IPC C-103EM, Инструкция по эксплуатации

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INSTRUCTION MANUAL
C-103EM
Turbo Sleuth Ground Fault Locator
9 September 2002
15
(2) Neutral grounding devices shall be placed in a location that is accessible only to qualified
persons to perform inspection, testing, and maintenance of the neutral grounding device.
(3) Neutral grounding devices shall be placed in a location so that heat dissipation from the
device under ground fault conditions will not damage or adversely affect the operation of the
device or other equipment.
(4) Where neutral grounding devices are used, warning signs indicating that the system is
impedance grounded and the and the maximum voltage at which the neutral may be
operating relative to ground shall be placed at the:
(a) Transformer or generator, or both; and
(b) Consumer’s service switchgear or equivalent; and
(c) Supply authority’s metering equipment.
10-1108 Conductors Used with Neutral Grounding Devices.
(1) The conductor connecting the neutral grounding device to the neutral point of the
transformer, generator, or grounding transformer shall be:
(a) Insulated for the nominal system voltage; and
(b) Identified white or natural grey; and
(c) Sized to conduct the rated current of the neutral grounding device, and in no case
less than No. 8 AWG; and
(d) Installed in accordance with other appropriate Rules of this Code.
(2) The conductor connecting the neutral grounding device to the neutral point of the
transformer, generator, or grounding transformer shall not be grounded.
(3) The conductor connecting the neutral grounding device to the system grounding electrode
shall be:
(a) A copper conductor which shall be permitted to be insulated or bare; and
(b) Identified green if insulated; and
(c) Sized to conduct the rated current of the neutral grounding device, and in no case
less than No. 8 AWG in size; and
(d) Installed in accordance with other appropriate Rules in this Code.
CAN/CSA M421-93 Use of Electrici ty in Mines
Pg. 26
4.5.2
Neutral-grounding Devices
The neutral grounding device shall be continuously monitored by a device that will trip the supply if an
open circuit in the neutral grounding device occurs.
Pg. 29
4.7.3.4.1
Resistance Grounding
Where on-board three-phase, isolation power transformers larger than 20 kVA and operating at voltages in
excess of 300 V are used, the following requirements shall apply:
(a) Except as permitted by item (g), either a direct or derived neutral shall be grounded through a resistor
at the power source to limit the prospective ground-fault current to 25 A or less.
(b) A grounding circuit shall originate at the grounded side of the resistor and extend along with the power
conductors to ground the frames of all electrical apparatus supplied from the circuit, except where the
steel structure provides the ground-return path as permitted by clause 4.7.5 (b).
(c) The size of the grounding conductors may be reduced provided the ampacity exceeds the prospective
ground-fault current.