power calcualtions 2014

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FIRE STATION (CD)Contract No.Job No.

Doc No.Calculations by:Checked by: Licence No. 52Design Load Calculation For:Date:

Member Ref.CalculationsPOWER CALCULATION REPORT -IFCRev. 0

TABLE OF CONTENTS

ItemTitle

1.0Scope

2.0Applicable Codes, Standards and References

3.0Purpose

4.0Design Criteria

5.0Calculations

6.0Attachments

1.0Scope:

1.1Generalmanual, standards in conjuction with SEC-ERB design/engineering guide lines and specifications.

2.0Applicable Codes, Standards and References:

NEC-National Electrical Code, 2008SASO-Saudi Arabian Standards Organization SEC-Saudi Consolidated Electric Company

3.0Purpose:

3.1To Determine the -Ratings of unit substation transformers-Secondary OCPD,s-Secondary feeders

3.2To Determine the Size of Branch OCPD and their Feeders HVAC equipments, panel boards, Main switch boards and distribution panels.

4.0Design Criteria for Power Distribution at LV System:

4.1Wires and Cables Specs: The sizes of cables have been selected based on the following:4.1.1Continuous current during normal operation

4.1.2Voltage drop within permissible limits during normal operation as well asstarting condition

4.1.3Cable Catalogue:-Saudi Cables

4.1.4Ambient Temperatures for Cables-In Air 50 deg. C-Soil Temperature (direct buried)40 deg. C-Indoor Air-Conditioned30 deg. C

4.1.5Type of Cables:-Low voltage wires and cable (600 V and below) for major feeders installed inunderground ducts and for indoor installation in raceways, conduits andwireways shall, in general, be 90C rated, cross-linked polyethylene. Buildingwires used for branch circuits up to 100 A can be PVC insulated.

-Low voltage wires and cables for direct burial shall be armored 75C rated,cross-linked polyethylene or PVC insulated and PVC jacketed.

-High voltage cables (above 600 V) shall be 90C rated, be EPR or XLPEinsulated and have metallic shield. Cables used for direct burial purposes shallhave an outer jacket.

4.1.6Maximum permissible volt-drop-5%

4.1.7100% Load Factor

4.4Design Assumptions

4.3.1Overall Efficiency ( h )=0.9

4.3.2Overall Power Factor (p.f)=0.8

4.4Formulaes:4.4.1Input kVA=Total Load (kW) x Overall Diversity FactorEfficiency X Power Factor

4.4.2Voltage Drop Calculations:Applicable only for longer cable runs that causes voltagedrop for more than 3%. Any cables exceeding the limit ischanged to next larger size.

VR=3x L x Ix(R cos + X sin)(N x 1000)Where VR-Total Voltage drop in cable/s

cos -Power factor of load

sin -Reactive factor of load

L-Route Length of Cable (meters)

N-Number of runs of cables per phase

I-Full Load Current (Amps)

R-AC Resistance of Selected Cable at 90 deg C (Ohm/kM)

X-Reactance of Selected Cable (Ohm/kM)

%VD- VRx100V

5.0Transformer Calculations

5.1 Sizing of Transformer

Load DescriptionConnected Load (VA)Demand Factor (%)Demand Load (VA)

1-MDP-FS-CD238906221741Spare - 20%4778144348

Total (VA)286687266089Say (kVA)286.69266.09

Demand Load Current (IDL): IDL =Estimated Demand Load1.732x380=2660891.732 x 380=404.2926461651Amps.

-Transformer Selection:From estimated demand load, apply transformer up-rating factor,Xfmr. kVA=266.09kVA+15% up-rating=266.089248kVA+266.09(0.15)=306.0026352kVA - minimum transformer size

-Select:500 KVA Radial feed Transformer, Pad Mounted33 kV - Delta Primary 380/220V Wye Secondary, 3PH, 60Hz

-Transformer Primary Current:(Ip)=50033x 1.732IP =8.7479879628AMPS

-Maximum Primary OverCurrent Protection: (ICB)ICB =8.7479879628x300%NEC Table 450.3AICB =26.2439638883AMPSSelect :100 Amps Circuit BreakerPrimary Feeder :I =Full load Current x 125%I =10.9349849535Amps

-Provide,3-1/C 95 mm2 CU/XLPE/PVC, 33 kV unarmored Cable

-Maximum Secondary OverCurrent Protection :(ISCB)ISCB =KVAx 10001.732x EISCB =500x10001.732x380ISCB =759.6936915036Amps.

