L safety Flashcards
What are the 6 major causes of accidents?
- Pre- occupation - personal worry, distractions
- Ignorance, lack of skill
- Over familiarity, repetition leads to loss of attention to detail
- Laziness and fatigue
- Physical hazards, oil on deck, unguarded machinery, toxic processes.
- Horseplay, messing around not paying attention to your surroundings.
What are the 3 steps you can take to eliminate the accident problem
- Know the hazard - know the precaution
- Maintain safety discipline
- Develop the habit of noticing potential dangers
What are 3 three basic causes of electric shock?
- Equipment failure (indirect contact)
- Human failure (direct contact)
- combination of equipment failure and human failure
State an example of equipment failure
Break down of insulation causing an appliance to become live.
State some examples of human failure.
- Failure to observe proper safety precautions
- Familiarity
- shoddy work
- standing in damp surroundings
- failure to properly test portable equipment
State 2 examples of combination failure (human and equipment)
- Failure to repair leads when carrying out maintenance routines.
- Use of unproven test equipment
What would these 4 different levels of current do to the human body? 1mA 10mA 20mA 30mA
1mA - Involuntary reaction
2mA - Prevent you releasing your hold
20mA - Physical damage
30mA - Can cause death
What is the resistance of the human body when dry?
What factor can decrease the resistance?
- 1kohm
2. The resistance could be lower if the skin is damp
What is the only safe voltage onboard?
24v DC
State the electric shock procedure.
- Raise the alarm (LVA)
- Isolate person from supply, if possible, e.g. switch off supply, open breakers
- if step 2 is not possible, stand on a dry insulating material and try to push or pull the casualty clear of the contact, using similar insulating material as a lever.
- When the casualty is isolated from the supply, check for a response. Shake the casualty by the shoulder and ask loudly ‘are you alright?’
- Shout for help
- Open and check the airway
- Check for normal breathing.
- If you are qualified you should carry out CPR and keep shouting for assistance until help arrives.
What are the purposes of lock off - tag out? (LOTO)
- Allow maintenance to proceed without hazard to maintainers
- Isolate equipment that is defective and dangerous.
- To prevent selection of modes of equipment which may be dangerous.
- Where supplies have been provided but equipment has yet to be fitted
The LOTO consists of five sections or parts what are they?
- The LOTO index sheet
- The LOTO safety certificate
- LOTO label
- LOTO display board
- The removed equipment
The short term tag-out log is comprised of six parts. What are they?
- Instruction and TEM’S
- Audit records
- Index
- New LOTO certificates
- LOTO safety certificates in force
- Closed LOTO certificates
What are the reasons a Long term LOTO would be required?
- Equipment which is likely to be out of action for a period in excess of six months.
- Equipment which is redundant and guidance is needed for removal.
- When electrical supplies have been fitted for equipment yet to be installed.
- Temporary equipment needed for a specific purpose has been removed.
- Short term LOTO’S that are in excess of 6 months old and have yet to be rectified.
What are the 2 parts that comprise the Long term LOTO?
Part 1 - Long term LOTO index
Part 2- Long term LOTO safety certificate
State the procedure for Isolations
- Obtain permission from senior rate to carry out isolations
- Identify all points of isolation
- Inform users and any one who may be affected by removal of supplies.
- Fill out entry in index sheet and collect next sequential serial number
- Senior rate and person requiring LOTO to complete relevant sections of LOTO safety certificate and sign
- Complete LOTO label parts A, B and C. Then turn off equipment
- Remove fuses and attach part A of LOTO label to empty fuse holder
- Place part B of LOTO label on LOTO board and place part C of LOTO label, with fuses, in box provided.
State the procedure for replacing fuses
- Remove the empty fuse holder from the fuse way
- Using approved GPTME test for voltage across the empty fuse way to ensure the fuse way is dead.
- Use the correctly rated fuse to stop cable burnouts.
- Averting eyes, locate the fuse carrier smartly onto the bus bars.
- Tighten with fuse key whilst holding the fuse carrier firmly in place.
- The person completing the LOTO should have parts A,B and C in their possession for inspection by senior rate.
- Complete section 2A of the LOTO safety certificate.
Where are tantalum capacitors found?
Inside AVR’S on ship.
What is the purpose of a tantalum capacitor?
To store an electrical charge.
What is the hazard of a tantalum capacitor?
What PPE should be used when working on this component?
- Under certain conditions these components can explode spraying adjoining components and personnel with sulfuric acid.
- Face protection
What is the purpose of a selenium rectifier?
To change AC voltage to DC voltage
Where can selenium rectifiers be found?
In winches and capstans
What is the hazard when working with selenium rectifiers?
Toxic substances are released when rectifiers burn out.
