Supply
Domestic Installation
Safety
Measurements
100
A typical power station produces a voltage of 28 kV before it is transmitted along the Transmission lines it goes through a yard transformer, what does this transformer do?
Step up transformer
100
Describe the three wires used in domestic installations and their role.
Red - Active
Black - Neutral
Green/Yellow - Earth
100
Before attempting any electrical work what should you do first?
Turn off the electrical supply at the switch board
100
What are the units in the following formula P = V I
Watts = Volts x Amps
200
What does the electricity need to go through between Electricity Transmssion (330 -500 kV) and the Electrical Distribution lines (230/400V)?
Substation Transformer
200
What are three typical electric circuits in a domentic setting?
Power
Lighting
Appliance
200
Where would you find an Earth Electrode?
In the ground
200
In a circuit a Current meter should be placed in?
Series
300
In a multi storey building each floor needs a ? board.
Distribution board
300
What are 4 main components of a basic circuit?
energy source
protection device
control device
load
300
What are three electrical installation hazards?
Electric shock,
Fire,
Hazardous (explosive) gasses
300
In a circuit a Volt meter should be placed in?
Parallel
400
Name 3 back up suply options
Uninterupted power supply (battery)
Generator
Solar Array
400
Describe the difference between a 230V single phase and a 400V 3 phase socket.
400
What are 4 types of protection devices
Fuse
Circuit breaker
Residual Current Device RCD
Surge Protection Device SPD
400
In a circuit an Ohm meter should be placed in?
Parallel
500
What is the frequency of our electicity suply?
50 Hz
500
A solar array produces which type of current to the inverter?
DC
500
What are the main physiological effects of electric shock on the body (6 items)
muscular contraction
burns
breathing difficulties, asphyxiation
ventricular fibrillation
death
500
What are the correct units and value to 3 significant figures for the following
Current value 0.0000007358
736 nA