Testing method for a ground fault detector

• US 20090085575A1
• Filed: 09/28/2007
• Published: 04/02/2009
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Lindsey, Robert Wayne, Johnson, Curtis Brian
• Granted Patent: US 7,808,245 B2
• Time in Patent Office: Days
• US Class Current: 324/510
• CPC Class Codes: G01R 31/2839 using signal generators, power supplies or circuit analysers G01R31/2879 takes precedence; multimeters G01R15/12, network analysers G01R27/28
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass

Abstract

A testing system for a ground fault detection system of an electrical system of a machine is disclosed. The testing system has a low voltage power source, the low voltage power source capable of operation that is independent from a high voltage power source of the machine. The testing system also has a variable current source that is permanently connected to a positive voltage bus or to a negative voltage bus of the electrical system of the machine, where the machine operates self-sufficiently. The testing system also has a controller connected to the variable current source. The testing system also has an input device, where the input device is connected to the controller.

Claims

1. A testing system for a ground fault detection system of an electrical system of a machine, comprising:

a low voltage power source, the low voltage power source capable of operation that is independent from a high voltage power source of the machine;

a variable current source that is permanently connected to a positive voltage bus or to a negative voltage bus of the electrical system of the machine, where the machine operates self-sufficiently;

a controller connected to the variable current source; and

an input device, where the input device is connected to the controller.

2. The testing system of claim 1, wherein the variable current source includes a resistor.

3. The testing system of claim 1, wherein the variable current source includes a variable duty cycle switch.

4. The testing system of claim 1, wherein the input device is a button.

5. The testing system of claim 1, wherein the input device is located remotely from the controller and connected to the controller by a data link.

6. The testing system of claim 5, wherein the input device is a service tool.

7. The testing system of claim 1, wherein the input device is a touch screen.

8. The testing system of claim 1, wherein the machine is a vehicle.

9. A method for testing a ground fault detection system of an electrical system of a machine, comprising:

providing a low voltage power source, the low voltage power source capable of operation that is independent from a high voltage power source of the machine;

permanently connecting a variable current source to a positive voltage bus or to a negative voltage bus of the electrical system of the machine, where the machine operates self-sufficiently;

connecting a controller to the variable current source;

connecting an input device to the controller;

inducing an actual leakage current in the machine; and

triggering the ground fault detector system.

10. The method of claim 9, wherein the variable current source includes a resistor.

11. The method of claim 9, wherein the variable current source includes a variable duty cycle switch.

12. The method of claim 9, wherein the input device is a button.

13. The method of claim 9, wherein the input device is located remotely from the controller and connected to the controller by a data link.

14. The method of claim 13, wherein the input device is a service tool.

15. The method of claim 9, wherein the input device is a touch screen.

16. The method of claim 9, wherein the machine is a vehicle.

17. An electrical system of a machine, comprising

an electrical system;

a ground fault detection system for the electrical system; and

a testing system for the ground fault detection system, including;

a low voltage power source, the low voltage power source capable of operation that is independent from a high voltage power source of the machine;

a variable current source that is permanently connected to a positive voltage bus or to a negative voltage bus of the electrical system of the machine, where the machine operates self-sufficiently;

a controller connected to the variable current source; and

an input device, where the input device is connected to the controller.

18. The electrical system of claim 17, wherein the variable current source includes a resistor and a variable duty cycle switch.

19. The electrical system of claim 17, wherein the input device is a button or a touch screen.

20. The electrical system of claim 17, wherein the machine is a vehicle.