Select,800A, Air Circuit Breaker, 3P , 1000 VAC

-SelectCopper bus bar with a minimum rating of 800 A on the transformer secondary side

-Fault level calculation

Isc =kVA1.732xVxZ%

=500=18.9923422876kA1.732x380x4%

For breaker at secondary side of transformer fault level shall be25kA

5.2Generator # 1 Calculations

Sizing of Generator #1

-DESIGN CONSIDERATIONS1- The power factor is assumed to be 0.852- 20% future load is considered.3- The generator auxiliary power requirement is 5% (Assumed)4- Temperature correction factor is taken as 5% (Assumed)

-GENERATOR DATA1- Short time overload coefficient of a generator, KG = 1.52- Generator power factor PF = 0.83- Permissible transient voltage drop of system Vd at 400V switchboard bus = 2%4- Transient reactance of generator X'd = 10% (Assumed Value, Vendor will Confirm)

-SIZING CALCULATIONS Capacity of Generator is calculated using the following formulae:Capacity Under Normal Running Condition including 20% future spare capacity.

PG1 = 1.20 X TPPL

Where TPPL = Total Plant Peak Load as per Consumer ListTPPL =238.90604kVA(MDP-FS-CD Refer Sheet 07)

PG1 = 1.20 x238.90604kVAPG1 = 286.687248kVA

Temperature correction factor is including 5% under normal running condition.

PG1 = 286.687248x1.05PG1 = 301.0216104

-CONCLUSION 1- The minimum required capacity of Diesel Generator Set is 301.0216104kVAas per PG1 calculation.

2- The Diesel Generator rating has been selected as 500 kVA which is the next size available.

5.3MAIN DISTRIBUTION PANEL (MDP-FS-CD) (EXCLUDING SPARES)


1-PLP-FS-CD30983271182-LP-FS-CD24786247863-PP-FS-CD39000257004-PACU-157326100%573265-PACU-286811100%868116-PACU-30ERROR:#DIV/0!0Sub-TotalTotal238906221741.04Spare - 20%4778144348Total (VA)286687266089Say (kVA)286.69266.09

IDL =Estimated Demand Load1.732x380=2660891.732 x 380=404.2926461651Amps.

Sizing of Maximum Overcurrent Protective Device (ICB) :ICB =Demand load current x 1.25%

ICB =404.29x1.25ICB =505.4Select,800AT/800AF, Circuit Breaker, 3P , 600 VAC

Sizing of Distribution Panelboard (MDP-FS-CD) Conductors (IC):IC =Full Load Current of MDP-FS-CD x 125% =404.3x1.25=505Amps.

Select2 Set of 1-4/C 300mm2 CU/ XLPE/PVC + 1/C 50 mm2 GND in 2x4" DIA. conduitAmpacity=475NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables in outdoor, 310-16, 250-122 & C9soil temp is 40 deg. C. and from NEC Table 310-16, Correction Factor is0.88Ampacity=Number of Sets xBase AmpacityxCorrection Factor=2x475x0.88=836Amps

Volt-drop Calculations:

From ATS to MDP-FS-CDLength, L-100Meter Full Load Current (I)-404.29AmpsCosq-0.80Sinq-0.60Cable Selected-1-4/C 300 mm2 CU/XLPE/PVCAC Resistance of Cable-0.0812Saudi Cables@ 90 deg. C in Ohm/kMPg. 52Reactance of Cable in-0.0935Saudi CablesOhm/kMPg. 58Number of Sets-2

Volt Drop:Line to Line VR=3x L x Ix(R cos + X sin)(N x1000)

