|
Anecdotally, I have been told that the reason
each home in the US has its own transformer is due to the problems of
distribution. If the 120 volts was carried distances over power
lines voltage drop would be an issue. By transforming the
high voltage at each home this problem is minimised. My understanding why
Australia adopted the 240/415 volt system on the south/east coast, and a
250/440 volt on the west coast, so we can use a single transformer to
service a whole street of homes. While three phases pass each home,
typically only one of these is brought into the home for a 240 volt 80 amp
single phase service.
Rural
areas use a similar system to the US. Properties may have a SWER
(Single Wire Earth Return) service when provision of a three phase
service is not practical. One 11,000 volt overhead line is brought
into the property and then transformed to 230/400 volts. Farmers
purchase special 400 volt single phase motors for pumping stations,
irrigation etc. http://www.ruralpower.org/
I
raised with the family migrating from America to Australia why they
brought all their appliances with them. They said they are cheaper to buy
in the US, and they would have had to try to sell them for much less and buy
them again here for much more. They felt the shipping charges were
justified. I would not do the same in their situation.
Their two
televisions sets and VCRs are only good for watching the VHS tapes
they brought with them, and not for our PAL broadcasts. Newer Australian
Televisions and VCRs are usually multi-standard and may accept NTSC
(Never Twice Same Colour).
The table
lamps had their 120 volt lamps replaced with the 240 volt of the same
type. The receptacle pins on the plug to were twisted to accept
our polarised outlet configuration. Most light fittings in Australia use
the bayonet cap style, however the Edison screw lamps are readily
available in 240 volt. http://www.clipsal.com.au/
They purchased 240/120 volt step down transformers
for other appliances. The food mixers
motors were noticeable slower with 50/60 Hz
difference.
When their
240 volt clothes drier was first connected to our 240 volt circuit. The light in
the drum was dim and the drum also rotated slowly. The lamp was
rated at 120 volts. I have not been in touch with them for several years,
so I expect when the lamp failed or service was required Maytag Australia would
not have provided support. The unit was also rated at 30 amps which does
not comply with our electrical standards. The maximum single phase load
for any appliance is 20 amps. Greater than that, it must be three
phase to distribute the load evenly across the network.
Australian
Maytag MDE3050 9 kg drier $924.94 US ($1,559.00
AU)
http://www.maytag.com.au/laundry/dryers/mde3050/mde3050.pdf
<<< Note: Millimetre Only Specifications
AU
US Maytag
MDE5500A $660.00 US ($1,112.40 AU)
http://image.maytag.com/products/images/products/dndry2.pdf <<< Note: Inch & Centimetre
Specifications US
These US
appliances are typically larger than what Australians generally purchase.
My 4.5 kg drier is wall mounted above my top loading 6.5 kg washer and plugs
into a standard general purpose 240 volt, 10 amp, 50 Hz receptacle. http://www.fisherpaykel.com/
European
front loaders are becoming popular too.
The aspect of
safety from electrocution is provided by mandatory RCDs ('Residual Core Device'
or 'Safety Switch') on all light and power circuits. http://www.energysafety.sa.gov.au/images/pdfs/Safety_switches.pdf
|
