Domestic electricity Flashcards
Reviss
What does an MCB do
Electromagnet breaks when current is too high
What is an MCB
Miniature circuit breaker
What is an RCCB
Residual circuit breakers
What does an RCCB do
compares the current in the live wire to the current in the neutral wire, if the live current is different from neutral the RCCB opens switch and breaks circut
Who does RCCB protect
People
What does MCB protect
The appliances and avoids fires and ensures safety of circuit
Advantage of RCCB
Has a reset button, much faster than a normal fuse
Advantage of MCB
Better than fuse as it can be reset but fuse has to be completely replaces
What are the currents for plugs
3A, 5A, 13A
D.C
Direct current
doesn’t change value
one direction
A.C
Alternating current
value changes
changes direction 50 times a second
has a frequency of 50 Hertz
What is the fuse job
Safely designed to stop too much current flowing
How does a fuse work
If too much current flows in a circuit, fuse wire gets hot , melts and breaks the circuit. Stops current flow and makes circuit safe.
In a ring mains circuit, how many wires and what are the wires called
-live wire
- neutral wire
-earth wire
Ring mains
The plugs are all arranged in one loop , it is protected by a MCB the benefits are the sockets can be placed anywhere.
how do you know if you have chose the right fuse?
the fuse should have a current just above it
eg 4A use a 5A fuse
Live wire function
carries the current in
neutral wire function
carries the current away
earth wire function
safety wire and stops electric shock
how does the earth wire work?
provides safe route for electrical current to flow if there is a fault that causes the live wire to touch metal case a large current will flow along the earth wire preventing electric shock
consumer unit (fuse box)
contains circuit breakers and fuses that all electrics are connected to
