Artifacts part 3
PRINTING DEMAND METER
Printing demand meter (maximum demand printometer) manufactured in USA by General Electric. Circa 1950.
Type PD-5. Serial number 626103. Operating voltage 18V DC.
Enclosed in a cast-iron case with approximate overall dimensions 300mm wide x 330 high x 205mm deep.
The instrument is currently on display at Palmiet Power Station.
TIME LAG RELAY
An electromechanical constant definite time delay relay made in the United Kingdom by Reyrolle.
Time delay is fixed at 5 seconds. Operating voltage is 15V DC.
Type T.D. Article number 415C98. Serial number BQTTD67.
Enclosed in a cast-iron case with approximate overall dimensions 240mm wide x 180 high x 110mm deep.
The instrument is currently on display at Palmiet Power Station.
SINGLE ELEMENT INSTANTANEOUS RELAY
A single pole, attracted armature, non-directional, instantaneous over current relay. Manufacturer was possibly the Victoria Falls and Transvaal Power Company Limited or Escom.
Enclosed in a cast-iron case with approximate overall dimensions 230mm diameter x 100mm deep.
The instrument is currently on display at Palmiet Power Station.
THREE ELEMENT INSTANTANEOUS RELAY
A three pole, balanced beam, non-directional, instantaneous over current relay. Manufacturer was possibly the Victoria Falls and Transvaal Power Company Limited or Escom.
Type instantaneous over current. Serial number 8995. Setting range 2 – 10A 50Hz. Trip circuit 24V DC.
Enclosed in a cast-iron case with approximate overall dimensions 370mm x 200mm high x 110msm deep.
The instrument is currently on display at Palmiet Power Station
THEODOLITE
A “Rand Model” theodolite used in the United Kingdom by Cooke Troughton and Simms specially for use in the mining industry. Circa 1925.
It was manufactured to a 1913 patent, and was used by the Victoria Falls and Transvaal Power Company Limited from 1925 to 1940.
The instrument is currently on display at Palmiet Power Station.
TALLY CHAIN
A survey tally chain used by surveyors at the beginning of the twentieth century to measure surface areas.
It is 100 Cape feet (103,3 imperial feet) in length.
The instrument is currently on display at Palmiet Power Station.
TIME LAG RELAY
An electromechanical definite time delay relay, made in the United Kingdom by Metropolitan Vickers. Circa 1950.
Type AKA. Serial number 788073.
Time delay range 0 – 5 seconds. Operating voltage 110V DC. Hand reset flag indicator.
Enclosed in a cast-iron case with approximate overall dimensions 185mm x 220mm high x 120mm deep.
The instrument is currently on display at Palmiet Power Station.
UNIVERSAL POTENTIOMETER
A potentiometer is used to measure alternating and direct current. It was made in the United Kingdom by H. Tinsley and Company. Circa 1930.
Serial number 1278.
Approximate overall dimensions 850mm long x 420mm wide x 90mm high.
The instrument is currently on display at Palmiet Power Station.
PROPORTIONAL DIVIDERS
An instrument used by draughtspersons for enlarging or reducing the length of lines without use of scales for measurement. Circa 1950. This was used extensively for indicating cadastral boundaries on aerial photographs for the purpose of route planning.
The length of both legs of this particular instrument is 180mm.
The instrument is currently on display at Palmiet Power Station.
PLANIMETER
The planimeter is an instrument used for calculating the area of irregular figures. Circa 1940.
This instrument was used by the Victoria Falls and Transvaal Power Company Limited Company Limited (VFP).
The approximate length of both legs of the instrument is 380mm.
The instrument is currently on display at Palmiet Power Station.
PANTOGRAPH
The pantograph is a precision instrument used for the reduction or enlargements of maps. Circa 1940.
It is based on a parallelogram joined at all four corners, and secured at the prolongation of one side. It was used extensively in drawing offices in the early years of the twentieth century. It has been replaced by photographic methods.
The two long sides of this instrument measure approximately 620mm. The two shorter sides measure approximately 300mm.
The instrument is currently on display at Palmiet Power Station.
CURRENT TRANSFORMER
A dry type switchboard current transformer made in the United kingdom by Switchgear and Equipment Company Limited.
Reference number W.O. 88T/1. Ratio 15/5. 50Hz. 15VA maximum. Class C. Maximum voltage 11 000V.
Approximate overall dimensions 150mm wide x 200mm high x 100mm deep.
The instrument is currently on display at Palmiet Power Station.
CURRENT TRANSFORMER
A through type portable current transformer manufactured in the United Kingdom by Ferranti Company Limited.
Reference number 219095. Ratio 800/5. 50Hz. 7,5VA. Class AL. Tested at 2000V.
It is labelled “VF & TP Co. Ltd. Test Dept.”
Enclosed in a wooden case with approximate overall dimensions 200mm wide x 200mm high x 140mm deep.
The instrument is currently on display at Palmiet Power Station.
CURRENT TRANSFORMER
A through type portable current transformer manufactured in the United Kingdom by English Electric Company Limited.
Reference number PPS 29645. Ratio 500/5. 26 – 100Hz. 15VA. Maximum voltage 6600V.
Approximate overall dimensions 320mm wide x 130mm high.
The instrument is currently on display at Palmiet Power Station.
