GB862988A - Improvements relating to electrical measuring instruments - Google Patents

Improvements relating to electrical measuring instruments

Info

Publication number
GB862988A
GB862988A GB3672858A GB3672858A GB862988A GB 862988 A GB862988 A GB 862988A GB 3672858 A GB3672858 A GB 3672858A GB 3672858 A GB3672858 A GB 3672858A GB 862988 A GB862988 A GB 862988A
Authority
GB
United Kingdom
Prior art keywords
contactor
voltmeter
circuit
operated
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB3672858A
Inventor
George Frank Tagg
William Edward Collier
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Evershed and Vignoles Ltd
Original Assignee
Evershed and Vignoles Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Evershed and Vignoles Ltd filed Critical Evershed and Vignoles Ltd
Priority to GB3672858A priority Critical patent/GB862988A/en
Publication of GB862988A publication Critical patent/GB862988A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
    • G01R27/18—Measuring resistance to earth, i.e. line to ground

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

862,988. Measuring instruments. EVERSHED & VIGNOLES Ltd. Nov. 6, 1959 [Nov. 14, 1958], No. 36728/58. Class 37. A device to measure the impedance of the fault path of an A.C. system, by direct connection to the three leads of the system, comprises a contactor operated by a tuning device, whereby the contactor is closed for a short period of time to complete a circuit between the phase and earth conductors through a non-inductive resistor across which is connected a ballistic voltmeter calibrated in ohms. In the embodiment described a test set has terminals P, N, E, Fig. 1, for connection to phase, neutral and earth of the A.C. system to be tested. If correctly connected a lamp 2 lights; if not, the connections are reversed to check that the circuit is live, by operation of a switch, the supply voltage being indicated on meter 4. The coil of a contactor 16 is fed with current controlled by motor-operated cams 14, contacts 20 maintaining the motor in circuit when pushbutton 21 is operated, and contacts 15 closing for about 0.1 second and operating the contactor for that period. A ballistic voltmeter 31 indicates impedance by measuring the voltage across a non-inductive resistance 23. Switches S1, S2, S3 enable the current in one of the voltage coils of the voltmeter to be reversed and restore the pointer to zero.
GB3672858A 1958-11-14 1958-11-14 Improvements relating to electrical measuring instruments Expired GB862988A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3672858A GB862988A (en) 1958-11-14 1958-11-14 Improvements relating to electrical measuring instruments

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3672858A GB862988A (en) 1958-11-14 1958-11-14 Improvements relating to electrical measuring instruments

Publications (1)

Publication Number Publication Date
GB862988A true GB862988A (en) 1961-03-15

Family

ID=10390704

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3672858A Expired GB862988A (en) 1958-11-14 1958-11-14 Improvements relating to electrical measuring instruments

Country Status (1)

Country Link
GB (1) GB862988A (en)

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