DC Ground Fault Location
                                            Tracking Unit

           Locator unit, GFAL-B
           
  Introduction

    Samco Engineers design a method (GFAL) and instrument (GFAL-A, GFAL-B)
    to analyze and locate DC ground faults on ungrounded DC battery multi-feeder
    distribution systems. 
    The design was very successful, and today we have is an  instrument capable
    of quickly locating these DC ground faults. 

    Abstract

    The GFAL-A/B instrument has been used for many years in stations,
    substations and nuclear power plants to troubleshoot their DC systems
    ground faults and has been effective in locating the faults without ever
    causing a system trip, or taking a unit off-line.
 

    GFAL-B (tracking unit)

    *      Does not require system interruption
    *      Locate DC ground faults with this hand held portable instrument 
    *      Protect your sensitive electronic equipment 
    *      Unique design reduces system outages 
    *      No need to be connected to the AC main to operate
    *     New: Will detect how much fault exist on each branch   

                                                        GFAL-B


                                                                         OVERVIEW

        Traditional methods of indicating DC ground faults are ineffective when two or more faults are in opposite polarities of the DC multi-feeder
        distribution system.

        Samco engineering has created a new method that quickly will identify these faults on each polarity.

        However once a fault has been identified, the fault must be located in order to be corrected.

        Locating a DC ground fault is currently done in two ways.  The first method consists of opening circuit breakers or disconnecting branches
        and interrupting the system until the fault is cleared, a procedure that is time consuming inaccurate and costly, since it requires shutting down the system..

        The second method to locate DC ground fault injects an AC signal with respect to ground into the DC system.  This process can inadvertently
        damage sensitive electronic equipment or cause expensive nuisance trips.

                                                                  THE GFAL EXPLAINED

        The GFAL-A (interrupter) and  GFAL-B (receiver) are battery operated portable instruments that utilizes a DC tracking signal create by the
        interrupter and the fault resistance.

        A Hall Effect magnetic Sensor Assembly is attach to the GFAL-B that wrap around  the conductors to track the tracking signal.

        There are three mayor components that make the GFAL-A/B instrument.

               Case
  Item 1)  The interrupter unit GFAL-A creates a DC interrupted tracking signal 
               utilizing the fault resistance. 

  Item 2)  The hand held unit GFAL-B house the microprocessor and the 
                analog electronics and track the tracking signal. 

  Item 3)  The magnetic sensor assembly (MSA) detect the magnetic field 
                produce by the tracking signal. 
               This MSA wrap around the conductors under test and is connected 
                to the GFAL-B.

                                Carrying Case

       PROVEN RESULTS

        Below is a partial list of users that have benefited from the innovative method implemented by the GFAL-A/B

            
              Plant Bowen 3,540 MW (GA)
              Plant Scherer 3,564 MW (GA)
              Ray Olinger Plant  420 MW (TX)
              City of Anaheim (250 KV) Substation (CA)
               El Segundo GS 684 MW (CA)
              Exxon Mobil Refinery (CA)
              Callaway Nuclear Plant (MO)    
              Comanche Peak Nuclear Plant (TX)
              Wolf Creek Nuclear Plant (KS)
               Brunswick Nuclear Plant (NC)
              Diablo Canyon Nuclear Plant (CA)
               Palo Verde Nuclear Plant (AZ)
              Hatch Nuclear Plant (GA)
              Vogtle Nuclear Plant (GA)
              Three Mile Island Nuclear Plant (PA
              Bonneville Power Administration, Gov (OR)
              Arnold Airforce Base, Gov (TN)
              Paradise Power Plant,TVA Gov (KY)

       Minimum specification of the GFAL-B

        Sensitivity:  ............................................3mA, will locate up to 40,000 Ohms fault in a 130VDC distribution system. 
        Operating DC range...............................12 to 270 VDC 
        Impedance range....................................No load to the DC distribution system
        Accuracy ...............................................From 1 to +/- 20%, depends on the MSA installation
        Environmental........................................30 to 125 Degrees F 
        Power adapter input ............................. 12-18 VDC (center positive polarity}
        Internal battery operation....................... 24 hr (rechargeable) 
        Display...................................................One alphanumeric 16 characters 
        Dimensions ............................................10” x 11” x 4.3” 
        Weight ...................................................4 Lb. 
        Case (2 colors) .....................................Gray and yellow 
        Warranty...............................................1 year parts and labor


       If you need more information, please contact us at:
                                     Samco Engineering
                                     Fountain Valley, CA 92708
                                     Phone: (714) - 235 - 5901
                                     E-mail: samcoeng@aol.com                                                                                                               Return to Home page
                                2017