Specifications

COMPLETE REVISION
PIP ELSGS01
July 2004 Design and Fabrication of High-Resistance Grounding System (600 Volts or Below)
Process Industry Practices Page 3 of 11
4. Requirements
4.1 General
4.1.1 Unless otherwise specified on the purchaser’s data sheet, PIP ELSGS01D,
the grounding system shall ground the power system using high-resistance
grounding principles so that the ground fault current is limited to an
adjustable value of approximately 1 to 5 amperes during a phase-to-ground
fault condition.
4.1.2 The grounding system shall be capable of producing a pulsing current into
the ground fault that can be traced to the fault with a multi-range portable
clamp-on ammeter. Pulsing current shall be at least 3 amperes more than the
setting of the ground fault current.
4.1.3 An adjustable time delay for ground fault alarm activation of approximately
0.2 to 2.0 seconds shall be provided to allow override of a momentary
ground fault alarm condition.
4.1.4 The grounding system shall continuously monitor the ground current in the
electrical system neutral and indicate ground fault by means of an
overcurrent relay.
4.1.5 A resistor shall be provided to initiate a controlled fault on one phase if the
system test push button is pressed. This test resistor circuit shall be inhibited
if a system ground fault is indicated by the ground fault relay.
4.1.6 The grounding system shall have normally closed (open to alarm) contacts to
provide remote indication of ground fault and loss of control voltage
conditions.
4.1.7 Unless otherwise specified on the purchaser’s data sheet, PIP ELSGS01D, a
control power source from within the equipment shall be provided.
4.1.8 Unless otherwise specified on the purchaser’s data sheet, PIP ELSGS01D,
the grounding system shall be designed for operation on a 480-volt line-to-
line (L-L) system.
4.1.9 The grounding system shall be suitable for use on a wye or delta
configuration as specified on the purchaser’s data sheet, PIP ELSGS01D.
4.1.10 If a delta system configuration is specified, three (3) single-phase neutral-
deriving, dry-type 220°C insulation, 80°C rise, 120-volt secondary
transformers shall be provided.
4.1.11 Equipment shall be labeled by a nationally recognized testing laboratory
(NRTL).
4.2 Site Conditions
4.2.1 The grounding system shall operate at the altitude indicated on the
purchaser’s data sheet, PIP ELSGS01D, without de-rating.
4.2.2 The grounding system shall be designed for the building code and seismic
zone indicated on the purchaser’s data sheet, PIP ELSGS01D.