INSTRUCTION MANUAL
C-103EM
Turbo Sleuth Ground Fault Locator
9 September 2002
13
11. Definitions and applicable Standards.
11.1.
Grounding means a permanent and continuous conductive path to the earth with sufficient
ampacity to carry any fault current liable to be imposed on it, and of a sufficiently low impedance to limit
the voltage rise above ground and to facilitate the operation of protective devices in the circuit;
11.2.
Bonding means a low impedance path obtained by permanently joining all non-current -
carrying metal parts to assure electrical continuity and having the capacity to conduct safely any current
likely to be imposed on it;
12. NEC 2002 pg. 70-87-88
12.1.
High-Impedance Grounded Neutral Systems.
High-impedance grounded neutral systems in which a grounding impedance, usually a
resistor, limits the ground-fault current to a low value shall be permitted for 3-phase ac
systems of 480 volts to 1000 volts where all of the following conditions are met:-
12.1.1. The conditions of maintenance and supervision ensure that only qualified persons will
service the installation.
12.1.2. Continuity of power is required.
12.1.3. Ground detectors are installed on the system.
12.1.4. Line-to neutral loads are not served.
12.2.
High-impedance grounded neutral systems
shall comply with provisions (a) through (f).
12.3.
Grounding Impedance Location.
The grounding impedance shall be installed between
the grounding electrode conductor and the system neutral. Where a neutral is not
available, the grounding impedance shall be installed between the grounding electrode
conductor and the neutral derived from a grounding transformer.
12.4.
Neutral Conductor.
The neutral conductor from the neutral point of the transformer or
generator to its connection point to the grounding impedance shall be fully insulated.
12.5.
The neutral conductor shall have an ampacity of not less than the maximum current rating
of the grounding impedance. In no case shall the neutral conductor be smaller than No. 8
copper or No. 6 aluminum or copper-clad aluminum.
12.6.
System Neutral Connection.
The system neutral connection shall not be connected to
ground except through the grounding impedance.
12.7.
Neutral Conductor Routing.
The conductor connecting the neutral point of the
transformer or generator to the grounding impedance shall be permitted to be installed in
a separate raceway. It shall not be required to run this conductor with the phase
conductors to the first system disconnecting means or overcurrent device.
Summary of Contents for C-103EM
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