I

cond2C (I condlF- 32). tcond2C = 45.46 deg. C, conductor temperature.

I +

2reqd I2c90 = 53.32 Maximum ampacity required at 2c90 (234.5 + t cond2C)'l 90 deg C.

Duquesne Light Co. Thermo-lag derr. ting d;t3 table 3/19/97 .

CONDUIT Desbnabon .

Avsamble RACEWAY Mark No Di Do Cable Mark No. O See Type From To One cabne Rahng Dia 90 C g Ampac#y before

• '*inD 2CH9490B1 CAC-10 1 4 00 4 050 4 500 2SWSAOH301 NKB-05 0 0688 40 3 4KVS*2AE 2SWS*P21 A 280 146.3 47.8 %

2CH9570B CAC-11 1 5 00 5 073 5.583 2SWSAOH301 NKB-05 0 0688 4/0 3 4KVS*2AE 2SWS*P21 A 280 146.3 47.8 %

2CH957PA CAC-11 1 5 00 5 073 5 583 2SWSBPH301 NKB-07 0.1094 2/0 3 4KVS*2DF 2SWS*P21B 212 146.3 31.0 %

2Cl213ND CAC-11 3 5 00 5 073 5.583 2LAPNNLO10 NKZ-01 0.2182 2 D; MCC-2-23 LTG-TRF2-E05 130 32 9 74 7 %

2SCANNLO16 NKZ-01 0 2182 2 DUP MCC-2-23 TRF-PWR2-16 130 54 6 580 %

2SCANNLO17 NKZ-01 0 2182 2 DUP MCC-2-26 TRF-PWR2-17 130 54 6 58.0 %

2SCANNLO25 NKZ-12 0.5508 6 DUP MCC-2-23 TRF-PWR2-20 75 54 6 27.2 %

2SCANNLO26 NKZ-12 0 5508 6 DUP MCC-2-23 TRF-PWR2-21 75 54 6 27.2 %

2CL3010A1 CAC-06 1 2.00 2.083 2.375 2HVZAOL200 NKZ-21 0 2182 2 TRI 480VUS*2-8 2HVZ'FN262A 130 92 6 28 8 %

2CL3010A2 CAC-06 1 2 00 2.003 2 375 2HVZAOL200 NKZ-21 0 2182 2 TRI 480VUS*2-8 .~ HVZ*FN262A 130 92.6 28.8 %

2CL3010A3 CAC-06 1 2 00 2.083 2.375 2HVZAOL205 NKZ-23 0.1376 1/0 TRI 480VUS*2-8 zHVZ*FN261 A 179 113.1 36 8 %

2CL3010A4 CAC-06 1 2.00 2.083 2.375 2HVZAOL205 NKZ-23 0.1376 1/0 TRI 480VUS*24 2HVZ'FN261 A 179 113.1 36.8 %

2CL6050A CAB-08 1 3 00 3 090 3 500 2EHSAOL211 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E07 317 111.0 65 0 %

2CL6070A CAC-08 1 3 00 3 090 3.500 2EHSAOL240 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E01 317 80 97.5 %

2CL6070A1 CAC-08 1 3 00 3 090 3 500 2EHSAOL246 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77.9 %

2CL6070B CAC-08 1 3 00 3 090 3.500 2EHSAOL240 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E01 3$7 80 97.5 %

2CL607OC CAC-12 1 6 00 6.093 6 625 2EHSAOL245 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77 9 %

2CL60700 CAC-11 1 5 00 5.073 5.583 2BYS10L604 NKA-74 0 3465 4 3 DC*SWBD2-1 PNL*DC2-11 91 19.1 79.1 %

28YS10L605 NKA-74 0.34S5 4 3 DC*SWBD2-1 PNL*DC2-11 91 19.1 79.1 %

28YS10L606 NKA-74 0 3465 4 3 DC*SWBD2-1 PNL*DC2-15 91 64 930 %

2EHSAOL205 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E05 317 46 0 85.5 %

2CL6070E CAC-12 1 6 00 6 093 6 625 2EHSAOL245 NKZ-27 0.0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77.9 %

2HVSAOL200 NKZ-28 0 0434 350 TRI 480VUS*2-8 2HVS*FN204A 384 200 0 27.1 %

2HVSAOL210 NKZ-29 0.0316 500 TRI 480VUS*2-8 2HVS*PNLCH219A 477 2770 41 9 %

2CL6070F CAC-12 1 6.00 6 093 6 625 2BYS10L604 NKA-74 0 3465 4 3 DC*SWBD2-1 PNL*DC2-11 91 19.1 79.1 %

28YS10L605 NKA-74 0.3465 4 3 DC*SWBD2-1 PNL*DC2-11 91 19.1 79 1 %

28YS10L606 NKA-74 0 3465 4 3 DC*SWBD2-1 PNL*DC2-15 91 64 930 %

2EHSAOL205 NKZ-27 0.0593 250 TRI 480VUS*2-8 MCC*2-E05 317 46 0 855 %

2EHSAOL246 NKZ-27 0.0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77.9 %

2EHSAOL250 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E15 317 9.0 97.2 %

2CL950BA CAC-11 1 5 00 5 073 5 583 2VBS3BL501 NKZ-05 0 0316 500 QUAD UPS*VITBS2-3 PNL*VITBS2-3A 477 30 0 93.7 %

2CL950RA CAC-12 1 6 00 6.093 6 625 2VBS1RL501 NKZ-05 0 0316 500 QUAD 2JB'8856 2JB*2590 477 5.7 98.8 %

2CL95708 CAC-11 1 5 00 5 073 5.583 2EHSAOL240 NKZ-27 0.0593 250 TRI 480VUS*2-8 MCC*2-E01 317 80 97.5 %

2CL957PA CAC-11 1 5 00 5 073 5.583 2EHSBPL215 NKZ-27 0.0593 250 TRI 480VUS*2-9 MCC*2-E02 317 80 97.5 %

2CH925GC2 CAB-10 3 4 00 4 050 4.500 2CHSCGH301 NKB-31 0.1376 1/0 TRI 2CHS*TRS-P21C 2CHS*P21C 188 90 0 52.1 %

2CL923OA CAC-11 3 5 00 5.073 5.583 2EHSAOL245 NKZ-27 0.0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77.9 %

2FNCAOLOO1 NKZ-21 0 2182 2 TRI MCC*2-E03 2FNC*P21 A 130 40 6 68 8 %

2CL923OH CAC-08 3 3 00 3 090 3.500 2EHSAOL246 NKZ-27 0 0593 250 TRI 480VUS*2-8 MCC*2-E03 317 70 0 77.9 %

2CL957WA CAC-11 3 5 00 5 073 5 583 2VBS2WL501 NKZ-05 0 0316 500 QUAD 2JB 8857 PNL*VITBS2-2A 477 45 5 90.5 %

2DH925G02 3 4 00 4 050 4 500 2CHSCGH301 NKB-31 0.1376 1/0 TRI 2CHS*TRS-P21C 2CHS*P21C 188 90 0 52.1 %

2DH92SOO1 3 4 00 4 050 4 500 2CHSAOH301 N KB-09 01376 1/0 3 4KVS*2AE 2CHS*P21 A 186 90 0 51.6 %

Page 16 of 16 2E138R3.XLS

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