OP 016: Electricity Flashcards
What are the two flows of electricity?
Direct current (DC) Alternating current (AC)
AC is generally used - DC for specialist use
What are the two classifications of voltages?
Low voltage
50-1000v
High voltage
1000v plus
What are conductors?
Materials that offer very little resistance to the flow of electric energy - electricity will flow along a conductor
How can an electrical shock occur?
Six answers
Directly touching a live conductor
Indirect contact - touching a conductor that is in contact with a live supply
Bringing equipment into contact with a live conductor
Using extinguishing media that conducts electricity
Ionisation of smoke, conducting electricity
Getting too close to high voltages
What are capacitors?
Electrical components used to retain and store electrical energy for a considerable time after the supply of electricity to them has been shut down
Where are electrical gloves carried? What protection do they offer?
Carried on all front line appliances
Hand protection for voltages up to 3,300v
Electricity Authority Premises include what buildings?
Generating stations
Transformer stations
Sub-stations
What is the incident procedure at an incident involving electricity authority premises?
Five answers
Identify sources of live electricity
Crews should protect the surrounding risks with extinguishing media
Crews should not lift covers, or further expose a pavement level cable system to extinguish the fire
Crews must not pass warning signs or gain access into areas which have warning signs restricting access
If any high voltage equipment is identified as being involved, the relevant authorised person must be requested to attend
What procedure is adopted when rescuing a casualty, where there is a risk of electricity?
Three answers
Prior to attempting rescue or retrieval of the person, the supply must be shut down
If a person is lying on top of a transformer, switch, or anywhere else above ground level, they must not be touched until confirmation is received that it is safe
Any rescue from a tower or pole should be made by personnel with a necessary specialist skill
What is the appropriate ground clearance, to offer adequate protection from overhead lines
5 - 7m without equipment
30m for ground monitor
20m for handheld hose
10m for operational working without a hose
What are cable boxes?
Underground compartments that provide access to underground cables in towns - used for testing, making and breaking connections
What are feeder pillars?
Steel cubicles found in open country districts - used for testing distribution cables and making connections
What is the likely voltage supplied to domestic premises?
240v
What does a firefighters switch do?
Mounted to facade of building - 3m above ground
Switches the current off and shuts down the electrical supply to the entire installation
What hazards are presented when dealing with solar panels?
Four answer
Electricity
Hazardous chemical being released
Weight of solar panels on a weakened roof
Falling objects
