ADC 2, and 3 Doubler, HDU-409 Lists 1 APPENDIX C - GROUND FAULTS, GROUND FAULT DETECTION

LTPH-UM-1234-01 Appendix C - Ground Faults

APPENDIX C - GROUND FAULTS

GROUND FAULT DETECTION

The HDU-409 has Ground Fault Detection (GFD) circuits as described in

R7-1, Section 7.2.1 of GR-1089 CORE, Issue 1, Revision 1, December, 1996.

When used with HiGain line units, ground faults occurring at any point along any span are immediately detected. Ground fault conditions shut the HiGain circuit down. The line unit periodically tries to apply power to the first span to determine whether the fault condition is still present. As long as the condition exists, the power cycling and ground fault protection continues. To discontinue the ground fault protection, locate and repair the fault in the cable.

Circuits containing both the HDU-409 and older doublers without a GFD circuit also support this new ground fault detecting feature, provided the doubler nearest the HLU is an HDU-409.

To operate properly, the ground fault circuit requires that the doubler enclosure ground plane be securely connected to earth ground. Failure to do so can cause false triggering of the GFD circuit.

HDU-409 Lists 1, 2, and 3 April 30, 2003 29