Specifications

COMPLETE REVISION
PIP ELSGS01
July 2004 Design and Fabrication of High-Resistance Grounding System (600 Volts or Below)
Process Industry Practices Page 5 of 11
b. Neutral current transformer
c. Test push-button to simulate a ground-fault condition
d. Reset push-button to reset the system
e. A red indicating light to indicate ground fault
f. A green indicating light to indicate normal condition
g. A ground current test loop and a test current test loop in resistor wiring
that allow the use of a clamp on ammeter to measure ground current
h. A provision for selection of normal or pulse operation
i. A holding relay with two additional normally open and two normally
closed contacts for use by the purchaser. Holding relay contacts shall be
connected to terminal blocks for purchaser connections.
j. Unless otherwise specified on the purchaser’s data sheet,
PIP ELSGS01D, a switchgear class overcurrent relay in a drawout case
with a minimum pickup current of 0.5 amperes or less
k. A filter to eliminate nuisance alarms if the overcurrent detection and
alarm system is not inherently insensitive to adjustable speed drive
carrier frequency and other harmonics
l. An undervoltage relay with two normally open and two normally closed
contacts for remote indication of loss of control power. The contacts
shall be connected to terminal blocks for purchaser’s connections.
m. A pulsing contactor set to produce approximately 40 current pulsations
per minute
n. A timer for the pulsing contactor
o. A control power transformer with secondary fuses
4.4.2 All indicating lights shall be replaceable high-brightness, single-element
light-emitting diode (LED) lamps. A push to test function shall be provided
for each light.
4.5 Disconnect Switch
4.5.1 The grounding system shall have a disconnect device for isolation of control
power.
4.5.2 If specified on the purchaser’s data sheet, PIP ELSGS01D, for a wye system,
a disconnect switch shall be provided for the neutral connection.
4.5.3 If specified on the purchaser’s data sheet, PIP ELSGS01D, for a delta
system, a disconnect switch shall be provided for the neutral deriving
transformer.
4.5.4 The disconnect device shall be prominently marked to warn that, if the
device is opened, the power system will be ungrounded.