staking course1
DESCRIPTION
Electric Line Survey TrainingTRANSCRIPT
Distribution Staking and Line Design Course
REA Tanzania
Welcome
During my 15 years of overseas experience I have designed and built more than 1,000 kilometers
of distribution line in 12 countries.
That is a lot of walking
Welcome
My name is Md Maruf Hasan
I will be your instructor for this course.
Welcome
Assisting me is Osman Hussein
&
Hussein Shamdas
Rules of the Course
• Attendance is taken daily
• No cell phone use - turn them off
• Phones may be used during breaks
• There will be quizzes/examinations
• There will be field exercises
Quizzes will be graded
• Points are given for correct answers
• Partial correct answers are awarded points
• Incorrect answers receive negative points (do not guess)
• Quiz points for the course are accumulative
What you will need
• Wear comfortable work shoes
• Bring a hat
• Bring a memory stick if you want copies of material
Pole Ground Line
Pole Length
m
Pole Class
Rated Breaking Strength*-
Nt
Ground line location**
m
9 Medium 6,300 1.5
11 Medium 7,700 1.8
12 Medium 8,000 2
13 Medium 10,000 2
* Load at 0.6m below pole top that breaks pole at the ground line**Distance from pole butt in meters.
Conductor Ruling Span
Ruling and Limit Spans for 33kV lines
Conductor Code Name
Ruling Spanm
Limit spansm
Hare 90 105Hare 50* 71Rabbit 120 145Rabbit 50* 71Gopher 120 145Gopher 50* 71Shrike 175 210Shrike 50* 71Periwinkle 50 71
Slide 10/82
* When used with underbuild LV line or in areas where LV underbuild may be anticipated in the near future.
Conductor Uplift
Conductor
ACSR
(Aluminum Conductor Steel Reinforced)
APPLICATIONS
Used as bare overhead transmission cable and as primary and secondarydistribution cable. ACSR offers optimal strength for line design. Variable steelcore stranding enables desired strength to be achieved without sacrificingampacity.
Conductor
AAAC
(All Aluminum Alloy Conductor)
APPLICATIONS
Used as bare overhead conductor for primary and secondary distribution.
Designed utilizing a high-strength aluminum alloy to achieve a high strength-to-weight ratio; affords better sag characteristics.
Aluminum alloy gives AAAC-6201 higher resistance to corrosion than ACSR.
LV Cables
Triplex
Conductor
Automatic splice
Conventional Meter
Meter
Line Material
These are galvanized washers
- Curved Square Washer
- Square Washer
- Round Washer
Line Material
Anchor Shackle
Line Material
Eyenut
Line Material
Curved Lock Nut
Line Material
Eyebolt (Oval Eyebolt)
Line Material
Machine Bolt
Line Material
Preformed Deadend
Line Material
Distribution Cutout
Line Material
Lightning/Surge Arrester
IntroductionPart I - Line Design
This course deals with Line Design in the field through the use of a methodology called ‘Staking’
What is Staking?
The process of staking takes the task of line design from the office to the field. Using tables, illustrations and guidelines the staking engineer is able to construct a safe, reliable, and economical distribution line.
Why is it called Staking?
Stakes, usually made of wood, are used to make the location of the structures.
Staking
The staking of a distribution line consists of the selection of the various physical components, including conductors, poles, pole-top assemblies, guys, anchors, etc. that comprise distribution structures.
Staking
Staking though, is not simply the placement of wooden stakes in the ground.
Staking is the a complete engineering evaluation of the choice of each structure and its location prior to driving the first stake
Staking
This is a Stake
Construction Unit
A construction or assembly unit is a specific component that is installed as part of the building block to construct an entire distribution structure. Each assembly drawing is made of materials and has stated limitations of design
Construction Drawing
• Dimensions of the components of the assembly.
• Design limits and recommendations.
• Bill of materials required for construction.
Construction Drawing• C1 0° - 5°• C2 5° - 30° Rabbit 50 mm2
• C2 5° - 15° Dog 100 mm2
• C2 5° - 10° Wolf 150 mm2
• C3 25° - 60°• C4/2C7 60° - 150°• C7 Horizontal Deadend• C8 Double Deadend
Construction Drawing
This is a 3Ø assembly. It is designed to support conductor from 0° to 5°. It is designated as C1.
The pole is not part of the unit
Construction as Built
Construction Drawing
This is a 3Ø vertical assembly. It is designed to support conductor from 30° to 60°. It is designated as C3.
