GE Industrial Solutions AKD-8 - Manual (Page 3)

GROUNDING SYSTEM OPERATION
(CONT.)
Grounding Resistors
Since ground current is limited by the resistors, the last
section must never be shorted out by the shorting con-tactor
during pulsing.
The resistor must be adjusted at installation so that the
ground current with one ground fault is equal to or slightly
greater than the maximum system capacitance charging
current. (The value obtained with maximum connected load
of the system). If maximum system capacitance current is not
known, refer to "System Capacitance Charging Current"
below for methods to determine the value.
Operation of Equipment
The following instructions will appear on an engraved
nameplate on the equipment door:
Normal
1 - Green light indicates normal condition and equip-ment
energized.
2 - Red light indicates ground fault on system.
Ground Detection
1 - Press reset button. If red light goes out, there is no
ground.
2 - Plug in portable pulsing unit.
3 - Trace pulsing ground current with portable de-
tector.
4 - Remove ground.
5 · Press reset button to remove fault indication.
6 - Unplug portable pulser.
Test
1 - Press test button to simulate ground and to operate alarm
and control circuits. Hold for five seconds or until red
light is lit.
2 - Press reset button after test to return to normal.
Equipment Included In Standard 480V WYE
System With System Neutral Available
1 - Neutral current transformer (optional) (CT)
1 - Meter relay (MR)
1 - Pulsing contactor, set to produce approx. 40 cur-
rent pulsations per minute (fixed or portable) (PC)
1 - Neutral grounding resistors. (RES)
1 - Relay for pulsing contactor. (PCR)
1 - Holding relay, with extra interlocks for remote
alarm. (HR)
1 - Neutral ammeter (optional). (AM)
1 - "Ground Fault" red indicating light. (LT/GRD FLT)
1 - "Normal" green indicating light. (LT/NORM)
1 - "Reset" pushbutton. (PB/RESET)
1 - "Test" pushbutton. (PB/TEST)
1 - Instruction plate on door.
1 - Portable clamp on detector (optional)
System Capacitance Charging Current
The maximum system capacitance charging current must be
known before the high resistance grounding system resistors
can be set for the correct ground current during a fault. If the
maximum system charging current is not known, the value
may be established by the procedures detailed on pages 5 or 6,
whichever is appropriate.
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