Cable Fault Location System Aerial Fault Location QR V 1.2
1
Cable Fault Location System - Aerial Fault Location Quick Reference
This quick reference provides abbreviated guidelines on the use of the Cable Fault Location System (Snoopy) for locating
Aerial resistive cable faults.
S
AFETY
All prescribed safety precautions and procedures must b e observed while using the SR-101 equipment.
Failure to do so can result in serious injury or death.
T
YPES OF
F
AULTS
The following resistive faults may be located:
•
Short Tip connected to Ring
•
Cross Tip or Ring of one pair is connected to the Tip or Ring of another pair
•
Split
Tip or Ring of one pair is split with the Tip or Ring of another pair
✓
The cable length beyond the fault should be as short as possible.
F
AULT
P
RE
-T
ESTING
The technician must identify the type of fault, estimate the distance, and section the pair(s) using local practice
procedures. The far end of the section should be less than 35% of the section length if possible.
P
AIR
S
PLITS
The diagram below shows a split and how to place temporary short at the far end of the section and connect the
transmitter clips.
Locating a Split
TIP
RING
R
T
TIP
RING
R
T
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
Temporary
Short
Locating a Split
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
Temporary
Short
Locating a Split
TIP
RING
R
T
TIP
RING
R
T
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
Temporary
Short
Locating a Split
TIP
RING
R
T
TIP
RING
R
T
Pair 1
Pair 2
Temporary
Short
F
AULT
L
OCATION
Transmitter Setup
1.
The ST-101 should be positioned at one end of the cable section. The length past the fault,
the far-end opposite the transmitter, should be minimized, to reduce carry-by of the tone.
2.
Connect the transmitter clips to the fault as follows:
Fault
Connections
Short
Tip and Ring of the shorted pair.
Cross
The two wires that are crossed
Split
The split wires. See paragraph 4.
3.
The transmitter “Auto
-
Set” function serves as a general guideline for
frequency and
[LEVEL]
settings.
4.
Turn on the transmitter and use Auto-Set for the transmitter initial frequency and power
settings or use 335Hz. The
PWR OUT
indication should be near mid-scale.
5.
The following guidelines help manually adjust the frequency based on the cable section
length if needed:
Freq (Hz)
500
1000
5000
10000
20000
40000
145
95,900
48,000
19,200
9,600
4,800
2,400
335
41,500
20,800
8,300
4,200
2,100
1,000
577
24,100
12,100
4,800
2,400
1,200
600
987
14,100
7,000
2,800
1,400
700
400
2000
7,000
3,500
1,400
700
300
200
Section Length (Feet)
Resistance Limits In Ohms (
Ω
)
