Live Line Maintenance Tec Hniques

8/10/2019 Live Line Maintenance Tec Hniques

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HOT LINEMAINTENANCE

EQUIPMENT (T&P)

PRESENTED BYT T LAWALESUPERINTENDING ENGINEER

EHV O&M CIRCLE

AURANGABAD


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Methods followed

Conventional

Live Line Maintenance


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History of LLMT Development

Hot Line Maintenance, as the name implies, workingon a line while energized to inspect and replace, ifnecessary, defective parts to avoid costly forcedoutages.

The principle of Hot Line Maintenance could besaid to have been first introduced long ago whendisconnect sticks were used to open energizedswitches on distribution lines. The operation provedthat log dry poles could be equipped with fittings,which could enable linemen to work safely on LiveLines. However, it was many years later this idea was

used to develop tools for Hot Line Maintenance work.


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History of LLMT Development

1913 First hot line tools were made in Wapakoneta,Ohio, USA. Wooden sticks were used. They arecrude, bulky and difficult to handle.

1960- The tools were used on 400 kv. Also Bare Handmethod introduced.

1958 - Introduced in India. Also two Hot Line TrainingCentre for voltage levels up to 110 kv were

established one at Bangalore and other at Ganguwal(Punjab).

1974- Training Centre restarted at Bangalore forvoltage levels up to 220 kv.


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Classification of Live Line

Maintenance

Hot stick Method:-In this method the lineman will be at ground

potential working with Hot Sticks (tools)

keeping safe clearance from the line.

Bare Hand Method:-

Here the lineman will be working at linepotential keeping safe clearance from ground.

Combination of Both Metod


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Classification on the basis of

Voltage Level

1. 11Kv to 220 Kvusing Hot stick Method

2. 400Kv and above using Bare Hand andCombination Method


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Basic Requirement

Training

Awareness

Proper Tools and Parts (T&P)


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Comparison With Conventional

Method

Requirement oftools

1. Metal Hardware

made up of MildSteel, Cast iron etc

2. Rope of deferent

sizes shall have goodmechanical strength.

Requirement of Tools

1. Metal Hardware butmade up of

Aluminum alloy2. Rope shall have high

dielectric andmechanical strength

3. Insulated Stick calledFRP


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Comparison

Conventional Method: This is break downMaintenance

Observation

Damage or break down of electrical device

Interruption of flow of current

Customer


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Live Line Maintenance

This is called preventive maintenance

Locating fault early stage and rectifying

Methods of locating Fault

1 By visual inspection: a) Bare Eye b) usingBinocular

2 Patrolling:- Day and Night

3. Using Testing equipment:- Live LineInsulator Testing Instruments,Thermotector etc.


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HOT LINE TOOLS Hot lines tools refer to hot sticks used to carry

out hot line works. They have to be light inweight but mechanically strong and highlyinsulated (Dielectric strength).

EPOXY GLASS STICKS

It is made up of thousands of epoxy glassresin impregnated glass fibre laid length wiseand wound wise on a unicellular glass foam

core, which is made up of millions ofunconnected cells filled with inert gas. (Theinert gas inhabits moisture absorption andcondensation)


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Types of Epoxy Tools and its

loading capacities Lever Lift saddle

Wire Tongs

Gripall sticks

6 length for

8 length for

10 length for

12 length for

Tie Stick Ladder

Utility platform

Universal stick

Wire cutter

1500 lbs

11 kv

33 kv

66, 110 kv

220 kv

750 lbs. Available in 36 & 42. Itwill be used on poles with the

safer distance for working of linemen.


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Other Tools:

Hot Clamp

Conductor cover, insulatorcover, cross arm cover

Utility Plat Form

Epoxy glass rail plat formwith the provision to tie thesafety rope.

Hand gloves

Tarpaulin

Hot Stick Ladder

Snub ropes

Set of rope blocks

Safety Belt

Metal / Rope sling

Cradle


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Metallic Tools (Aluminium Alloy)

Pole Saddle

Cross arm saddle

Tower Saddle

Above saddles with 4 extn.

