DC ground Fault Location

                                                                   GFAL-A    Analyzer Unit
                                                                   GFAL-B    Tracking Unit
                                                                   GFAL-ST    Site Training

Locating DC Ground Faults

Abstract
Ground faults on battery operate DC Multifeeder Distribution System are very difficult to find without proper instrumentation and training.

Samco Engineering has design a new microprocessor control instrument with a single purpose “to analyze and locate even the most
difficult faults on battery operate DC Multifeeder Distribution System”, for the safeguard of the DC system integrity.

The Ground Fault Analyzer and Tracking instrument (GFAL-A/B) make use of a very small interrupted and synchronize DC
signal to analyze and locate DC ground faults on multifeeder distribution system .

    Remark from one of our nuclear customer, "We have a split 250VDC system with high stray capacitance. We have had no
    luck previously locating grounds on the common bus. We have tried the Bender, Biddle, DC Scout and Ground Hog equipment
    with no success. We were able to locate a positive ground on Unit One, and an intermittent common ground on Unit Two in
    about 6 hours using the GFAL-A/B equipment. Prior to this, we were living with the grounds."

GFAL-A and GFAL-B

Link to:


         GFAL -A

GFAL-B

TRAINING CLASS

USER'S MANUAL

Equipment and Method highlights

Ground Fault Analyzer Instrument, Model : GFAL-A

* Performs the interruption functions to locate the DC ground faults up to the point of failure

* Functionally test the DC alarm unit operation

* Test the DC Distribution System for spike faults and AC contamination

* Help to find the value of the fault resistance from each polarity with respect to site ground.

See the User's Manual Seccion 8.0 – GFAL- A, Appendix B.

* Set up the basis for a ground fault predictive maintenance program

Ground Fault Tracking Instrument, Model: GFAL-B

* Will trace and locate the DC ground faults on DC multi-feeder distribution system, up to the point of failure without service
interruption

* Detect and process the signal produce by the interrupter with a magnetic sensor (unique design) that wrap around the conductors.

* Never have to open a circuit or a breaker to troubleshoot a DC distribution system

* Set up the basis for a ground fault predictive maintenance program

Training Lecture "Fundamentals of DC Ground Fault" : GFAL-ST

* "Correct and incorrect" ground fault Indication and Location methods and instruments.

* How to identify and locate DC ground faults on DC multi-feeder distribution systems

    *    At the site, practical applications

    Before you purchase a DC ground fault locator instrument ask some questions

Q1) Is the instrument inject an AC signal to locate DC ground faults?

There are 2 probes on inject AC signal instruments to locate DC ground faults.

One probe inject the signal into the DC Distribution System and the other probe track the signal.

If the inject signal probe has a resistance or impedance that is less than 5 Kohms there is a possibility to trip the unit when using this probe.

If the tracking signal probe is a CT current transformer it will saturate when the probe is installed around cables that carry more than 5 Amps

of DC load current and the instrument will fail to track the ground fault on these cables.

Q2) Is the vendor claims that they can locate 100 Kohm DC ground faults on DC distribution system, please ask the vendor with the details

on the locations where they have located such faults.

Q3) Is DC ground fault locating training available at your site from the vendor?

Partial customers list International customers from:

        *     Plant Bowen 3,540 MW (GA)                                        *    South Korea
        *     Plant Scherer 3,564 MW (GA)                                      *   Saudi Arabia
        *     Ray Olinger Plant 420 MW (TX)                                   *    Pakistan
        *    City of Anaheim (250 KV) Substation (CA)                  *    Taiwan
        *    El Segundo GS 684 MW (CA)
       *    ExxonMobil 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)

Carrying Case
Exterior Dimensions: 13 in. H x 17-1/2 in. W x 13 in. D

                            Contact us at:
            Samco Engineering
            Fountain Valley, CA 92708
            E-mail: samcoeng@aol.com
            Attention: Engineering Department
            Phone: (714) 235 - 5901
            If you have questions about DC ground faults, please give us a call or write to us an e-mail.
                                                                                                                                                                                                2010