Incidents Involving Electricity: Policy 769 28.03.17 Flashcards
Electricity company premise include?
- Power stations.
- Sub stations.
- Distribution cables/equipment.
- Fenced enclosures.
- Wind turbines.
What kind of fire resistance do the walls and floors of a sub station have?
At least 4 hours.
What will every supply or distribution facility have?
A unique identifier located on a conspicuous indicator plate.
ALL premises or equipment that is concerned with the generation and supply of electricity will have what access restrictions?
- Secured doors to switch rooms or transformer installations.
- Fencing around installations or equipment placed out of reach (high or below ground).
At incidents involving smoke issuing/fire in pavement can crews lift covers and further expose affected area and extinguish any fire?
No. Not unless power confirmed off and any residual current has been discharged and this is confirmed by authorised person.
How may electric shock occur at an incident involving electricity?
- Touching live or damaged electrical apparatus, equipment and appliances.
- Overloading supply or illegal activity.
- Direct application of water or foam.
- Standing in water, oil or fluid exposed to live electricity.
- Ionisation or air causing arcing.
- Residual charge after isolation.
- Theft or gear integral to electrical safety now making item assumed safe now live.
During incidents involving electricity what hazards should you consider in a fire situation?
- Large quantities of fuel may be stored including hazardous substances such as methanol, propane, methane and oxygen.
- Oil filled transformers and switch gear can fail without warning and pose risk of explosion.
- Insulating materials, oil and plastics may create a large amount of toxic smoke.
- gearbox oils may present in large quantities in nacelle if turbine. These are generally combustible and cause burning oil to drop inside or outside tower.
Other than fire and electric shock what other hazards do FFs need to be aware of at incidents involving electricity?
- Explosion (under pavement and failure of transformers etc)
- Hazardous gases/liquid (FI, battery acid)
- Trip hazards (covers, great and oil, sumps and wells)
- Insulating materials (PVC, PCBs, SF6).
Who should you request attendance/do on arrival at incidents involving (a) Power stations (b) overhead cables and pylons (c) Substations (d) pavement incidents (e) wind turbine sites?
(A) on site authorised person. Refer to on site policy/planning.
(B) National grid.
(C) Elec authority (eg London Power Networks)
(D) Elec authority
(E) Onsite personnel. Isolate power and confirm blades are locked out.
What surroundings should be taken into account by an IC at a pavement ducting incident?
- other nearby inspection covers.
- impact of explosion on nearby buildings eg glass fronted.
- cover fire risks.
What should an IC include on an assistance message to the relevant authorised person?
- Info from identification signs and plates.
- RVPs/access.
- Any known apparatus involved.
The IC must consider the effects of isolating power in premises where:
- there are machine processes.
- it will affect residents safety.
- adverse impact on business continuity.
Can ladders and aerial appliances be used at external substations?
Only after confirmation from authorised person that it is safe to do so.
As well as safe distances what must an IC also use Arab incident involving overhead cables?
Safety officers and Comms is constantly maintained to inform of proximity.
Recommended Safety cordon for a wind turbine?
300m but risk assessed.
What is UPS and why does an IC need to be aware of this?
Uninterruptible Power supplies. Back up power in case supply is not constant. If involved will need to be isolated. Could be generators powered by fossil fuels and or battery banks.
What are the hazards of battery bank and what control measures are suitable?
They will remain live after circuits are isolated until their power has drained. If damaged their contents could pose a hazmat risk.
Unless stated they are low voltage so LFB elec gloves are adequate protection from shock.
Can you attempt rescue if a casualty in contact with electrical apparatus?
No not until supply shut down. If known to be less than 3300v then LFB elec gloves are adequate protection.
What is deemed high voltage?
Greater than 1000 volts ac or 1500 volts dc.
What is the difference between the authorised person and responsible person?
Authorised is rep of Elec authority and concerned with isolation etc and responsible has control of the premises.
Safe distance from overhead cable, substations and and associated apparatus for rescue?
5m
Safe distance from overhead cables, substations and associated apparatus for ladders/aerials?
10m or 20m during training.
Safe distance from overhead cables and associated apparatus in dense smoke and flame?
10m corridor
Safe distance from overhead cables and associated apparatus when using handheld jets?
20m corridor
Safe distance from overhead cables and associated apparatus when using monitors (ground of aerial)?
30m corridor
