Sub Station Abstract- (Part-3)


Electrical Wire Ground Clearance:

  • Ground Clearance in Meter = 5.812 + 0.305 X K

  • Where K= (Volt-33) / 33
Voltage Level Ground Clearance
<=33KV 5.2  Meter
66KV 5.49 Meter
132KV 6.10 Meter
220KV 7.0   Meter
400KV 8.84  Meter

Overhead Conductor /Cable Size:

Voltage

Overhead Conductor

Cable Size

33 KV ACSR-Panther/Wolf/Dog , AAAC 150,185,300,400,240 mm2 Cable
11 KV ACSR-Dog/Recon/Rabbit , AAAC 120, 150,185,300 mm2 Cable
LT ACSR-Dog/Recon/Rabbit , AAC,AAAC 95,120, 150,185,300 mm2 Cable

 Transmission / Distribution Line:

Span

Height of Tower

400KV=400 Meter

400KV=30Meter (Base 8.8 Meter)

220KV=350 Meter

220KV=23Meter (Base 5.2 Meter)

132KV=335 Meter

220KV Double Circuit=28 Meter

66KV=210 Meter

66KV=13Meter

Conductor Ampere

Voltage wise Conductor

Dog=300Amp

400KV=Moose ACSR=500MVA Load

Panther=514Amp

220KV=Zebra ACSR=200MVA Load

Zebra=720Amp

132KV=Panther ACSR=75MVA Load

Rabbit=208Amp

66KV=Dog ACSR=50MVA Load

Moose=218Amp

 

 Type of Tower:

Type

Used

Angle/Deviation

A

Suspension Tower Up to 2°

B

Small Angle Tower 2° to 15°

C

Medium Angle Tower 15° to 30°

D

Large Angle / Dead End Tower 30° to 60° & Dead End

 Tower Swing Angle Clearance (Metal Part to Live Part):

Swing Angle

Live Part to Metal Part Clearance (mm)

66KV

132KV

220KV

400KV

915mm

1530mm

2130mm

3050mm

15°

915mm

1530mm

2130mm

22°

3050mm

30°

760mm

1370mm

1830mm

44°

1860mm

44°

610mm

1220mm

1675mm

Corona Ring Size:

Voltage

Size

<170 KV 160mm Ring put at HV end
>170 KV 350mm Ring put at HV end
>275 KV 450mm Ring put at HV end & 350 mm Ring put at Earth end

 

Span of Transmission Line (Central Electricity Authority):

Voltage

Normal Span

765 KV

400 to 450 Meter

400 KV

400 Meter

220 KV

335,350,375 Meter

132 KV

315,325,335 Meter

66 KV

240,250,275 Meter

 

 

Electrical Costing (Per Sq.Ft) Quick Reference


 

Load in Multi-storied Building (Madhyanchal Vidyut Vitran Nigam)

Type of Load

Calculation

Diversity

Domestic  (Without Common Area)

50 watt / sq. meters

0.5

Commercial  (Without Common Area) 150 watt / sq. meters

0.75

Lift, Water Pump, Streetlight ,Campus Lighting ,Common Facilities,

Actual load shall be calculated

0.75

 

Load in Multi-storied Building (Noida Power Company Limited)

Type of Load

Calculation

Diversity

Domestic (Constructed area) 15 watt / sq. Foot

0.4

Commercial(Constructed area) 30 watt / sq. Foot

0.8

Industrial (Constructed area) 100 watt/ 1 sq. Foot

0.5

Lift, Water Pump, Streetlight ,Campus Lighting ,Common Facilities, 0.5Kw / Flat

 

Voltage Drop: 2% Voltage drop from Transformer to Consumer end.

T&D Losses: 2% T&D Losses from Transformer to Consumer end.

 

Approximate % Cost or Sq.Foot Cost

Project Item

% of Total Project Cost

Rs per Sq.Foot

Articheture (Consultancy)

0.7%

13.1 Rs / Sq.Foot

Structural (Consultancy)

1.2%

21.8 Rs / Sq.Foot

Service Design (Consultancy)

0.4%

7.2 Rs / Sq.Foot

Fire Fighting Work

1.3%

23 Rs / Sq.Foot

Electrical Work (Internal)

4.1%

76 Rs / Sq.Foot

Lift Work

4.4%

82 Rs / Sq.Foot

 

Street Light Costing (CPWD-2012)

Fluorescent Lamp

95 Rs/Sq.Meter

With HPMV Lamp

130 Rs/Sq.Meter

With HPSV Lamp

165 Rs/Sq.Meter

Electrical Sinage

85 Rs/Sq.Meter

 

Other Electrical Cost

Area Required for Solar Light

10 Watt/Sq.Foot

Solar Power Installation

1.5 Lacs Rs/1Kw

HVAC Cost

18 Watt/Sq.Foot

 

