Element 5 - Electrical Safety

Question 1

What is current?

Answer 1

Flow of electricity through conductors measured in amps

Question 2

What is voltage?

Answer 2

The driving force that pushes an electrical current through a circuit measured in volts

Question 3

What is resistance?

Answer 3

Current flow is affected by impedance, resistance is measured in ohms

Question 4

What is the triangle sum for electricity?

Answer 4

Volts (v) = current (amps) x resistance (ohms)

V = I x R

Question 5

What are the mains risks of electricity?

Answer 5

Electric shock 
Electric burns 
Electric fires 
Electric arcing 
Secondary hazards such as falls

Question 6

Give 4 injuries from electric shock

Answer 6

Muscle spasms
Burns
Cardiac arrest
Loss of consciousness

Question 7

Give 6 Factors that will influence the severity of an electric shock?

Answer 7

Current 
Duriation of contact 
Path through the body 
Nature of contact 
The environment - wet 
Resistance - clothing worn

Question 8

Give 8 control measures of working with electricity?

Answer 8

Protection of conductors - insulate them
Strength and capability of equipment 
Fuses 
Earthibg 
Isolation and lock off 
Double insulation 
Rcd's 
Competent persons 
Safe systems of work

Question 9

Give 4 ways to minimise the risks when working near overhead cables?

Answer 9

Bunting
Make lines dead
Goalposts
Ground level barriers 6m away from lines
Restrict the reach of the lifting equipment

Question 10

Give 4 ways to minimise the risks when working near underground cables?

Answer 10

Cat scan 
Survey 
Plans 
Hand dig with rubber shovels 
Tape piping 
Support cabling 
Isolate the supply

Question 11

What are the 3 elements of pat testing

Answer 11

User checks
Formal visual inspection
Combined inspection and tests