Flashcards in Incidents involving electricity PN796 Deck (29)
Rescues - When carrying out a rescue in the vicinity of overhead lines, substations and other electrical equipment belonging to the electricity supply industry what is the minimum safe approach distance
minimum safe distance on overhead cables - using ladders/aerial appliances
10m (20m in training)
minimum safe distance - In dense smoke or flames approaching conductor
minimum safe distance when using hand held jets on overhead cables
minimum safe distance when using ground monitor on overhead cables
At premises where a sub station has been provided within a building the transformer chamber/sub station will be situated against an outer wall. The wall and floors separating it from the remainder of the building will have at lease how many hours standard of fire resistance?
What will supply or distribution facility display?
a unique identifier on a conspicuous indicator plate
Can crews lift covers to further expose a pavement level cable system to extinguish fire
No - unless the authorized person has confirmed that power has been isolated and residual current has been discharged
Once current is switched of to high or low voltage installations is it render safe
No - residual charge of electricity may be present in apparatus - residual charge needs to be made safe by authorized person
Electrical hazards in a fire situation
Large quantities of fuelmay be stored (within power stations)
Oil filled transformers
Insulating materials at incidents involving electricty?
PVC - toxic smoke
PCB (Polychlorinated Biphenyls) - insulating liquid (not always labelled)
SF6 (Sulphur Hexafluride) - insulating gas
On arrival to incidents involving electricity actions (general)?
locate responsible person
On arrival at overhead cables?
request urgent attendance of National Grid
On arrival at a Substation?
request urgent attendance of authorized person
On arrival of Fire and Explosions in pavement level ducting
immediate attendance of authorized person. cordon & do not touch
On arrival of Wind Turbines?
request isolation of any power supplies to the wind turbine and confirm that the blades have been "locked out"
Ops procedure for pavement level cable systems fires?
Under no circumstances should crews seek to lift covers or further expose a pavement level cable system to extinguish the fire unless the authorized person has confirmed power isolated and residual current discharged
What will National Grid pylons and energy operators premises have?
unique markings/ identification plates this information must be included in any message
If there is the possibility of high voltage present can f/f enter the risk area?
No - if any possibility at all no entry to risk area is to be made
If it is confirmed the residual electrical supply is of low voltage can action be taken?
Yes providing appropriate controls are put in place e.g electrical gloves
Ground and aerial appliances should not be used within how many meters from a live conductor?
what is the distance (corridor) for firefighters and equipment when dealing with overhead power lines
10m either side of the overhead cable (measured along the ground)
what is the usual cordon recommended as a starting point for wind turbine fires?
Can rescue be made from electrical apparatus?
supply must be shut down! if the voltage is known to be 3300v or less LFB electrical gloves will provide adequate protection
when can electrical gloves be used?
when voltage is known to be less than 3300v
A person is seen to be lying on top of a transformer, switch, or anywhere else above ground level can we attempt a rescue?
No - they must not be touched until word is received from an authorized person of electricity authority that it is safe for rescue work to be carried out
What is high voltage?
greater than 1000volts ac (or 1500volts DC)
What is low voltage?
less than 1000volts ac (or 1500 volts DC)