Distribution Losses (Gujarat Electricity Board)

Voltage (Point of Injection)

At 11 KV

Point of Energy Delivered

11KV / 22KV / 33KV

10%

10.82%

400 Volt

16.77%

Size of Ventilation Shaft:

Height of Building in meter Size of ventilation shaft in sq meter Minimum size of shaft in meter

9.0

1.5

1.0

12.5

3.0

1.2

15 and above

4.0

1.5

 

Rate Analysis (CPWD-2012)

Description

Amount
Sub Station Equipment 7000 Rs/ KVA
D.G Set with installation 1000 Rs / KVA
UPS with 30min Breakup 20000 Rs / KVA add 8000 Rs / KVA additional each 30 min
Solar Power Generation 1.25 Lacs / KW
Solar Water System (200Liter/Day) 46000 Rs
Solar Water System (300Liter/Day) 64000 Rs
Solar Water System (1000Liter/Day) 210000 Rs
Central AC Plant 75000 RS / Ton
VRF / VRV System 55000 Rs / HP
Air condition System 11000 Rs / Ton
CCTV System 300 Rs / Sq Meter
Access Control system 200 Rs / Sq Meter
Hydropenumatic Water system 2000 Rs / LPM
Building Management System 300 Rs /  Sq Meter add 100 Rs / Sq Meter additional area beyond 10000 Sq Meter

 

Rate Analysis (Rs per Sq. Meter) (CPWD-2012)

Work

Office/College/Hospital

School

Hostel

Residence

Fire Fighting (with Wet Riser)

500

500

500

500

Fire Fighting (with Sprinkler)

750

750

750

750

Fire Alarm (Manually)

300

Fire Alarm (Automatic)

500

500

500

500

Pressurized  Mechanical Ventilation

650

650

650

650

 

Rate Analysis (% of Total Project Cost) (CPWD-2012)

Work

Office/College/Hospital

School

Hostel

Residence

Internal Water Supply & Sanitary

4%

10%

5%

12%

Internal Electrical Installation

12.5%

12.5% 12.5% 12.5%

 

Lift Speed (Indian Army Manual)

No of Floor

Lift Speed

4 to 5

0.5 to 0.7 meter/Sec

6 to 12

0.75 to 1.5 meter/Sec

3 to 20

1.5 to 2.5 meter/Sec

Above 20

 Above 2.5 meter/Sec

 

Lift  Details (CPWD-2012)

Type of Lift 

Persons

Weight

Speed  M/Sec

Travel

Price

Add Rs /Floor

Passenger Lift 

8 Person 544 Kg 1.0 G+4 18 Lacs 1.25 Lacs

Passenger Lift 

13 Person 844 Kg 1.5 G+4 22 Lacs 1.25 Lacs

Passenger Lift 

16 Person 1088 Kg 1.0 G+4 28 Lacs 1.50 Lacs

Passenger Lift 

20 Person 1360 Kg 1.5 G+4 30 Lacs 1.50 Lacs

 Approximate Load as per Sq.ft Area (As per DHBVN):

Sq.ft Area Required Load (Connected)
< 900 Sq.ft 8 KW
901 Sq.ft to 1600 Sq.ft 16 KW
1601 Sq.ft to 2500 Sq.ft 20 KW
> 2500 Sq.ft 24 KW
For Flats :100 Sq.ft / 1 KW
For Flats USS /TC: 100 Sq.ft / 23 KVA

Load as per Sq.Ft:

Type of Load

Load/Sq.Ft

Diversity Factor

Industrial

1000 Watt/Sq.Ft

0.5

Commercial

30 Watt/Sq.Ft

0.8

Domestic

15 Watt/Sq.Ft

0.4

Lighting

15 Watt/Sq.Ft

0.8

Contracted Load in case of High-rise Building:

For Domestic Load 500 watt per 100 Sq. foot of the constructed area.
For Commercial 1500 watt per 100 Sq. foot of the constructed area
Other Common Load For lift, water lifting pump, streetlight if any, corridor/campus lighting and other common facilities, actual load shall be calculated
Staircase Light 11KW/Flat Ex: 200Flat=200×11=2.2KW

Sanctioned Load for Building

Up to 50 kW The L.T. existing mains shall be strengthened.
50 kW to 450 kW (500 kVA) 11 kV existing feeders shall be extended if spare capacity is available otherwise, new 11 kV feeders shall be constructed.
450 kW to 2550 kW (3000 kVA) 11 kV feeder shall be constructed from the nearest 33 kV or 110 kV substation
2550 kW to 8500 kW (10,000 kVA) 33kV feeder from 33 kV or 110 kV sub station
8500 kW (10,000 kVA) 110 kV feeder from nearest 110 kV or 220 kV sub-station

Calculate Technical Losses of Transmission / Distribution Line:


Introduction:

