* Outline of a DC multi-feeder distribution systems
* 125 VDC and 250 VDC multi-feeder distribution systems
* DC multi-feeder systems, load current and fault current path
* Site DC ground fault indicator circuits and DC alarms
* Traditional methods to indicate DC ground faults
* Voltage
imbalance as an indication method to show DC ground faults
AM break
*
Single and multiple ground faults and their display
characteristics
* "Blind spot" of the DC voltage imbalance method to indicate ground faults
* Finding the value of the ground fault from each polarity with respect to site ground
Noon break
*
Review early material, Q&A
* Non contact probe to measure DC milliamps
* Stray capacitance in DC multi-feeder distribution system
*
Magnetics and electromagnetics interferences on field test
equipment
probes
utilize to locate DC ground faults
* Locating DC ground faults, generic procedure
* Theory of AC injection ground fault locator instruments
* New method and instrument, the GFAL-A/B to analyze and locate DC ground faults
*
Locating DC ground fault by the DC tracking current
method in
125 and 250 VDC multi-feeder distribution system
Afternoon break
* Portable Ground Fault Locator instrument GFAL-A/B block diagram
* GFAL-A/B classroom hands on training with a test "jig"
* Utilizing an external power source to troubleshoot de-energize circuits
* Follow the tracking signal inside magnetic and non-magnetic conduit
___________________________________
Field Test Outline
AM (second day)
* Review material from previous day, Q&A
* Set-up the classroom testing "jig" and test equipment
* Review test procedures for a classroom testing
* Student
will perform classroom test with the GFAL-A/B
AM break
*
Review test procedures for field test (or lab test)
NOTE:
A pre-arrange test location
or lab area have to be available at the site
for completing
the field test procedure.
If a test location or such area is not available the classroom
equipment
will be used for this portion of the class
* Transport the GFAL-A/B instrument to a site to perform the field-testing
* Scope of field test (review all safety guidelines first)
* Students will install the GFAL-A (Analyzer/Interrupter) on the DC distribution system
* GFAL-A field data interpretation
* Students will operate the GFAL-B (Detector/Display) Unit and give the field data interpretation
Noon break
*
Locating DC ground faults at the site.
Students will operate the GFAL-A/B Unit
on the
DC distribution system
*
Install a 20 Kohm resistor
with respect to ground in a branch of the DC multi-feeder
distribution
system under test
* Interrupter GFAL-A new field data interpretation
*
Operate the GFAL-B to locate the fault
*
Remove the 20 Kohm resistor
and all test equipment from the DC distribution system
* Return to the classroom for review field test data
*
Q&A. Closing remarks
NOTE:
Besides offering ON-SITE seminars
we also offer investigation into your
DC ground fault problems and issues
and then address your employees with the
issues found and show them how
to address and resolve them.
| Instructor background:
Juan Lopetrone He holds a BSEE degree from California State University of Long Beach, CA where he also taught electronics. His fields of expertise are analog
electronics, micromagnetic circuits, DC (direct current)
ground Mr. Lopetrone has been awarded several
national and international patents on DC ground fault He has more than 25 years field experience
with training, installation and application of DC
ground He has solved problems on ground
fault DC distribution systems at nuclear generation stations,
He was a Instructor for DC ground
fault at ITAC (Information Technology Application Center)
At this time, Mr. Lopetrone is a Sr. Design Electrical Engineer for Samco Engineering. He is in charge of instrument design,
DC ground fault indication and location services and field
training. * Contact us at: Samco EngineeringFountain Valley, CA 92708 Phone: (714) 235 - 5901 E-mail: samcoeng@aol.com Have some question send us an e-mail Return to Training Page ________2008____________________________________________________________________________
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