Plumbing science Flashcards
What does “v” stand for
Voltage
What does “I” stand for
Current
What does “R” stand for
Resistance
What does “W” stand for
Watts
How much is the domestic voltage
230 volts
How do you work out voltage
V= I x R
What is DC
Direct current
What is AC
Alternating current
Example of DC
Battery
Example of AC
Mains electricity
What does the earth wire do
makes current pass through ground instead of the person
what does the live wire do
carries electricity from power to source
is TNS separate or combined
separate
is TNC separate or combined
combined
what is the purpose of an RCD
protects you from electric shocks and electric fires
where is electricity used in plumbing
pump
showers
thermostats
boilers
cookers
what cant plumbers interfere with?
ring final and lighting circuit
what is a safe voltage
low voltage:
230v single phase AC
110v single phase AC
In a TT where does the earth rod go
it goes down to the ground
what is a step down transformer used for
used to bring voltage down
How many Pascals are equivalent to 1 bar of pressure?
100,000 Pa
What type of heat transfer occurs in solids through direct contact?
Radiation
What is the process of water changing directly from ice to vapor called?
Deposition
What type of corrosion occurs due to high flow rates and turbulence in pipes?
Pitting corrosion
What is the main gas component in natural gas?
Methane
What is the unit of electrical current in the SI system?
Watt
Which type of plastic becomes brittle in freezing temperatures?
Polyethylene