  • There are two types of Losses in transmission and distribution Line.
  • (1) Technical Losses and
  • (2) Commercial Losses.
  • It is necessary to calculate technical and commercial losses.Normally Technical Losses and Commercial Losses are calculated separately .Transmission (Technical) Losses are directly effected on electrical  tariff but  Commercial losses are not implemented to all consumers.
  • Technical Losses of the Distribution line mostly depend upon Electrical Load, type and size of conductor, length of line etc.
  • Let’s try to calculate Technical Losses of one of following 11 KV Distribution Line

Example:

  • 11 KV Distribution Line have following parameter.
  • Main length of 11 KV Line is 6.18 Kms.
  • Total nos. of Distribution Transformer on Feeder 25 KVA= 3 No, 63 KVA =3 No,100KVA=1No.
  • 25KVA Transformer Iron Losses = 100 W, Copper Losses= 720 W, Average LT Line Loss= 63W.
  • 63KVA Transformer Iron Losses = 200 W, Copper Losses= 1300 W, Average LT Line Loss= 260W.
  • 100KVA Transformer Iron Losses = 290 W, Copper Losses= 1850 W, LT Line Loss= 1380W.
  • Maximum Amp is12 Amps.
  • Unit sent out during to feeder is  490335 Kwh
  • Unit sold out during from Feeder is 353592 Kwh
  • Normative Load diversity Factor for Urban feeder is 1.5 and for Rural Feeder is 2.0

Calculation:

Total Connected Load=No’s of Connected Transformer.

  • Total Connected Load= (25×3) + (63×3) + (100×1).
  • Total Connected Load=364 KVA.

 Peak Load = 1.732 x Line Voltage x Max Amp

  • Peak Load = 1.732x11x12
  • Peak Load =228 KVA.

 Diversity Factor (DF) = Connected Load (In KVA) / Peak Load.

  • Diversity Factor (DF) = 364 /228
  • Diversity Factor (DF) =1.15

 Load Factor (LF)= Unit Sent Out (In Kwh) / 1.732 x Line Voltage x Max Amp. x P.F. x 8760

  • Load Factor (LF)=490335 / 1.732x11x12x0.8×8760
  • Load Factor (LF)=0.3060

 Loss Load Factor (LLF)= (0.8 x LFx LF)+ (0.2 x LF)

  • Loss Load Factor (LLF)= ( 0.8 x 0.3060 x 0.3060 ) + (0.2 x 0.306)
  • Loss Load Factor (LLF)= 0.1361

 Calculation of Iron losses:

  • Total Annual Iron loss in Kwh =Iron Loss in Watts X Nos of TC on the feeder X8760 / 1000
  • Total Annual Iron loss (25KVA TC)=100x3x8760 /1000 =2628 Kwh
  • Total Annual Iron loss (63KVA TC)=200x3x8760 /1000 =5256 Kwh
  • Total Annual Iron loss (100KVA TC)=290x3x8760 /1000 =2540 Kwh
  • Total Annual Iron loss =2628+5256+2540 =10424Kwh

 Calculation of Copper losses:

  • Total Annual Copper loss in Kwh =Cu Loss in Watts XNos of TC on the feeder LFX LF X8760 / 1000
  • Total Annual Copper loss (25KVA TC)=720x3x0.3×0.3×8760 /1000 =1771 Kwh
  • Total Annual Copper loss (63KVA TC)=1300x3x0.3×0.3×8760 /1000 =3199 Kwh
  • Total Annual Copper loss (100KVA TC)=1850x1x0.3×0.3×8760 /1000 =1458 Kwh
  • Total Annual Copper loss =1771+3199+1458=6490Kwh

 HT Line Losses (Kwh)=0.105 x (Conn. Load x 2) x Length x Resistance x LLF /( LDF x DF x DF x 2 )

  • HT Line Losses= 1.05 x(265×2) x 6.18 x 0.54 x 0.1361 /1.5 x 1.15 x1.15 x 2
  • HT Line Losses = 831 Kwh

 Peak Power Losses= (3 x Total LT Line Losses) / (PPLxDFxDFx 1000)

  • Peak Power Losses= 3 x (3×63+3×260+1×1380) /1.15 x 1.15 x 1000
  • Peak Power Losses= 3.0

 LT Line Losses (Kwh)= (PPL.) x (LLF) x 8760

  • LT Line Losses = 3 x 0.1361 x 8760
  • LT Line Losses = 3315 Kwh

 Total Technical Losses= (HT Line Losses + LT Line Losses + Annual Cu Losses + Annual Iron Losses)

  • Total Technical Losses = ( 831+ 3315 + 10424 + 6490)
  • Total Technical Losses = 21061 Kwh

% Technical Loss= (Total Losses) / (Unit Sent Out Annually) x 100

  • % Technical Loss= (21061/490335) x100= 4.30%

% Technical Loss=4.30%

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