Electrical Safety Flashcards
What is one way to prevent electrical shock?
- All exposed live parts covered or insulated
- All circuits permanently identified
- Work with a partner if equipment is live
- Assume every circuit is live
- Shut off power when examining or repairing equipment
- Avoid wearing conductive jewelry
- Check completely before first start
- Open and close switches firmly
- Use approved gloves and rubber mats/shields
- Use only dry chemical or multipurpose fire extinguisher
- Stand to the side of large switch gear
- Use fiberglass or wooden ladders.
What are the typical negative effects of an Arc Flash?
- Burns
- Fire
- Flying objects (molten metal)
- Blast pressure of 9700 kg/m2
- Sound levels of 165 dB
- Heat upwards of 20000°C.
How many hazard risk levels are there for electrical tasks?
Five levels.
What are the “set” and “pitch” of a hacksaw?
- Set: Amount of teeth from side to side; related to the thickness of the cut produced.
- Pitch: Amount of teeth per inch
What are the five steps of a safe work practice, as outlined in CSA Z462?
- Employer electrical safety practices
- Engineering study with arc flash hazard analysis
- Conduct regular safety training
- Ensure adequate supply of PPE
- Maintain electrical distribution system
What is the primary energy which causes an explosion during an arc flash?
The vaporization of solid material due to the intense heat.
In case of an electric shock, there are five steps to emergency action; what are these five steps?
- Remove the victim
- Prevent further injury
- Send for qualified help
- Eliminate the danger
- Report the accident
There are six basic steps to locking out equipment; what are these steps?
- Inform everyone significant
- Shut down by normal procedure
- Operate energy isolating device
- Install lock and tag
- Confirm equipment is isolated
- Check to make sure it is safe to re energize after work is complete
What are the three boundaries of approach for an arc flash hazard?
- Limited
- Restricted
- Prohibited
What determines an arc flash protection boundary?
1.2 cal/cm2 of incident energy. Which is when PPE is required to prevent a second degree burn.
Arc flash is responsible for approximately “___”% of electrical deaths in the workplace.
50%
What are taps and dies used for?
- Taps are used to make female threads.
- Dies are used to make male threads.
What is arc duration?
The total time it takes a protective device to interrupt the fault current.
Does a taper tap make straight threads?
Yes, straight female threads.
What is an electricians most useful tool.
Linesman’s pliers.
