* DC multi-feeder distribution systems single line drawings
* 24 VDC, 125 VDC and 250 VDC multi-feeder distribution systems
* DC multi-feeder distribution system, load current and ground fault current path
* Traditional methods to indicate DC ground faults, light bulbs, meters, relays
* Voltage imbalance method to indicate DC ground faults
AM break
* Single and multiple ground faults and their display
characteristics
* "Blind spot", failure of the DC voltage imbalance method to indicate multiples ground faults
* Finding the value of the ground fault resistance from each polarity with respect to site ground, new method
* Using the GFAL-A unit to find the value of the ground fault resistances from each polarity
Noon break
* Review early material, Q&A
* Locating DC ground faults, generic procedures
* Theory of the AC injection signal method to locate DC ground faults
* Stray capacitance on DC multi-feeder distribution system, adverse effects on AC injection signal methods
Probes
used with the AC injection signal method to locate DC ground fault that can trip a Unit
* Theory of the DC interrupted signal method to locate DC ground faults, safety considerations
* Magnetic interferences on DC probes used to locate DC ground faults,
adverse effects on the DC interrupted current method, magnetic shields
* New method and instrument, the GFAL-A/B to analyze
and locate DC ground faults
Afternoon break
* Set -up in the classroom the test "Jig" and the GFAL-A and the GFAL-B units
* Locating DC ground faults with the DC tracking signal method on 125 VDC multi-feeder
DC distribution system test "Jig"
* Utilizing an external power source to troubleshoot
de-energize circuits
* Follow the tracking signal inside magnetic and non-magnetic conduit with the GFAL-B instrument
End of the first day of training
__________________________________________
Second Day, AM
* Review the training notes from the previous day, Q&A
* Set-up in the classroom the test "Jig" the GFAL-A and the GFAL-B units
* Review a classroom test procedure for the students to perform a hands-on test
* Student
will perform a classroom test with the GFAL-A and the GFAL-B units
to locate single and multiples DC ground faults
AM break
* Review the test procedure for the students to perform a field test (or a 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 lab area is not available the classroom test set-up
will be used for this portion of the training
* Scope of the site test (review all safety guidelines)
* Carry the GFAL-A/B instrument to a site to perform a field test procedure
* Students
will install the GFAL-A, Analyzer/Interrupter unit on the Battery
Assembly of the
DC distribution
system as explained in the field test procedure
* Students will operate the GFAL-A unit and collect field test data
* Students will operate the GFAL-B unit (Detector/Display) Unit and collect field test data
Noon break
* Students
will install a 20 Kohm resistor from one polarity
of the DC multi-feeder distribution
system
with respect to site ground
* GFAL-A Interrupter unit new field data interpretation
* Students will operate the GFAL-A and GFAL-B units to locate the 20 Kohm ground fault resistor
* Remove the 20 Kohm resistor
and all test equipment from the DC distribution system.
Inform the Control Room the end of the test
* Return to the classroom for review field test data
*
Q&A. Closing remarks
NOTE:
Besides offering ON-SITE training 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, micro magnetic 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, substations, fossil fuel generating plants and cogeneration facilities all over the United States. He was an 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 ________2010____________________________________________________________________________
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