ABSTRACT
The majority of our local electrical supply is made up of these three phase distribution systems
running in the pavements and roads from the local supply sub-station. To receive a single phase supply
in a house a connection is taken from one of the colour coded phase supplies, balancing the load
across all three phases by alternating the colour to different houses. Most domestic properties only have
single phase supplies because the motors on domestic appliances are small, many below a rating of
1kW and, whilst some more powerful cleaners may be rated up to 1.5kW, this is considered acceptable
for a limited period of use. In large buildings designers will usually provide a three phase supply for
any permanently wired motor over the 1kW rating.
