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GridAdvisor™ Series II smart sensor installation instructions
IL915001EN
April 2019
Eaton.com
Installation procedures
Underground distribution circuits
Primary cable preparation
Proper primary cable preparation is necessary for the
GridAdvisor Series II smart sensor acting as a faulted circuit
indicator to work reliably on underground distribution circuits.
The sensor can be used on concentric neutral, tape shield, or
drain wire cable. If the cable does not provide a return path
for the fault current, the sensor can be installed directly over
the cable. If used on concentric neutral cable, or if the cable
shield provides a return path for the fault current, the sensor
will not reliably detect a fault and will require the use of a tape
shield or drain wire adapter. When used, the adapter must be
installed approximately 3.5 inches below the elbow to allow
space for mounting the sensor on the cable.
One of the following four methods is preferred for installation
on concentric neutral primary cable:
Method 1 (refer to Figure 2A)
1.
Attach one or two strands of the concentric neutral
wrapped around the cable to the tie-off tab on the elbow.
2.
Terminate all of the remaining neutral wires
approximately 6 inches below the elbow.
3.
Pull the neutral wires straight up and terminate them
again just below the elbow. The wires should then be
bent back down the cable (commonly referred to as
“double back”).
4.
Terminate the ground wires approximately 6 inches
below the elbow.
Note:
The sensor is installed over the “double back” neutral
wires to cancel the effect of current in the neutral. The
exact trip value is dependent on the overall diameter of
the “double back” neutral wires.
Figure 2. Recommended methods of concentric neutral
primary cable preparation
Method 2 (refer to Figure 2B)
1.
Attach one or two strands of the concentric neutral
wrapped around the cable to the tie-off tab on the elbow.
2.
Terminate all of the remaining neutral wires just below
the elbow. The balance of the neutral wires should be
gathered together and “double backed” down the cable
and grounded.
3.
The sensor is installed over the “double back” neutral
wires to cancel the effect of current in the neutral. The
exact trip value is dependent on the overall diameter of
the “double back” neutral wires.
Method 3 (refer to Figure 2C)
1.
Attach one or two strands of the concentric neutral
wrapped around the cable to the tie-off tab on the elbow.
2.
Terminate and ground all of the remaining neutral wires
approximately 6 inches below the elbow.
Method 4 (refer to Figure 2D)
1.
Arch one or two strands of the concentric neutral
wrapped around the cable and attach it to the tie-off tab
on the elbow.
2.
Ensure that the arch is large enough to go around the
outside sensor when the sensor is installed.
In some installations, improper preparation of the primary
cable will result in an inoperable sensor as a faulted circuit
indicator (FCI) (Figure 3). The magnetic field, due to current in
the center conductor, will be canceled by the current in the
concentric neutral wires.
Do not place the fault indicator as shown in Figure 3. Doing
so will prevent the sensor from working properly.
Figure 3. Incorrect methods of concentric neutral primary
cable preparation
ELBOW
TIE-OFF
TAB
ELBOW
LOCATE
THE SENSOR
PORTION OF
THE FAULTED
CIRCUIT
INDICATOR
(in the outlined
area)
NEUTRAL
WIRES
TERMINATED
NEUTRAL
WIRES
A
B
C
D
A
B
