This meter was used in the substation at Burrinjuck hydro-electric power station, which is on the Murrumbidgee River near Yass in NSW. It indicated power factor at one of the station's turbo-alternators from the time it was installed, in 1938, until the instrumentation was updated in 2000. It represents efficient power station practice, the challenge of keeping electricity supply and demand in balance, and twentieth century working life in power stations.
Power factor is the ratio of real power (available to the user) to apparent power (supplied by the utility). The optimum power factor of unity is only achieved if load is purely resistive, for instance if the alternator is supplying power only to incandescent lamps. Power factor changes whenever induction motors supplied by the electrical grid are switched on or off; this is because motors need to draw part of the current to create a magnetic field. Likewise, fluorescent lights do not draw power with the same characteristics as the power generated, so switching them on or off changes the power factor. Capacitors, either at the power station or in line with motors on industrial premises, can bring supply and demand back into balance; utilities impose financial penalties on heavy users when their power factor drops, providing them with the incentive to improve power factor.
At its peak, the workforce at Burrinjuck Power Station numbered about 30. Shifts were organised so that groups of meters set in control panels were under continuous observation while the alternators were working. Workers entered meter readings in a log book at regular intervals.
If the power factor moved below 0.8, the operator would switch part of the load to another alternator or switch the output to a bank of capacitors. This would bring the factor closer to 1, where efficiency is best. This is critical, not just to maintain economy of operation, but because an alternator could overheat and parts could melt if its efficiency dropped too far; efficiency is a measure of the proportion of energy input that is converted to electrical energy rather than to heat.
Since 2000, Burrinjuck power station has been maintained by a staff of one, and power factor and other variables are displayed on a small computer screen. The measurement is still carried out in the same way, but the interface with the operator is very different. The same trend has occurred in thermal power stations, so that the whole industry has shed very large numbers of staff in recent years.
Debbie Rudder, Curator, 2006
The meter was made by Metropolitan Vickers at Manchester in the UK. The Metropolitan Vickers Electrical Company was formed in 1919 when the Metropolitan Carriage, Wagon and Finance Company bought out the American owners of British Westinghouse, which was then acquired by Vickers Limited. The firm merged with British Thomson Houston to form Associated Electrical Industries Limited in 1929, but both firms retained their separate identities until 1960. Throughout its existence, Metropolitan Vickers exported electrical equipment to Australia, particularly for use in the railway and power industries.
The meter was used in the substation at Burrinjuck number 2 hydro-electric power station near Yass in NSW to indicate the power factor at the 5MW number 4 turbo-alternator. It was installed when the power station was built in 1938 and removed in 2000. The donor was the engineer in charge of the Burrinjuck redevelopment project; he removed the then obsolete meter and kept it in his care until he retired from Pacific Power and offered it to the Museum.
This text content licensed under 
This text content licensed under