3M CablePipeFault Locator 25502573 Series User Manual

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E. Directional Null (DirNull)
TRACE [2] + Mode [SK] + DirNull [SK Toggle]  
or Menu/OK [5] + Cable/Pipe [SK] + Mode [SK] + DirNull [SK Toggle]
In Directional Null mode, as the operator approaches the cable or pipe, the numerical 
Signal Strength [9] ([8] for 2550 locator) will increase then fall sharply as the receiver 
crosses the target cable or pipe. The Bar Graph [11] ([10] for 2550 locator) fills from 
both sides toward the middle and the receiver speaker volume decreases. As the antenna 
moves off the target path, the Bar Graph [11] ([10] for 2550 locator) opens, the Signal 
Strength [9] ([8] for 2550 locator) increases, and the speaker volume increases. Gain 
adjust is automatic in Directional Null mode.
The center of the DirNull display provides a ‘compass view’ of the target path. An arrow 
will point toward the location of the cable/pipe in 45-degree steps. A solid line will 
appear over the cable/pipe, indicating its orientation to the receiver  handle.
For example:
Figure 1: If the target path is to the right of the 
receiver, and running parallel to the operator, the 
right arrow will display.
Figure 2: If the target path is to the left and in front 
of the operator (not running parallel to the receiver) 
the arrow will point toward the top left side of 
the display.
Figure 3: When the receiver crosses the target path, 
a solid line will appear, instead of arrows, indicating 
the target path and its orientation to the receiver 
handle.
Before marking target path, always use Directional Peak (Dir Pk), Special Peak (Spl Pk) 
or Trace View (T-View) mode to verify location. 
						

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F.  Expanded Mode
VOL [13] (press up arrow)
When the third ring of the speaker icon is dotted 
or broken and ‘xpnd’ appears below the speaker 
icon as shown, the receiver is in “Expanded” 
mode. This mode is used for pinpointing a 
target cable or pipe. The area of response of the 
receiver narrows, allowing the locator to detect 
very small signal changes. Press the Speaker 
Volume Control [13] ([12] for 2550 locator) key 
to activate the “Expanded” mode.
8.  Depth and Current Estimate
Verifying the target path, depth and current can be helpful tools.
•  Pinpoint the cable or pipe being located.
•  Lower the tip of the receiver to the ground and 
press  DEPTH [4].
 
− The depth to the target cable or pipe is displayed 
in the units specified in the receiver set up 
menu. The bold current reading is the relative 
current measurement. This reading can be 
compared to the relative current reading that 
alternately flashes with the frequency on the 
transmitter to help identify the target cable/pipe. 
The highest relative current value will be the 
target cable/pipe and will compare closest to the 
transmitter relative current value. The milliamp 
reading is an actual current measurement.
 
− There are two options for measuring depth. 
Live depth is a continuous measurement. 1-Shot 
Depth is an averaging of the depth reading over 
a short period of time. When in 1-Shot mode, 
the unit will average the depth reading for three 
seconds, and then display the result on the 
display. Press DEPTH [4] to alternate between 
the two modes.
 
− Five depth readings can be saved with the time, 
date and relative current measurements.
• Pressing  Mem Select  [SK] and then Save  [SK] will place each entry in sequential 
order in memory (M1–M5) until five readings have been stored. The unit will 
overwrite saved entries in excess of five, beginning with M1. 
						

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• Optional step: Press Clear All  [SK] to delete all 
stored depth information.
 
− The operator may select a specific memory 
location to store the depth readings by pressing 
Mem Select [SK]. When the preferred location 
appears on the display, press Save [SK]. The 
display and memory location will populate with 
the current information.
 
− Each memory location can be reviewed by 
pressing Mem Select [SK].
•  Press  TRACE [2] or DEPTH [4] to return to Locate 
mode, or wait until receiver automatically returns 
to the Locate  mode.
9. Locating Frequencies
A.  Active Frequencies
Active frequencies are trace signals supplied by a 3M™ Dynatel™ Transmitter 2500 Series 
(577 Hz, 1 kHz, 8 kHz, 33 kHz, 82 kHz or 200 kHz).
•  Select the same frequency that the transmitter is generating.
•  Press Menu/OK [5] (you may have to press Menu/OK  [5] twice to toggle to the 
LOCATE MENU display).
•  Press  Cable/Pipe [SK]
•  Press  Freq [SK]
•  Press  Active  [SK Toggle] until the desired frequency is displayed: (“Active” 577, 1k, 
8k, 33k, 82k or 200k)
•  Press Menu/OK [5] to return to Locate mode.
B.  Power Frequencies
Power frequencies refer to 50 or 60 Hz signals, and their harmonics, that can be traced 
without the use of a transmitter.
60:  Best for general locating of passive power. 
60H (high harmonic): If the 60 choice appears to be responding slowly, or poorly, then 
60H is the second choice for locating passive power.
60L (low harmonic): Third choice for passive power locating. May be used when 60 or 
60H is weak or erratic. 60L may be the best choice when locating primary power cables.
120 Hz: Used for locating rectified AC power signals, often found on pipelines using 
impressed current cathodic protection.
•  Press Menu/OK [5] (you may have to press Menu/OK  [5] twice to toggle to the 
LOCATE MENU display). 
						

