20
Operating instructions overview
The ground and test device provides user
access to the primary terminals of the
switchgear equipment. These terminals may
be energized at system voltage and will
deliver maximum system fault (short-circuit)
current. No attempt to operate the ground
and test device should be made without
thoroughly reading and understanding this
instruction manual. Operate the ground and
test device outside of the switchgear unit
and confirm that the sequence of operation
will meet the desired intent before inserting
the ground and test device into the
switchgear unit.
These instructions have been prepared to
enhance operator understanding of the
ground and test device and to suggest one
possible sequence of operation. These
instructions include information on:
l
A1.
Operational checkout of the ground
and test device.
l
A2. System test procedures.
A1. Operational checkout of the ground
and test device
A1.1
These procedures should be
performed as a prerequisite to
each use of the ground and test
device, to verify that the device is
in acceptable operating condition
and to familiarize the user with the
equipment. These operational
checks should be performed with
the ground and test device
withdrawn completely from the
switchgear unit and in an area of
sufficient size to facilitate the
inspection of the device from any
direction. Reference to Table 1:
Type 38-3AH3-GTD ground and
test device types on page 7,
Figures 4-7 and the ground and
test device elementary diagram
Figure 8: Elementary diagram for
device arranged to ground lower
studs type B on page 17 or Figure
9: Elementary diagram for device
arranged to ground upper studs
type D on page 17 (for device
arranged to ground the upper
studs) will aid understanding.
A1.2 The following should be available:
A1.2.1
Ground and test device appropriate
to the studs (upper or lower) which
are to be grounded.
A1.2.2
Remote close-trip pushbutton
control station, consisting of two
normally open pushbuttons and a
long control cable terminated with
plug.
A1.2.3
Suitable voltage source to charge,
close and trip (open) the ground
and test device. Voltage must
match the control voltage indicated
on the device rating plate located
on the front of the ground and test
device.
A1.2.4
Confirm that the correct ground
and test device has been selected
for use. Check the position of the
conductive copper primary studs
and the location of the key lockable
test port slide, compare to the
device elementary diagram and
compare to the switchgear
drawings. If the device has only
one set of primary disconnects
(upper or lower, but not both),
refer to the operation - devices
types E and F instructions.
A1.2.5
Check that the elementary diagram
label on the front of the ground
and test device agrees with the
observed data from step A1.2.4
above and that the device selected
will ground the desired studs in the
switchgear compartment. Compare
findings to Table 1: Type 38-3AH3-
GTD ground and test device types
on page 7 and the discussion of
device types earlier in this
instruction manual.
A1.3
Interlock function. Key interlocks
are provided to enable and control
grounding procedures. For the
purpose of the operational check
procedure, the device is assumed to
be in the "as found" (initial)
condition of the interlocks is
defined as:
