3M CablePipe Locating Techniques Manual

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4. Applying Signal to Telephone Cable: Dyna-Coupler Method
4.1 The Dyna-Coupler puts signal selectively on a cable by clamping around it.  This eliminates the
need to disconnect the cable.  Do not use the Dyna-Coupler on a cable that has the shield
ungrounded at both ends.
4.2 Place the Dyna-Coupler on the cable between
the ground bonding and the point where the
cable enters the earth as shown (A).  Note
that if you place the Dyna-Coupler above the
bond, the signal travels to ground, and not
onto the...

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4.4 If the cable is long, remove the bonding
and signal goes both ways as shown.
4.6 Several cables grounded at a common
point present no problem for the Dyna-
Coupler method. Even though signal is
coupled into each cable, the cable with
the Dyna-Coupler is clearly
identifiable because it has the strongest
signal. 4.5 Clamping the Dyna-Coupler to a cable
with drop lines or laterals puts full
signal on the cable until the junction
point. The signal may split evenly at
the lateral as shown. When...

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5. Locating Slack Loops and Butt Splices
5.1 To identify the presence of a slack loop or
butt splice in a cable path, first locate and
mark the cable path.
5.2 Find the strongest response over the marked
cable path and reset the gain.
5.3 Retrace the cable path with the Receiver
held so the handle is perpendicular to
(across) the cable path, as shown. When the
Receiver passes over a slack loop or butt
splice, the signal increases and the bar graph
closes. Mark each response. Whenever you
encounter...

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7. Locating Cables from Pedestals
7.1 To locate a single cable path from a pedestal, follow these steps:
7.2 At the pedestal, apply tracing signal on the target cable using the Dyna-Coupler method.  If the
header in the pedestal is not grounded, use the ground rod and ground extension cable to ground
it.
7.3 Walk 10 to 25 feet away from the pedestal.  Hold the Receiver so that the display end of the
handle points directly to the pedestal.  Start walking in a circle around the pedestal with the...

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8. Locating Service Drops
8.1 When locating the path of a service drop from a house or other building, it is more convenient to
apply signal at the house or building.  Connect the Transmitter using the direct-connect method.
Use the standard tracing techniques described earlier.
9. Locating an Open End
9.1 To locate an unterminated or open end of a cable or drop, follow these steps.
9.2 If the cable is bonded to ground at the access point, connect the Transmitter using the Dyna-
Coupler method....

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11. Pair Identification
11.1 This procedure identifies individual conductors within the same cable.  It uses the Dyna-Coupler,
so none of the pairs will need to be cut.  The use of the high frequency will also allow tagging of
conductors in a wet pulp section.
11.2 At a splice or access, use the Transmitter to put signal on the pair to be identified using the Dyna-
Coupler. To minimize signal canceling and disruption on active pairs, clamp the Dyna-Coupler
around both tip and ring of the pair and make...

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12. Locating Splits
12.1 To locate the splice where a split occurs, attach the Transmitter to tip and ring of one pair of the
split. Strap the tips and rings of both pairs at a far-end access beyond the splice.
12.2 On the Transmitter, select the tone mode and the low frequency.
12.3 Using either the Receiver, a toning amplifier or a toning coil, detect a weak tone from the
Transmitter to the split, and strong tone from the split to the strap.
12.4 To verify that the split has been located, attach the...

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A. Can the Fiber Be Traced?
13.1 Fiber optic cables consist of fragile optical fibers encased in a strengthened outer member. The
internal sheath of the cable may or may not be metallic. If it is not metallic, the manufacturer may
include a metallic strength member (wire) within the sheath.  Some fiber optic cables have no
internal metal structure, in which case the contractor installing the cable may pull an insulated
wire through the underground duct with the fiber optic cable. If a metallic...

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B. Applying the Trace Signal
13.3 If the office installation includes a rack-mounted transmitter, check to see if your Receiver has the
same frequency.  Some Receivers will receive 512 Hz and 560 Hz as well as 577 Hz. To use the
transmitter, attach it to the sheath or strength member of the fiber optic cable to be traced and turn
it on. If the transmitter frequency does not match the Receiver, or a rack-mounted transmitter is
not available, attach the Dynatel Transmitter at the CO/Remote Terminal...

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13.8 Maximum tracing signal is obtained
by disconnecting the bonding
strap(s) from the ground point before
attaching the Transmitter, but local
practice may not allow this.  In this
case, the signal splits between the
incoming cable, outgoing cable, and
the ground point, thus reducing the
tracing range.
13.9 Use high level output if tracing fiber
optic cable longer than .5 miles.
C. Tracing the Fiber Optic Cable
13.10 When tracing from a CO or Remote Terminal office, move to the cableÕs expected exit...