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• Press  Cable/Pipe [SK]
•  Press  Freq [SK]
•  Press  Power  [SK Toggle] until the desired frequency is displayed: (“Power” 60, 60L, 
60H, or 120).
•  Press Menu/OK [5] to return to Locate mode.
All U.S. receivers default to 60 Hz.
To set the receiver to detect 50 Hz signals refer to 5.D.  Enabling/Disabling Locating 
Frequencies  section of this manual.
C. Passive Frequencies
The receiver (without a 3M™ Dynatel™ Transmitter 2500 Series) can be used to detect 
some CATV cables (31.5 kHz). (A horizontal-scan television NTSC must be turned on to 
generate this frequency.)
•  Press Menu/OK [5] (you may have to press Menu/OK  [5] twice to toggle to the 
LOCATE MENU display).
•  Press  Cable/Pipe  [SK]
•  Press  Freq [SK]
•  Press  Pasv [SK Toggle]
•  Press Menu/OK [5] to return to Locate mode.
D.  Auxiliary Frequencies
Auxiliary frequencies are signals generated from remote location transmitters, or 
frequency generating transmitters.
• Press Menu/OK [5] (you may have to press Menu/OK  [5]twice to toggle to the 
LOCATE MENU display).
•  Press  Cable/Pipe  [SK]
•  Press  Freq [SK]
•  Press  Aux [SK Toggle] until the desired frequency is displayed; (“Aux” 512, 560, 
333 Hz, or user defined frequencies).
•  Press Menu/OK [5] to return to Locate mode. 
						

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10. Locating in Directional Peak Mode
The following are instructions for locating a buried pipe or cable using the direct connect 
method and the Directional Peak (Dir Pk) mode. Other methods of connection and 
tracing modes/features are explained in previous sections.
Step 1.  Insert the ground rod into the ground, perpendicular to the suspected  
target path.
Step 2. Remove the grounding from the near-end of the target cable/pipe.
Note: Never connect or disconnect the transmitter when the unit is on.
Step 3.  Connect the red lead of the transmitter to the shield, neutral, or deenergized 
target conductor.
Step 4.  Connect the black lead of the transmitter to the ground rod.
Step 5.  Perform a battery check by pressing and holding off  [T-1].
Step 6.  Power on the transmitter by pressing on [T-2] once. This will place the 
transmitter in Ohm-meter mode. An Indicator Flag will be displayed above the 
ohm symbol, Ω, in the Digital Display [T-4]. 
a. A solid tone from the transmitter indicates a complete circuit with a good 
ground.
b.  A beeping tone from the transmitter indicates a usable ground. An attempt 
should be made to improve the ground.
c.  No tone from the transmitter indicates a poor, or no ground. The transmitter 
will display ‘OL’ in this instance. An attempt should be made to improve the 
ground. Verify that the far end is grounded.
Step 7.  Press on Trace  (Frequency on 2550 locator) [T-3] to set the transmitter to  
Trace mode.
Step 8.  Select a frequency on the transmitter by pressing Trace  (Frequency on 2550 
locator) [T-3]. The unit will cycle through the available frequencies (577, 1K, 
8K, 33K, 82K, 200K and ALL).
Step 9.  Press On/Off [1] to power on the receiver.
Step 10.  Press Menu/OK [5] (you may have to press Menu/OK  [5] twice to toggle to the 
LOCATE MENU display).
Step 11.  Press Cable/Pipe  [SK]. 
						

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Step 12. Set the Frequency and Mode of the receiver.
a. Press  Freq [SK]
b.  Select the same frequency on the 
receiver that was selected on the 
transmitter by pressing Active  [SK 
Toggle].
c.  Press Menu/OK [5] to save the setting 
and return to Locate mode.
d.  Press  Mode  [SK Toggle] until Dir Pk  
is displayed.
Step 13.  Stand away from the suspected target path and adjust the Gain [3] down until 
the Bar Graph [11] ([10] for 2550 locator) opens completely.
Step 14.  Walk in a wide circle with your back toward the transmitter (about 10 to 15 feet 
(3 to 4.5 m) away).
 
