Incidents involving electricity PN796 Flashcards
the minimum safe approaching distance when using monitors (ground or aerial) is?
30m corridor
once Wind Turbine power isolation has been requested and blades “locked off”, does that remove residual electrical charge?
no - locking blades does not remove elec. risk
ICs must consider the effect of isolating power supplies in which three types of premises?
a) where there are machine processes
b) the absence of electrical supplies will affect occupants safety or welfare
c) there may be an adverse impact on business continuity
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?
5m
when can electrical gloves be used?
when voltage is known to be less than 3300v
what is the initial cordon for a turbine incident
300m
Ground and aerial appliances should not be used within how many meters from a live conductor?
30m
Electrical hazards in a fire situation
4 listed
Large quantities of fuel may be stored (within power stations)
Oil filled transformers
Insulating materials
Gearbox oil
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
the minimum safe approaching distance in dense smoke or flames for approaching the conductor is?
20 corridor
what is the usual cordon recommended as a starting point for wind turbine fires?
300m
what two things will an electrical premises (or equipment concerned with generation & supply of electricity) have to restrict access?
- secure doors to switch rooms etc
2. fencing around installations
minimum safe distance when using ground monitor on overhead cables
30m
which firefighting media does not damage electrical equipment?
CO2
vapourising liquids
the minimum safe approaching distance for rescues is?
5m
On arrival to incidents involving electricity actions (general)?
locate responsible person
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
LFB gloves offer protection up to what voltage?
3300v
minimum safe distance on overhead cables - using ladders/aerial appliances
10m (20m in training)
Insulating materials at incidents involving electricty?
3 listed
PVC - toxic smoke
PCB (Polychlorinated Biphenyls) - insulating liquid (not always labelled)
SF6 (Sulphur Hexafluride) - insulating gas
when should pavement covers be lifted?
NEVER! unless authorised person has confirmed it has been discharged
On arrival at overhead cables?
request urgent attendance of National Grid
what is classed as low voltage?
less than 1000AC or 1500DC
What is high voltage?
greater than 1000volts ac (or 1500volts DC)
FFs should not place themselves in a “corridor” how far either side if a overhead power line?
10m
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 is low voltage?
less than 1000volts ac (or 1500 volts DC)
What is UPS?
UPS is a Uninterruptible Power Supply (e.g battery banks)
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
On arrival of Fire and Explosions in pavement level ducting
3 listed
immediate attendance of authorized person.
cordon
do not touch
What will National Grid pylons and energy operators premises have?
unique markings/ identification plates this information must be included in any message
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
the minimum safe approaching distance for ladders or aerials without hose is?
10m (20 in training)
Once current is switched of to high or low voltage installations is it rendered entirely safe?
No - residual charge of electricity may be present in apparatus
- residual charge needs to be made safe by authorized person
minimum safe distance - In dense smoke or flames approaching conductor
10m
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)
On arrival of Wind Turbines?
request isolation of any power supplies to the wind turbine and confirm that the blades have been “locked out”
when can crews pass electrical warning signs or gain access into areas which have warning signs?
when authorised person is in attendance
when the IC requests attendance of the authorised person, what else must be included in the message?
a) information from ID plates and signs
b) RVP or access restrictions as necessary
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?
4hrs
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
ground and aerial appliance monitors should not be use within what distance of a live conductor?
30m
at a premises where a substation has been provided within a building, the transformer chamber / sub station will be situated against an outer wall. How much fire resistance, within the walls and floors separating it from the rest of the building?
4 hours
name the 5 specific hazards associated with electricity
electric shock fire explosion hazardous gases and liquids trip hazards
What will supply or distribution facility display?
a unique identifier on a conspicuous indicator plate
On arrival at a Substation?
request urgent attendance of authorized person
minimum safe distance when using hand held jets on overhead cables
20m
what is classed at high voltage?
over 1000 AC or 1500 DC
