Specimen of underground electric power cable, 3 conductors, 4 mil
date: label: Date made
content: 1900
notes: label: Description (Brief)
content: Underground Electric Cable, 3 power conductors of 7 strands copper wire each separately insulated with heavy covering of rubber bedded in jute and covered with outside rubber insulation and lead. Made by the Safety Insulated Wire and Cable Co. of New York, and put in service in Wisconsin in November 1900 by the St. Croix Power Co. to carry a current of 25,000 volts.
label: Description (Brief)
content: According to Ira Henry of Safety Insulated, writing in 1901: "I find in looking over the data that the cable of which you have a sample is composed of a strand of 7 wires each 98 mils in diameter, best soft Lake copper evenly tinned and equal in conductivity to No. 2 Brown & Sharpe Gauge. Each conductor is then insulated with a seamless cover of best Para rubber having a wall of 7/32 of an inch in thickness. The three conductors are then laid up spirally with jute, and covered with a seamless rubber jacket 5/32 of an inch in thickness. Over this is placed a serving of tape which is then protected by a lead sheathing 1/8 of an inch in thickness. This cable was tested in our laboratory with an alternating current applied between the conductors and the lead sheath to a maximum pressure of 56,000 volts without breaking down. The average insulation resistance is 2,000 megohms per mile. The average electro static capacity is .450."
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from the St. Paul Gas Light Co.
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: EM.209181
label: catalog number
content: 209181
label: accession number
content: 37405
objectType: label: Object Name
content: Cable
label: Object Name
content: cable sample
label: Other Terms
content: Cable; Cables and Wires; Power
physicalDescription: label: Measurements
content: overall: 4 in x 2 1/4 in; x 10.16 cm x 5.715 cm