Construction Drawing
This is a guy (stay) assembly. It is designed to support a pole at angles or deadends. It is designated as E1.
Construction Drawing
This is an anchor assembly. It is designed to work in conjunction with a guy (stay) at angles or deadends. It is designated as F1.
Construction Safety
• Adequate clearance & separation between conductors.
• Clearances to meet TANESCO requirements for jumpers, and climbing and working space.
• Clearances to permit safe hot line work.
Construction Safety
• High impulse strength for the outer phases through the use of wood crossarms.
• Minimal radio and TV interference by providing generous separation of phase associated hardware from grounded conductors and/or hardware.
Staking Sheet
• A staking sheet should be prepared to fully describe the construction for the proposed line.
• Typically, a staking sheet will include as a minimum the following data:
Staking Sheet
• Name of job
• Name of staking technician
• Date when staked
• Sheet number
• GPS points
• Construction Assemblies
• Span lengths
• Conductor size & type
• Line angle
Staking Sheet
Desingned by:
Substaton: Substation Feeder:
Date Ground
Map grid No(s) Lead Cap
Sheet No. of M. kVA
Column Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 18 19 20SKETCH OF WORK
Qty Qty Qty.
PROJECT: AREA Kilombero/Mbozi STAKING SHEETBuilt by:
GPS. No.
POLES PRIMARY SECONDARY GUYS ANCHOR Xfmr.Removal
UnitObservations
and notesSize/ Class
Angle Back Span
UnitCond Size
Back Span
Unit UnitCond Size
Unit Unit Qty. Unit Qty.
LCDP in Tanzania,
Misc Units
Unit Qty
Page Totals
Removal Units
Item
Condcutor
21
Item
New Units
New Units
Item
Poles
Staking SheetPole Numbering
Staking SheetPole Numbering
Example: EC-EH-22-5-Bad
EC EH 22 5 B a d
Substation Feeder Pole no. Tap LV lv lv
Substation – A two-letter designation is assigned to all 11 kV and 33 kV substations. Feeder – A two-letter designation is assigned to all 11 kV and 33 kV substation feeders.
Staking SheetPole Numbering
Example: EC-EH-22-5-Bad
EC EH 22 5 B a d Substation Feeder Pole no. Tap LV lv lv Pole no. – The pole no. is the correlative number of the pole of a particular feeder . If two poles exist at the same location such as a transformer or equipment location where the two poles are physically connected by a platform, then a decimal point and number will be added i.e. EC-EH-22-2.1 and EC-EH-22-2.2. If a pole is inserted at a later date then a decimal point and number will also be added.
Tap (optional) – If there is a primary line tap from a feeder, then a number will be used after the corresponding Pole no. Otherwise the space will be blank. If there is a tap from a tap, again a number designation will be assigned after the corresponding Tap pole number designation.
Staking SheetPole Numbering
Example: EC-EH-22-5-Bad EC EH 22 5 B a d
Substation Feeder Pole no. Tap LV lv lv
LV – An Upper-case letter will be used to designate the secondary feeds from a transformer. Facing north and moving clockwise, the first secondary LV feed will be ‘A’, the next in rotation will be ‘B’ and so forth. lv – A lower-case letter will be used to designate the pole position along the feed. Aa would be the first secondary pole on the A feed. Bb would be the second pole along the B feed, and so forth. lv - Additional lower-case letter(s) will be used to designate a secondary tap or derivation from a secondary feed. Bad indicates that from the third pole of secondary feed B there are four additional poles to arrive at Bad.
Staking SheetLine Sketch
• Route of the line to built
• Poles
• Guys and Anchors
• Transformers
• Taps
• Sectionalizing Devices
• Secondary Line
• Open Points
Staking SheetLine Sketch
These symbols are used when preparing the sketch on the staking sheet.
Staking Sheet
Staking Sheet
Staking Sheet
Staking Sheet to Material List
Use interactive UniCalc
Staking Crew Equipment
• Hammer, 1 kg. • Spray Paint
• Nails, 6” MS • Back Pack
• Nails, 3” Concrete • Theodolite & Tripod
• Bottle Caps • Tape 10 m & 100 m
• Pencils & Markers • Staking Template
• Traffic Cones • Staking Form Holder
• Safety Vests • Measuring Stick 10 m
• Hats • Hand Level
• Machete • Water Thermos