Lever lift saddlecan life up

to 20

Rope snubbing bracket

Hand line hook

Tension puller

Tower yoke

Steel arm yoke

Two pole strain carrier of 8,10, 12, 15 length having 2dia

Single strain carrier pole

Cuma - long clamp

Hand Line Pully


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Punctured Insulator Detection


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Live Line Insulator Testing


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Major Maintenance Work to be

carried out

Replacement Of Insulator:-

1. Suspension

2. Tension3. Pilot Insulator

4. Double String

5. Pin Insulator in case of Pole Structure


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Continuation

Nut Bolt Tightening, Replacement

Providing Bypass Jumper

Replacement of Jumper Fixing of Vibrating Damper

Tree branches cutting, pruning

Oiling of nut bolt, liquid spray for contactcleaning


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continuation

Binding of damaged conductor

Live Line Insulator Testing

Live Line Insulator Washing etc.


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66 Kv Suspension Insulator

Re[placement


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Removed Broken Insulator


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Replaced with insulator


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High Pressure Washing


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220 Kv Tension Point Operation


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Bare Hand Work In Substation


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50 ft Reach through scaffolding


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scaffolding


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Reaching to conductor through Hot

man Chair


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Sending Hot Man by Chair


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SAFETY RULES Only authorized persons (Certificate Holders)

should do hot line maintenance. Make sure that weather is clear and there is no

chance of rain.

Make proper plan to carry out the work inadvance. Line should clearly understand theoperation with drawing, tools used etc. Inspect

the tools to be used and clear all the tools. See that the pole is strong enough to take the

load of crew and the tools.


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SAFETY RULES Remove wrist watch or other ornaments before

climbing the pole. Equip yourself with helmet, safety shoes

(conductive shoes) and safety belt.

Do not climb towards the jumper; if clearanceis less. Push the jumper or cover it withinsulated guards.

Take proper position on the pole and ensurethat you are safe to work with both hands.

Keep high degree of co-ordination among all of

you while working.


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SAFETY RULES Do not loose temper, work clam and cool even if it is

time consuming. If anybody on the pole/tower wants to change his

position, he should tell his colleague and to the in-charge before doing so.

While working clear all doubts what so ever regardingthe work immediately with the in-charge.

Ground person should not come under the work spot

to avoid any accident. In-charge of work should not do work with his own

hands. He should take such a position on the groundfrom where he can see all the working persons and

should instruct them properly.

SAFE WORKING DISTANCE FOR


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SAFE WORKING DISTANCE FOR

HOT LINE OPERATIONSVoltage rage phase to phase in kv FEET METRE

2.1 to 15

2

0.61

15.1 to 35 24 0.71

35.1 to 46 26 0.76

46.1 to 72.5

2

0.9172.6 to 121 34 1.02

138 to 145 36 1.07

161 to 169 38

1.12

230 to 242 5 1.52

345 to 362 7 2.13

500 to 552 11 3.35

700 to 765 15 4.57


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Effect of current flow in body:

0 1 mA

Cannot feel anything

1 8 mA Can feel but no pain

8 12 mA Painful but can let it go.

12 20 mA

Freeze, cannot let go20 50 mA Breathing stops

50 200 mA Heart stops

200 and above

Sever Burns


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Safety Work Permit

Safety Permitis a mandatory document andnobody will in any circumstances over ride theauthority of Permit To Work

Working Permit is a document givingpermission for specific work to be carried outsubject to certain stated conditions with inspecified time.

Safety Permit is one of the tool for controlling

hazards.

Working permit- it means permit to work


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Working permit- it means permit to workunder live (charged) circumstances.

Working permit information of Hot line workshould be given to the Load Dispatch well inadvance by S/S or Line officials.

While issuing a working permit to the Hot Line

official it is important to check whether Autoreclosure is in service or not. (applicable forLine).

If it is in service then it should be made off.So in case of any reason it may not getcharged again.


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THANK YOU

Documents

Live Line Maintenance Tec Hniques