=1.732x 100x404.3(0.0812x0.8+0.094x0.6)(2x1000) VR=4.24Volts

% VD= VRx100V=4.24x100380=1.12< 3%, hence o.k

Fault level calculation

For MDP-FS-CDLength, L-100MetersCable Selected-1-4/C 300 mm2 CU/XLPE/PVCAC Resistance of Cable-0.0812@ 90 deg. C in Ohm/kMReactance of Cable in-0.0935Ohm/kMNumber of Sets (N)-2

Impedance of cable=((R 2 + XL 2)) x N x LOhmZc=0.0248Ohm

Total Impedance from transformer to MDP-FS-CD=Zc + Z Tr

=0.0648Ohm

Isc =kVA1.732xVxZ%

=500=11.7295562795kA1.732x380x6%

For MDP-FS-CD fault level shall be20kA

5.4POWER & LIGHTING PANEL (PLP-FS-CD)


-Continuous Loads1-Lighting11753NEC11753NEC Table 220.11Non-Continuous Loads1-Receptacles11730NEC10865NEC Table 220.132-Electric Water Heater750060%4500Sub-Total1923015365Total3098327118Spare - 20%61975424Total (VA)3718032542Say (kVA)37.1832.54




Sizing of Panelboard (PLP-FS-CD) Conductors (IC):IC =Full Load Current of PLP-FS-CD x 125% =49.4x1.25=62Amps.

Select1-4/C 25 MM2 CU/XLPE + 1/C 6 MM2 GND in 40mm Dia ConduitAmpacity=95According to RC manual, table 7-G, ambient temperature for cables Indoor in ACspaces is 30 deg. C. and from NEC Table 310-16, Correction Factor is1NEC TablesAmpacity=Number of Sets xBase AmpacityxCorrection Factor310-16, 250-122 & C8=1x95x1=95Amps


From MDP-FS-CD to PLP-FS-CDLength, L-5Meter Full Load Current (I)-49.44AmpsCosq-0.80Sinq-0.60Cable Selected-1-4/C 25 mm2 CU/XLPE/PVCAC Resistance of Cable-0.9270Saudi Cables@ 90 deg. C in Ohm/kMPg. 52Reactance of Cable in-0.1072Saudi CablesOhm/kMPg. 58Number of Sets-1


=1.732x 5x49.4(0.927x0.8+0.107x0.6)(1x1000) VR=0.35Volts

% VD= VRx100V=0.35x100380=0.09< 3%, hence o.k


For PLP-FS-CDLength, L-5MetersCable Selected-1-4/C 25 mm2 CU/XLPE/PVCAC Resistance of Cable-0.9270@ 90 deg. C in Ohm/kMReactance of Cable in-0.1072Ohm/kMNumber of Sets (N)-1


Total Impedance from unit transformer to PLP-FS-CD=Zc + Zc (MDP-FS-CD) + Z Tr

=0.0694Ohm

Isc =kVA1.732xVxZ%

=500=10.9413356185kA1.732x380x7%

For PLP-FS-CD fault level shall be14kA

5.5LIGHTING PANEL (LP-FS-CD)


-Continuous Loads1-Lighting24786NEC24786NEC Table 220.11Sub-TotalTotal2478624786Spare - 20%49574957Total (VA)2974329743Say (kVA)29.74100%29.74




Sizing of Panelboard (LP-FS-CD) Conductors (IC):IC =Full Load Current of LP-FS-CD x 125% =45.2x1.25=56Amps.

Select1-4/C 16 MM2 CU/XLPE + 1/C 6 MM2 GND in 25mm Dia ConduitAmpacity=75NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables Indoor in AC310-16, 250-122 & C8spaces is 30 deg. C. and from NEC Table 310-16, Correction Factor is1Ampacity=Number of Sets xBase AmpacityxCorrection Factor=1x75x1=75Amps


From MDP-FS-CD to LP-FS-CDLength, L-65Meter Full Load Current (I)-45.19AmpsCosq-0.80Sinq-0.60Cable Selected-1-4/C 16 mm2 CU/XLPE/PVCAC Resistance of Cable-1.4700Saudi Cables@ 90 deg. C in Ohm/kMPg. 52Reactance of Cable in-0.1068Saudi CablesOhm/kMPg. 58Number of Sets-1