− Watch the receiver display and listen to the signal. Take note of where the 
receiver detects the strongest Signal Strength [9] ([8] for 2550 locator).
 
− The Bar Graph [11] ([10] for 2550 locator) will close when the unit detects 
a signal, and the arrows will reverse.
 
− Adjust the Gain [3] down if the Bar Graph [11] ([10] for 2550 locator) 
closes completely.
 
− The Signal Strength [9] ([8] for 2550 locator) numbers on the display will 
change with the signal strength (smaller, as you walk away from the target 
path; larger, as you approach the target path).
 
− Make a complete circle around the transmitter. Return to each point in the 
circle that the receiver detected.
Step 15.  Measure the Depth and Current of each point to identify the target path. The 
depth of the target path should be as expected and the relative current should 
compare to the relative current that is alternately flashing with the frequency 
value on the transmitter.
Note: The Relative Current reading will decrease steadily as the locator moves away 
from the transmitter. When using higher frequencies, this decline is more evident.
Step 16.  Adjust the gain so that the Bar Graph [11] ([10] for 2550 locator) responds to 
the target path (open when off path, almost completely closed when directly 
over target).
Step 17.  Trace the cable/pipe at a slow walk while moving the receiver in a side-to-side 
motion, keeping the receiver perpendicular to the ground. 
						

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Step 18. Measure the Depth and Current occasionally to verify target path.
Note: In order to measure the Depth and Relative Current accurately, the operator 
must pinpoint the target pipe or cable, and the receiver handle should be in-line with 
the target path.  
− While in Dir Pk mode, find the highest Signal Strength [9] ([8] for 2550 
locator).
 
− Lower the tip of the receiver to the ground. Twist the receiver left and right 
while watching the Signal Strength [9] ([8] for 2550 locator).
 
− When the highest reading is displayed, the handle of the unit is in line with 
the target pipe or cable.
Occasionally a signal will appear on adjacent cables or pipes. Compare t\
he 
relative and actual current readings (value that is under the relative \
current 
value and in mA units) over each path to help determine the target path. Current 
readings will be significantly less on the adjacent cable/pipe compared \
to the 
target path.
Step 19.  As tracing proceeds, remember that the most powerful signal is near the 
transmitter. As the receiver gets farther away from the transmitter the Signal 
Strength [9] ([8] for 2550 locator) decreases. It may be necessary to readjust the 
gain as needed to be sure there is adequate signal for the receiver to operate. 
Press the Gain [3] up or down when the Bar Graph [11] ([10] for 2550 locator) 
is no longer visible (too little signal) or when the Bar Graph [11] ([10] for 2550 
locator) is closed (too much signal).
Step 20.  Trace the path until you reach a logical termination point (i.e.: terminal, meter, 
cabinet, etc).
11. Locating Active Duct Probes (Sondes)
Step 1.  Press On/Off [1] on the receiver.
Step 2.  Press Menu/OK [5] (you may have to press Menu/OK  [5] twice to toggle to the 
LOCATE MENU display).
Step 3.  Press Cable/Pipe  [SK].
Step 4.  Press Mode  [SK Toggle] to select Special Peak (Spl Pk).
Step 5.  Press Freq [SK].
Step 6.  Press Active  [SK Toggle] to select the 33kHz frequency (for a 33 kHz Sonde 
or  ADP (Active Duct Probe)).
Step 7.  Press Menu/OK [5]. 
						

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Step 8. With the receiver handle perpendicular to the conduit path, locate the ADP 
position by moving along the path until the strongest Signal Strength [9] ([8] 
for 2550 locator) is found. Adjust Gain [3] up or down when the Bar Graph 
[11] ([10] for 2550 locator) remains either fully open or fully closed.
Step 9.  Refer to the ADP operating instructions for further information.
A. Determining Active Duct Probe Depth
Step 1.  Place the tip of the receiver on the ground directly above the located ADP 
position.
Step 2.  Maintain the handle orientation perpendicular to the target path.
Step 3.  Press DEPTH [4].
Step 4.  Press Sonde Depth [SK] to read ADP Depth.
 
− The depth to the ADP is displayed in 
units as specified in the receiver set up 
menu.
 
− Five Sonde depth readings can be saved 
with the time and date measured. Press 
Mem Select [SK] after the Sonde depth 
displays.
 
