PRESENTATION ON LIVE-LINE MAINTENANCE Submitted by:NAME PROGRAMME - GAURAV KUMAR - B.TECH EEE INDEX INTRODUCTION HISTORY BASIC TERMS USED a) Barehand Technique b) Conductive Clothing c) Grounded d) Hazard e) Hotstick Technique f) Job Supervisor g) Min Approach Distance h) Nonconductive Rope i) Safety j) Worker POSITIONING OF WORKERS WORKERS SWUNG DIFFERENT WAYS OF LINE MAINTENANCE GENERAL PRECAUTIONS REFERENCES INTRODUCTION The term live-line maintenance includes maintenance activities using the hot stick or the bare hand technique. Fig 1.1:- Hotstick technique Fig 1.2 :- Barehand technique Live-line maintenance is a procedural activity and does not include such activities as switching, climbing inspection, conductor stringing. Maintenance activities performed on energized conductors or equipment with a phase-to-phase voltage exceeding 600 volts by the hotstick technique or 69 kV by the barehand technique. Fig 1.3 :- Hotstick method Fig 1.4 :- Barehand method In electrical engineering, live-line working is the maintenance of electrical equipment, often operating at high voltage, while the equipment is energized. HISTORY In 1916, a tool that was known as an “electrical hook” was introduced in Atlanta. This was essentially a spring-type clamp for tapping energized circuits. Fig 1.5 :- Electrical hook In 1959, live-line tools with fiberglass poles were introduced. The fiberglass consists of layers of resin coated glass fibers wound around and laid lengthwise over a plastic foam core. It is highly resistant to moisture absorption and damage and can maintain 345-kV, 500-kV, and 765-kV transmission lines. Live-line tools were first accepted for work on lines up to 34 kV, but many linemen were hesitant to perform operations on this voltage and because of fear so they switch to 34kV 22kV 66kV 110kV 220kV BASIC TERMS USED Barehand Technique - Live-line work performed by placing the worker at the same potential as the conductor. Conductive Clothing - Metallic protective clothing worn by electrical workers. Fig 1.6 :- Clothing Grounded - Connected to earth or to some conducting body that serves in place of the earth. Hotstick Technique - Live-line work performed by a worker placed at ground potential. Hazard -Anything which can potentially endanger personnel and impair safe working conditions. Nonconductive Rope - A flexible rope of twisted or braided synthetic polymer fibers maintained in a clean dry condition for use in conjunction with live-line maintenance. Fig 1.7 :- Nonconducting rope Job Supervisor - Any person authorized to request, receive, and release Clearances and Orders. Min Approach Distance - The minimum working distance from energized conductors and equipment for personnel. Safety - The art of performing any activity in an accident-free manner. Fig 1.8 :- Safety Fig 1.9 :- Safety hook Worker - Any person authorized to inspect, service, repair, or otherwise be in contact with equipment. Total 9 wears during high voltage operation Fig 1.10 :- Worker POSITIONING OF WORKERS I N S U L A T E D B O O M Where, Fig 1.11 DA = Distance between the worker envelope and uninsulated truck and insulated boom components E = Worker envelope = 4 foot radius D = Greater than or equal to the minimum electrical approach distance WORKERS SWUNG I N S U L A T E D L A D D E R Where, Fig 1.12 DT = Total minimum electrical approach distance with worker in the envelope. E = Worker envelope = 4 foot radius D = Greater than or equal to the minimum electrical approach distance DIFFERENT WAYS OF LINE MAINTENANCE Fig 1.13 :- Helicopter mode Fig 1.14 :- Swinging and climbing mode GENERAL PRECAUTIONS Calculation of minimum approach distances should be taken into account. Transmission systems are often fitted with coordinated protection devices which are circuit breakers that automatically attempt to remake a circuit after a fault. An electric arc is extremely bright, including in the ultraviolet, and can cause arc eye, a painful and potentially blinding condition. Workers may be provided with appropriately tinted goggles that protect vision in the event of a flash. It is usually required that more than one worker be present on site when working on live equipment above a specified voltage. The work may be postponed if adverse weather conditions such as lightning or rainfall. REFERENCES ALL THE TOPICS ARE TAKEN FROM:1. Internet source
