BOT Unit Meter [Seimens]

Seimans Brothers Dynamoworks Limited, Manufacturer

Circa 1920
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Maker and Role
Seimans Brothers Dynamoworks Limited, Manufacturer
Production Date
Circa 1920
A Type G.8. ampere meter made of cast iron with a square window and the makers plate on the face. B.O.T. meters were used in sub-stations and were also supplied to the Auckland Tramways. 460 volt +/-, 2x500 In late 19th century Britain a unit of electric energy (now known as a Kilowatt hour) was known as a Board of Trade unit or B.T.U. (or earlier B.O.T. unit). The Board of Trade unit of energy for commercial electric lighting was equal to 1000 watt hours. A 20-unit dynamo is one that gives a current of 20,000 volt-amperes, and therefore gives 20 units per hour.
Processed Material/Metal
Processed Material/Glass
Signature/Marks and Type
B.O.T. Units / Watthour Meter Type G8 / For Continuous Current / No. 966112 / 460 Volts ± 2x500 Amps / 1 B.O.T. Unit = 17.86 Revs of Disc / Siemens-Bros-DynamoWorks Limited London / Made by Siemens-Schuckert Werke Germany. Maker's Plate
Accession No
Credit Line
Seimans Brothers Dynamoworks Limited. Circa 1920. BOT Unit Meter [Seimens], 2011.144. The Museum of Transport and Technology (MOTAT).

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