− Press Mem Select [SK] to select a 
specific memory location (M1–M5) or 
select Save [SK]. Save [SK] will place 
each entry in sequential order in memory 
(M1–M5) until five readings have been 
stored. The unit will overwrite saved 
entries in excess of five, beginning 
with M1.
Step 5.  Optional step: Press Clear All  [SK] to delete all saved depth readings.
Step 6.  Press Mem Select  [SK] to select a specific memory location (M1 - M5) to store 
the depth readings.
Step 7.  When the preferred location appears on the display, press Save  [SK]. The 
display and memory location will populate with the current information.
Step 8.  Each memory location can be reviewed by pressing Mem Select  [SK].
Step 9.  Press Cable Depth [SK] to switch to the cable depth display, or Menu/OK [5] to 
return to Locate Mode.
Note: During a depth measurement, the display will exhibit ‘- -’ when the received 
signal is too low, too high or erratic. 
						

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12. Locating Buried Sheath Faults And Earth 
Return Faults  
(3M™ Dynatel™ Models 2573 and 2573-iD only)
Note: Remove (disconnect) both the near-end and far-end grounding from the  
test section.
A.  Transmitter Setup
Note: Do not make any connections while the transmitter is on. Fault loc\
ation will not 
work unless the near-end and far-end grounds are disconnected.
Note: This method only works on direct buried cables/conductors. It will\
 not work if 
the cables/conductors are faulted inside of a conduit, such as a PVC con\
duit.
Step 1.  Attach the red clip to the earth-faulted conductor of the cable or conductor 
under test.
Step 2.  Place the ground rod behind the transmitter and in parallel with the target path.
Step 3.  Connect the black clip to the ground rod behind the transmitter.
Step 4.  Press and hold On/Off [1] to perform a battery test.
Step 5.  Press on [T-2] once to power on the transmitter. This will place the transmitter 
in Ohm-meter mode. An Indicator Flag will be displayed above the ohm 
symbol,  Ω, in the Digital Display [T-4].
 
− The resistance of the fault will be displayed in ohms on the transmitter 
Digital Display [T-4].
 
− Resistance less than 50KΩ = Significant fault exists
 
− Resistance 50KΩ to 1.0MΩ = High resistance fault exists (May or may not 
cause problems yet, but gets worse with time.)
 
− Resistance greater than 1.0MΩ = No significant fault exists
Note: The fault locating limit is 2.0MΩ, although the transmitter's ohm-meter mode 
can display a fault resistance up to 10MΩ.
Step 6.  Press on [T-2] again, to select Fault mode.
 
− An Indicator Flag will be displayed above the fault locating symbol in the 
Digital Display [T-4]. (as shown in the illustration below)
  off
+
-
o
 
Trace
onon Output Level
DynatelTM257 3
Flag
Note: Two active line locating frequencies, 577 Hz and 33 kHz, are simultaneously 
transmitted with the fault finding signal. This allows convenient switching back and 
forth between fault finding mode and cable/pipe locate mode on the receiver during 
fault finding without returning to the transmitter. The transmitter display [T-4] will 
flash between 577 Hz and 33 kHz. It does not display the fault finding frequencies. 
						

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B. Pinpointing the Buried Fault
Step 1.  Connect the 3M™ Earth Contact Frame to the External Jack [15] ([14] for 2550 
locator) of the receiver using the Earth Contact Frame cable (4 ft. (1.2 m) cable).
Step 2.  Press On/Off [1] to power on the receiver. The receiver display screen will 
display  “Fauly Calibrating” for about 5 seconds.
Step 3.  Press Menu/OK  [5].
Step 4.  Press Fault  [SK] to select Fault mode.
Step 5.  Hold the receiver in one hand and the Earth Contact Frame in the other with the 
solid green-banded leg of the frame toward the test section. Near the location 
of the ground rod (about one Earth Contact Frame width away from the ground 
rod, slightly to the side and towards the faulted cable.), insert the Earth Contact 
Frame probes fully into the ground in line with the target path.
Step 6.  Press REF [SK] to record the fault  Signal Strength [9] ([8] for 2550 locator) 
level reference. The signal level will be recorded in the box above REF  [SK] 
on the display. This reference indicates the Signal Strength [9] ([8]) for 2550 
locator) level at the ground rod. When the operator reaches the major fault 
location, the Signal Strength [9] ([8]) for 2550 locator) indicated on the receiver 
will be very close (within 12dB) to this reference signal strength level.
Step 7.  Continue along the cable path, re-inserting the Earth Contact Frame probes 
every few steps while watching the receiver bar graph. The bar graph on the 
receiver will fill toward the right side of the display (green Fault Finding 
Direction Indicator [8] (See illustration below)), indicating that the fault is 
ahead of the operator (in the direction of the green-banded leg of the Earth 
Contact Frame).
 
Move in direction of red-banded leg  
of 3M™ Earth Contact Frame.
Move in direction of green-banded leg   of 3M™ Earth Contact Frame.
Transmitter Signal Green Band
Red-and-White-Striped Band
Ground Fault location