Protective grounding jumper cable tester and testing method

• US 5,631,570 A
• Filed: 05/09/1995
• Issued: 05/20/1997
• Est. Priority Date: 05/09/1995
• Status: Expired due to Fees

• Current Assignee: Hubbell, Inc.
• Original Assignee: Hubbell, Inc.
• Inventors: King, Clayton C.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): DO, DIEP N
• Application Number:
  US08/437,661
• Time in Patent Office: 742 Days
• Field of Search: 324/713, 324/715, 324/525, 324/522, 324/718, 324/539, 324/541
• US Class Current: 324/718
• CPC Class Codes: G01R 1/04 Housings; Supporting members; Arrangements of terminals
• CPC Class Codes: G01R 27/205 Measuring contact resistance of connections, e.g. of earth connections
• CPC Class Codes: G01R 31/14 Circuits therefor , e.g. for generating test voltages, sensing circuits G01R31/1209 - G01R31/1227 take precedence; for testing switches G01R31/327

Abstract

A protective grounding jumper cable tester basically includes a housing, a direct current power supply, a pair of jumper attachment terminals, a pair of test probe terminals, a current applying circuit connected between the direct current power supply and the pair of jumper attachment terminals for applying a direct current through a jumper cable attached between the jumper attachment terminals, and a resistance sensing circuit connected to the test probe terminals for sensing resistance to the flow of the direct current through the jumper cable by using a pair of test probes connected to the test probe terminals. A protective grounding jumper cable testing method includes connecting a jumper cable that is to be tested between a pair of terminals, applying a direct current to the cable, observing a current sensing meter while adjusting the direct current flowing through the jumper cable, either continuing with testing of the jumper cable if the direct current can be adjusted to a first preselected quantity, retest the jumper cable after inspecting and maintaining it or reject the jumper cable, setting a resistance sensing meter to sense resistance within a first preselected test range, contacting a pair of test probes to the terminals to indicate the resistance of the jumper cable to the direct current, comparing the resistance indicated by the resistance sensing meter with the first preselected test range, and, based on the comparison, either accept the jumper cable, retest the jumper cable after inspecting and maintaining it or reject the jumper cable.

Claims

1. A protective grounding jumper cable tester, comprising:

(a) a housing having a top panel extending thereacross;

(b) a pair of jumper attachment terminals mounted on said top panel of said housing for attachment of a jumper cable therebetween, said jumper attachment terminals including a base member fixedly attached on said housing and a post member having means releasably engageable with complementary engaging means on said base member for temporary attachment of said post member to said base member such that said post member extends outwardly from said top panel of said housing;

(c) a pair of test probe terminals mounted on said top panel of said housing for connection of a pair of test probes thereto;

(d) a current applying circuit disposed in said housing below said top panel and connected to said pair of jumper attachment terminals for applying a direct current through a jumper cable attached between said jumper attachment terminals; and

(e) a resistance sensing circuit disposed in said housing below said top panel and connected to said pair of test probe terminals for sensing resistance of the jumper cable attached between said jumper terminals to the flow of said direct current therethrough by using a pair of test probes connected to said test probe terminals.

2. The tester of claim 1, wherein said current applying circuit includes:

a current sensing meter mounted on said top panel for sensing said direct current applied through the jumper cable and to display the quantity of direct current applied through the jumper cable; and

a rheostat for adjusting said direct current applied through the jumper cable until a preselected quantity is indicated by said current measuring meter, said rheostat having a turning knob disposed above said top panel of said housing operable for adjusting the direct current applied through the jumper cable by turning of said knob.

3. The tester of claim 1, wherein said resistance sensing circuit includes:

a resistance measuring meter for indicating the resistance of the jumper cable to the flow of said direct current therethrough, said resistance measuring meter having a display mounted on said top panel of said housing which provides resistance readings in milliohms; and

a resistance measuring meter range selector switch having a rotatable knob disposed above said top panel of said housing for selecting at least one predetermined resistance test range within which said resistance measuring meter indicates the resistance of the jumper cable to the flow of said direct current therethrough.

4. The tester of claim 3, wherein said resistance measuring meter range selector switch is operable for selecting one of a plurality of different predetermined resistance test ranges.

5. The tester of claim 1, wherein said base member of said jumper attachment terminal is an internally threaded connection block and said post member of said jumper attachment terminal is externally threaded so as to thread into and from said connection block to respectively deploy said post member for use and remove said post member for storage in said housing.

6. A protective grounding jumper cable tester, comprising:

(a) a housing having a top panel extending thereacross;

(b) a power supply disposed within said housing below said top panel for receiving alternating current and producing a direct current output;

(c) a pair of jumper attachment terminals mounted on said top panel of said housing for attachment of a jumper cable therebetween, said jumper attachment terminals including a base member fixedly attached on said housing and a post member having means releasably engageable with complementary engaging means on said base member for temporary attachment of said post member to said base member such that said post member extends outwardly from said top panel of said housing;

(d) a pair of test probe terminals mounted on said top panel of said housing for connection of a pair of test probes thereto;

(e) a current applying circuit in said housing connected between said power supply and said pair of jumper attachment terminals for applying a direct current through a jumper cable attached between said jumper attachment terminals, said current applying circuit including;

(i) a current sensing meter mounted on said top panel for sensing said direct current applied through the jumper cable and to display the quantity of direct current applied through the jumper cable; and

(ii) a rheostat for adjusting said direct current applied through the jumper cable until a preselected quantity is indicated by said current measuring meter, said rheostat having a turning knob disposed above said top panel of said housing operable for adjusting the direct current applied through the jumper cable by turning of said knob; and

(f) a resistance sensing circuit in said housing connected to said pair of test probe terminals for sensing resistance of the jumper cable to the flow of said direct current therethrough by using a pair of test probes connected to said test probe terminals, said resistance sensing circuit including;

(i) a resistance measuring meter for indicating the resistance of the jumper cable to the flow of said direct current therethrough, said resistance measuring meter having a display mounted on said top panel of said housing which provides resistance readings in milliohms; and

(ii) a resistance measuring meter range selector switch having a rotatable knob disposed above said top panel of said housing for selecting at least one predetermined resistance test range within which said resistance measuring meter indicates the resistance of the jumper cable to the flow of said direct current therethrough.

7. The tester of claim 6, wherein said resistance measuring meter range selector switch is operable for selecting one of a plurality of different predetermined resistance test ranges.