=1.732x 65x45.2(1.47x0.8+0.107x0.6)(1x1000) VR=6.31Volts

% VD= VRx100V=6.31x100380=1.66< 3%, hence o.k


For LP-FS-CDLength, L-65MetersCable Selected-1-4/C 16 mm2 CU/XLPE/PVCAC Resistance of Cable-1.4700@ 90 deg. C in Ohm/kMReactance of Cable in-0.1068Ohm/kMNumber of Sets (N)-1


Total Impedance from unit transformer to LP-FS-CD=Zc + Zc (MDP-FS-CD) + Z Tr

=0.1606Ohm

Isc =kVA1.732xVxZ%

=500=4.7312506739kA1.732x380x16%

For LP-FS-CD fault level shall be14kA

5.6POWER PANEL (PP-FS-CD)


-Non-Continuous Loads1-Receptacles27000NEC18500NEC Table 220.132-Electric Water Heater1200060%7200Sub-Total3900025700Total3900025700Spare - 20%78005140Total (VA)4680030840Say (kVA)46.8030.84




Sizing of Panelboard (PP-FS-CD) Conductors (IC):IC =Full Load Current of PP-FS-CD x 125% =46.9x1.25=59Amps.

Select1-4/C 16 MM2 CU/XLPE + 1/C 6 MM2 GND in 25mm Dia ConduitAmpacity=75NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables Indoor in AC310-16, 250-122 & C8spaces is 30 deg. C. and from NEC Table 310-16, Correction Factor is1Ampacity=Number of Sets xBase AmpacityxCorrection Factor=1x75x1=75Amps


From MDP-FS-CD to PP-FS-CDLength, L-65Meter Full Load Current (I)-46.86AmpsCosq-0.80Sinq-0.60Cable Selected-1-4/C 16 mm2 CU/XLPE/PVCAC Resistance of Cable-1.4700Saudi Cables@ 90 deg. C in Ohm/kMPg. 52Reactance of Cable in-0.1068Saudi CablesOhm/kMPg. 58Number of Sets-1Volt Drop:Line to Line VR=3x L x Ix(R cos + X sin)(N x1000)

=1.732x 65x46.9(1.47x0.8+0.107x0.6)(1x1000) VR=6.54Volts

% VD= VRx100V=6.54x100380=1.72< 3%, hence o.k


For PP-FS-CDLength, L-65MetersCable Selected-1-4/C 16 mm2 CU/XLPE/PVCAC Resistance of Cable-1.4700@ 90 deg. C in Ohm/kMReactance of Cable in-0.1068Ohm/kMNumber of Sets (N)-1


Total Impedance from unit transformer to PP-FS-CD=Zc + Zc (MDP-FS-CD) + Z Tr

=0.1606Ohm

Isc =kVA1.732xVxZ%

=500=4.7312506739kA1.732x380x16%

For PP-FS-CD fault level shall be14kA

5.7PACU-1

Manufacturer:ZamilModel:PAX025Voltage Rating:380VAC/3-Ph/60 Hz

-From Manufacturer's Electrical DataCompressor(RLA)-A:37.8AmpsCompressor(RLA)-B:32.1AmpsComp. Fan Motor (2 Nos.):5.8AmpsEva. Fan Motor (1 Nos.):11.4AmpsTotal Full Load Current:87.1AmpsElectric Heater:15kW(At Unity P.F, kW=kVA)

KVA (rating) =I x Vol x 1.732 1000=87.10x380x1.7321000=57.33kVA

Note:1-Since the Heating and Cooling Operation is not simultaneous and forcalculation purpose, higher load is considered, in this case, coolingload, which is 57.33kVA

Maximum Overcurrent Protective Device (ICB) :ICB =Full Load Current of Motor-Compressor - A x 175% + Full Load Current of Motor-Compressor - B + Comp. Fan Motor Current Ratings + Eva. Fan Motor Current Ratings = (37.80x175%)+(32.10+5.80+11.40)NEC 440.22(B)(1)=115.45AmpsSelect :Manufacturer recommended Maximum Over Current Protection Device is 130 AT,Choose 150AT/200AF , 3-P, 600 VAC Circuit Breaker

Rating of Disconnecting MeansProvide200 Amps, 3-P + GND, 600 VAC, Fusible Disconnect Switch in Nema-4X Encl.

