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HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

(OP)
Hello:

I am working on sizing the neutral grounding resistor for a high resistance ( through a distribution transformer) grounded generator. In the first steps, the total system charging current must be determined. I am first gathering the contributions from large cables (500, 750MCM), and wondering if you can please verify that zero sequence capacitance of the cable should be used to determine the charging current. In general, is the zero sequence impedance (of any connected device) the correct to use? Thanks for your help.

RE: HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

The resistor would normally be sized based on the maximum fault current and duration rather than the quiescent current.
Regards
Marmite

RE: HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

But that maximum fault current must be higher than the charging current, so the question is relevant.

I really don't know, but I suspect that positive sequence charging current is sufficient.

RE: HIgh Resistance Grounding: sanity check on choosing cable sequence impedance

See also:
GROUND FAULT PROTECTION ON UNGROUNDED AND HIGH RESISTANCE GROUNDED SYSTEMS-APPLICATION GUIDE
Post Glover Resistors
Appendix 1.Pg 15
http://www.google.co.il/url?sa=t&rct=j&q=ground%20fault%20protection%20on%20ungrounded%20and%20high%20resistance%20grounded%20systems-application%20guide&source=web&cd=2&sqi=2&ved=0CFUQFjAB&url=http%3A%2F%2Fwww.postglover.com%2FLiterature%2FHR003-05_High_Resistance_Ground_Gde.pdf&ei=BzO2T969INSX0QXa_pW_Cg&usg=AFQjCNGyhXtaRlTgGtTCF813t8hLYX1mhA

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