Specifications

PIP ELSGS01
COMPLETE REVISION
Design and Fabrication of High-Resistance Grounding System (600 Volts or Below) July 2004
Page 6 of 11 Process Industry Practices
4.6 Resistors
4.6.1 The grounding system shall have continuous rated, wire or edge wound
resistors of corrosion resistant material.
4.6.2 Resistors shall be rated to operate at 277-volts AC minimum.
4.6.3 For systems operating at 550 and 600 volts, resistors shall be rated at
350 volts AC minimum.
4.6.4 Resistor assembly shall have a minimum of four adjustable taps or shall be
continuously adjustable.
4.6.5 Resistors shall be mounted on standoffs designed so that the surface
temperature of the surrounding enclosure does not increase more than 20°C
above ambient temperature during fault conditions.
4.7 Portable Ground Current Detector
4.7.1 The grounding system shall be designed to function in conjunction with a
portable, clamp-on ground current detector.
4.7.2 Unless otherwise specified on the purchaser’s data sheet, PIP ELSGS01D,
the system shall be furnished with a portable ground current detector.
4.7.3 Portable ground current detector shall be provided with:
a. A multi-range switch for accurate measurement of pulsing current
b. A large window that is suitable for conduits with a nominal diameter of
up to 5 inches
c. A removable arm to facilitate use of the detector in limited spaces in
which conduits/cables are close together
d. A shorting switch to provide transient protection while detector is being
positioned around conductors
e. A closed magnetic field to minimize effects of stray fields
f. An insulated handle for use on systems rated up to 4,160 volts nominal
g. A carrying case
4.8 Wiring
4.8.1 General
4.8.1.1 All wiring shall be stranded copper conductors.
4.8.1.2 Power and control wiring shall be #14 AWG minimum.
4.8.1.3 Wiring from transformer neutral to switchgear shall be #8 AWG,
minimum.
4.8.1.4 Current transformer (CT) wiring shall be #10 AWG conductor
minimum, unless device terminals do not allow the use of #10
conductor.