Electrical Safety Standards for Substations

<p>They should be filled with sand or pebbles. (A)</p> Signup and view all the answers

<p>765 kV (D)</p> Signup and view all the answers

<p>Substations with overhead lines (C)</p> Signup and view all the answers

<p>Exposure to hazardous chemicals (B)</p> Signup and view all the answers

<p>Electricity itself is not visible and its effects can be sudden and unexpected. (C)</p> Signup and view all the answers

<p>To prevent electric shock by providing a safe path for current to flow to the ground. (C)</p> Signup and view all the answers

<p>A sudden discharge of electricity from a live part to a grounded object or person, creating an arc. (D)</p> Signup and view all the answers

<p>They can spread quickly and release poisonous gases, causing serious health risks. (B)</p> Signup and view all the answers

<p>Providing adequate training to employees on electrical safety procedures. (A)</p> Signup and view all the answers

<p>5.8 meters (A)</p> Signup and view all the answers

<p>Incipient fault protection (D)</p> Signup and view all the answers

<p>5.2 meters + 0.3 meters for every 33,000 volts or part thereof exceeding 33,000 volts (C)</p> Signup and view all the answers

<p>Class A (B)</p> Signup and view all the answers

<p>Suffocation (C)</p> Signup and view all the answers

<p>Insurance coverage (C)</p> Signup and view all the answers

<p>Short circuits (B)</p> Signup and view all the answers

<p>To simplify earth fault detection (A), To ensure balanced three-phase supply (B)</p> Signup and view all the answers

<p>Increases over voltages during lightning (A)</p> Signup and view all the answers

<p>They are minimized or eliminated (C)</p> Signup and view all the answers

<p>In every workplace (D)</p> Signup and view all the answers

<p>To prevent electric shock to personnel. (A)</p> Signup and view all the answers

<p>Equipment earthing protects workers, while system neutral earthing ensures system stability. (A)</p> Signup and view all the answers

Relationship between actions and their outcomes in accidents or phenomena.

Injury from direct contact with live electrical conductors.

Injuries caused by electrical flashovers from live parts.

Risks of falling from heights or due to electrical shocks.

Catastrophic failures in oil-filled or gas-filled electric components.

Fires caused by loose connections, short-circuits, and electric arcs.

Danger from the release of harmful liquids or gas due to electrical incidents.

Immediate assistance provided during electrical accidents to minimize harm.

Connection of electrical equipment to the ground for safety.

Metal parts that normally do not carry electrical current.

Benefits include safety from shock and proper discharge of currents.

Unwanted electrical current that flows through insulation.

Current produced in a conductor due to proximity to a power circuit.

The neutral point in a three-phase AC system where phases meet.

Connecting the star point of a three-phase system to the earth.

Connecting the neutral point of a power system to ground.

An alarm and tripping system for transformers rated 1000 kVA and above.

Protection method for transformers 10 MVA+ against incipient faults.

Safety measure for generators 100 kVA+ against earth faults or leakage.

A method used to protect generators 1000 kVA+ from faults within their windings.

Height specifications for overhead conductors to prevent accidents.

Minimum height of 5.5-5.8 meters for overhead low and medium voltage conductors.

Minimum height of 5.8-6.1 meters for overhead high voltage conductors.

Height above ground must be 5.2 meters plus 0.3 meters for every 33,000 volts above 33,000 volts.

The grounding type used for voltage levels below 660V is solid grounding.

Low resistance or reactance grounding is applied for voltages between 3.3kV and 11kV.

For voltages of 22kV and above, solid grounding is again used.

Neutral grounding ensures a balanced three-phase supply and simplifies earth fault management.

Proper grounding reduces or eliminates arcing grounds, making systems safer.

A first aid box must be present at every workplace, with its location clearly displayed.

The site owner must provide fire fighting facilities in compliance with safety regulations.

Fire is rapid combustion releasing heat, light, and gases.

Fires can start from electric arcs, sparks, loose connections, and welding.

Fires are classified into Class A, B, C, D, and E based on materials involved.

Methods include cooling, ventilation, smothering, and using water.

Common media include water, CO2, foam, dry chemicals, and Halon.

The required ground clearance for conductors not exceeding 11 kV is 2.75 metres.

The minimum sectional clearance for conductors not exceeding 11 kV is 2.6 metres.

Ground clearance for conductors not exceeding 33 kV is 3.7 metres.

The sectional clearance for conductors not exceeding 33 kV is 2.8 metres.

Baffle walls with a 4 hour fire rating are required between certain apparatus.

Adequate fire protection arrangements must be provided to extinguish fires in apparatus.

Cable trenches in substations must have non-inflammable filling such as sand or pebbles.

All EHV apparatus must be protected against lightning and switching over-voltage.