What is Penetone TPC used to clean?
Electrical components
What is the shelf life of Penetone TPC?
12 months
What is the flashpoint of Penetone TPC?
53 degrees Celsius
Where is Penetone TPC not used?
HM submarines
State the precautions to be taken when working with Penetone TPC?
- Keep away from naked flames
- Supply and exhaust fans are to be used if available
- It is never to be sprayed directly onto live electrical equipment
- Always wear rubber gloves
Name this symbol.
Class one - theta
What are the 3 categories that radioactive valves are broken down into?
- Class one - theta sign
- Class two - Trefoil symbol and words ‘‘class two’’
- Hazard - Trefoil symbol and word ‘‘caution’’
What items of PPE should be worn in the galley?
- DMS boots
- Overalls or 4’s with sleeves rolled down
- Chef’s hat
Where are galley isolation switches located and what colour are they painted?
Just outside the galley they are painted red.
What is the biggest fire hazard in the galley?
The deep fat fryer due to high oil temperature.
When is the only time you can work on live electrical equipment?
When supervised by an ME senior rate.
What is considered high voltage?
1000v AC or 1500v DC
State the precautions to be taken when working with electrical equipment.
- Don’t take risks.
- Wear rubber gloves if practicable.
- Use insulated tools if practicable.
- Stand on rubber insulating mats. Avoid leaning on adjacent bulkheads or equipment.
- Wear insulating footwear. sea boots and DMS boots contain conducting material and are not electrically safe.
- Be aware of voltages that can be present.
- Do not rely on interlocks or other safety devices.
- Unless essential do not render interlocks or safety devices inoperative.
- Don’t work alone.
- Take particular care that tools do not cause short circuits.
- Work with one hand if possible.
- Check all items of portable equipment have been tested.
State the procedure for proving electrical equipment is dead.
- Isolate and carry out the correct tag-out procedure
- Prove the equipment is dead by using by testing between phases and between phase and earth using an item of GPTME.
- Discharge capacitors in the circuit using GPTME.
- If required, fit shorting straps to prevent capacitors from recharging.
What are the 3 types of hand changeover switch?
- Normal/alternative changeover switch
- Normal/emergency changeover switch
- Normal/alternative/emergency changeover switch
State the 3 High voltage classifications
- HV live
- HV dead
- HV safe
What information does HV live convey?
The ship is either generating HV is capable of generating HV or is connected to an external HV shore supply.
What information does HV dead convey?
The ships is no longer capable of generating, distributing or receiving HV. All sources of HV are disconnected and isolated with circuit main earths applied.
What information does HV safe convey?
Informs personnel that a particular area is safe to enter with all forms of HV power source disconnected and appropriate HV decay periods have elapsed.
Describe a competent person (CP)
a CP has sufficient technical knowledge or experience to enable the person to avoid danger from electrical hazards.
State the documents required to control the HV system.
- Permit to work (PTW)
- Sanction for test (SFT)
- Limitation of access (LOA)
- Switching schedules (SS)
When is an arc flash event most likely to occur?
When breakers are racked in and out and when making or breaking the electrical connections.
What should be considered when there is a risk of an arc flash event?
Use of greater levels of PPE.
State the hazards associated with arc flash.
- Heat: up to 20,000 degrees Celsius
- Plasma discharge: IR radiation
- Light: Very intense blinding light. UV radiation
- Pressure wave: vaporised copper expands up to 67,000 times
- Shrapnel: molten copper, insulation, pieces of switchboard
- Sound: at 2m distance 140 - 160db recorded (permanent hearing damage)
- Smoke: containing poisonous vapours and molten particles.
What are the precautions for working on live electrical equipment?
- Do not take risks.
- Wear rubber gloves.
- Use insulated tools (VDE)
- Take care not to cause short circuits.
- Wear insulating footwear.
- Be aware of voltages that are or can be present.
- Do not rely on interlocks or safety devices.
- Unless essential do not render interlocks or safety devices inoperative.
- Don’t work alone.
- Stand on rubber mats, don’t lean on bulkheads or equipment.
- Work with one hand if possible.
- Check all test equipment is in date.
What does PTW stand for?
Permit to work
what does SFT stand for
Sanction for test.
What does LOA stand for?
Limitation of access
State the procedure for removing fuses.
- Place a finger in the centre of the fuse holder.
- With your free hand, unscrew fuse holder using a fuse key.
- When unscrewed, firmly grasp the fuse holder, turn your head away from the fuse box and remove fuse holder.
- Remove the fuse from the fuse holder. Replace empty fuse holder to maintain the dead front of the panel.
- Repeat for the second and third fuse way.
What does SS stand for?
Switching schedules
