High-resistance grounding ( HRG ) systems use an NGR to limit the fault current to 25 A or less.
22.
The AC fault current is interrupted at current zero by the highly electronegative SF6 ions absorbing free electrons from the decaying plasma.
23.
Tests show that having a bare grounding conductor adjacent to the insulated wires will conduct the fault current to earth more quickly.
24.
This is of course contingent onthe fuse device design, to be adequate for the voltage level and the available fault current.
25.
Suppliers will carry testing of their cable to demonstrate that it can survive a number of lightning strikes or fault current episodes.
26.
Low-resistance grounding systems use a neutral grounding resistor ( NGR ) to limit the fault current to 25 A or greater.
27.
To prevent this, the fault current is typically limited by a thermal fuse, circuit breaker, or other current limiting device.
28.
Limiting fault current is inherently easier with HVDC than with HVAC . talk ) 03 : 10, 21 May 2012 ( UTC)
29.
The Navy has also committed funding to study design and performance of fault current limited MVDC systems and other operational aspects of MVDC systems.
30.
The benefit of low fault current and continued system operation thereafter is offset by inherent drawback that the fault location is hard to detect.