Motor Circuit Feeders (IC):IC =Full Load Current of Motor-Compressor - A x 125% + Full Load Current of Motor-Compressor - B + Comp. Fan Motor Current Ratings + Eva. Fan Motor Current RatingsNEC 440.33

= (37.80x125%)+(32.10+5.80+11.40)=96.55Amps

Manufacturer recommended Minimum Circuit Amps is 96.6A Provide1-3/C 70 MM2 CU/XLPE + 1/C 16 MM2 GND in Cable TrayAttachment-Ampacity=195NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables in air310-16, 250-122 & C8is 50 deg. C. and from NEC Table 310-16, Correction Factor is0.82Ampacity=Number of Sets xBase AmpacityxCorrection Factor=1x195x0.82=159.9Amps


From MDP-FS-CD to PACU-1Length, L-80Meter Full Load Current (I)-87.10AmpsCosq-0.80Sinq-0.60Cable Selected-3/C 70 mm2 CU/XLPE/PVCAC Resistance of Cable-0.3430Saudi Cables@ 90 deg. C in Ohm/kMPg. 52Reactance of Cable in-0.0919Saudi CablesOhm/kMPg. 58Number of Sets-1


=1.732x 80x87.1(0.343x0.8+0.092x0.6)(1x1000) VR=3.98Volts

% VD= VRx100V=3.98x100380=1.05< 3%, hence o.k

5.8PACU-2

Manufacturer:ZamilModel:PAX035Voltage Rating:380VAC/3-Ph/60 Hz

-From Manufacturer's Electrical DataCompressor(RLA)-A:55.7AmpsCompressor(RLA)-B:55.7AmpsComp. Fan Motor (2 Nos.):5.8AmpsEva. Fan Motor (1 Nos.):14.7AmpsTotal Full Load Current:131.9AmpsElectric Heater:30kW(At Unity P.F, kW=kVA)






= (55.70x125%)+(55.70+5.80+14.70)=145.83Amps

Manufacturer recommended Minimum Circuit Amps is 145.8 A Provide1-3/C 95 MM2 CU/XLPE + 1/C 16 MM2 GND in Cable TrayAttachment-Ampacity=225NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables in air310-16, 250-122 & C8is 50 deg. C. and from NEC Table 310-16, Correction Factor is0.82Ampacity=Number of Sets xBase AmpacityxCorrection Factor=1x225x0.82=184.5Amps




=1.732x 70x131.9(0.248x0.8+0.089x0.6)(1x1000) VR=4.03Volts

% VD= VRx100V=4.03x100380=1.06< 3%, hence o.k

5.9PACU-3

Manufacturer:Model:Voltage Rating:VAC/3-Ph/60 Hz

-From Manufacturer's Electrical DataCompressor(RLA)-A:125AmpsCompressor(RLA)-B:125AmpsComp. Fan Motor (2 Nos.):5.8AmpsEva. Fan Motor (1 Nos.):11.4AmpsTotal Full Load Current:267.2AmpsElectric Heater:30kW(At Unity P.F, kW=kVA)






= (125.00x125%)+(125.00+5.80+11.40)=298.45Amps

Manufacturer recommended Minimum Circuit Amps is 142.5 A Provide1-3/C 95 MM2 CU/XLPE + 1/C 16 MM2 GND in Cable TrayAttachment-Ampacity=225NEC TablesAccording to RC manual, table 7-G, ambient temperature for cables in air310-16, 250-122 & C8is 50 deg. C. and from NEC Table 310-16, Correction Factor is0.82Ampacity=Number of Sets xBase AmpacityxCorrection Factor=1x225x0.82=184.5Amps




=1.732x 70x267.2(0.248x0.8+0.089x0.6)(1x1000) VR=8.16Volts

% VD= VRx100V=8.16x100380=2.15< 3%, hence o.k

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