Plumbing science Flashcards
What is the unit of current
Unit of current is ampene.
What is the voltage for domestic homes
230-240v
What happens when voltage is high
The more voltage there is the more push on the electrons
What is the unit of resistance
Ohms
How to calculate current
Voltage/resistance
How to calculate voltage
Current X resistance
How to calculate resistance
Voltage/current
What does i stand for
Current
What are watts
Unit of power from an appliance
What is direct current
Something that provides electricity directly e.g battery(chemical)
What is AC
Alternative current is where the electricity goes through series of stages to get where it needs to go
what does TN(S) mean
separate
what does TN(C) mean
Combined
what is a TT earthing system
where the metal housing of an electrical system is placed underground.
domestic electrics
pumps
showers
thermostats
plugs/spurs
boilers
cookers
what can a plumber do with electrics
can rewire already made circuits but cannot make their own
what’s the purpose of an RCD
found in modern day consumer units and trip out if they are any earth faults
types of circuit protection
cartridge fuses are the older type of circuit protection and are re-wireable
plug tops have cartridge fuses inside.
requirements for electrical installation
IET on-site guide
approved document part p (building regulations
voltage to be used for safety
low voltage:
-230v single phase AC
-110v single phase AC
extra low voltage for safety:
-24v DC
-18v DC
-12v DC
what is a step down transformer used for
used to bring voltage down
what safety features do MCBs have
trip out if an earth fault happens
why is earthing circuits done
to keep us safe from shock or overloading the circuit
