Megger L1070, L1071 Instruction Manual

AVTM651070

Rev B

Nov 2006

Instruction Manual

L1070 and L1071

Portable Locator

Catalog No. 651070 and 651071

Read this entire manual before operating.

M

Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403-2329
U.S.A.

610-676-8500

www.megger.com

L1070 and L1071

Portable Locator

Instruction Manual

Copyright© 2006 by Megger. All rights reserved.

The information presented in this manual is believed to be adequate for the intended use of the product.
If the product or its individual instruments are used for purposes other than those specified herein,
confirmation of their validity and suitability must be obtained from Megger. Refer to the warranty
information below. Specifications are subject to change without notice.

WARRANTY

Products supplied by Megger are warranted against defects in material and workmanship for a period of
one year following shipment. Our liability is specifically limited to replacing or repairing, at our option,
defective equipment. Equipment returned to the factory for repair must be shipped prepaid and insured.
Contact your MEGGER representative for instructions and a return authorization (RA) number. Please
indicate all pertinent information, including problem symptoms. Also specify the serial number and the
catalog number of the unit. This warranty does not include batteries, lamps or other expendable items,
where the original manufacturer’s warranty shall apply. We make no other warranty. The warranty is
void in the event of abuse (failure to follow recommended operating procedures) or failure by the
customer to perform specific maintenance as indicated in this manual.

M

Valley Forge Corporate Center
2621 Van Buren Ave
Norristown, PA 19403-2329

610-676-8500 (Telephone)
610-676-8610 (Fax)

www.megger.com

Table of Contents

1............................................................................................................................................................. 1

Introduction....................................................................................................................................... 1

Receiving Instructions.................................................................................................................... 1

General Information ...................................................................................................................... 1

2............................................................................................................................................................. 3

Safety ................................................................................................................................................. 3

Precautions .................................................................................................................................... 3

3............................................................................................................................................................. 5

Specifications..................................................................................................................................... 5

Receiver......................................................................................................................................... 5

Transmitter.................................................................................................................................... 6

Battery Charger.............................................................................................................................. 7

4............................................................................................................................................................. 9

Transmitter Operation....................................................................................................................... 9

Controls and Indicators (Fig. 1)..................................................................................................... 9

Ac Resistance Indications............................................................................................................. 10

Transmitter Rechargeable Battery Option.................................................................................... 11

Selecting the Locating Method..................................................................................................... 12

Power Utility Connection............................................................................................................. 13

Telco Circuit Connection............................................................................................................. 14

Flexible Coupler Connection........................................................................................................ 15

Inductive Connection................................................................................................................... 16

Direct Connection........................................................................................................................ 17

Notes on Selecting the Tracing Signal.......................................................................................... 17

Continuously Grounded Circuit................................................................................................... 18

Telephone Direct Shield Connection............................................................................................ 19

Telephone Direct Pair Connection............................................................................................... 19

5........................................................................................................................................................... 21

Receiver Operation.......................................................................................................................... 21

Controls and Indicators................................................................................................................ 21

Locating Cable or Pipe................................................................................................................. 24

Peak Mode Locating..................................................................................................................... 24

Null Mode Locating..................................................................................................................... 25

Absolute Signal Strength.............................................................................................................. 26

Signal Strength Adjusted for Depth (Current Measurement)........................................................ 27

Gain Change Indication............................................................................................................... 28

Passive 50/60 Hz Locating........................................................................................................... 28

Push-Button Digital Depth.......................................................................................................... 28

Depth Measurement 45° Angle Method....................................................................................... 29

Offset Magnetic Field Identification............................................................................................. 30

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6........................................................................................................................................................... 31

Fault Locating with the L1070/L1071.............................................................................................. 31

Introduction................................................................................................................................. 31

Signal Return through an Insulated Fault...................................................................................... 31

Setting the Transmitter to Fault Mode.......................................................................................... 32

Setting the Receiver to Fault Mode............................................................................................... 32

Ground Return Probe .................................................................................................................. 32

Ground Return Probe Insertion................................................................................................... 33

Ground Return Probe Fault Locating........................................................................................... 33

7........................................................................................................................................................... 35

Service.............................................................................................................................................. 35

Maintenance................................................................................................................................. 35

Repair........................................................................................................................................... 35

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List of Figures

Figure 1: Transmitter Controls and Indicators.................................................................................... 9

Figure 2: Multiple Grounded Circuit Connection............................................................................. 13

Figure 3: Multiple Ground Power Utility Application....................................................................... 14

Figure 4: Multiple Ground Telco Application................................................................................... 14

Figure 5: Flexible Coupler Connection............................................................................................. 15

Figure 6: Inductive Connection........................................................................................................ 16

Figure 7: Inductive Connection 30° Angle........................................................................................ 16

Figure 8: Direct Connection............................................................................................................. 17

Figure 9: Continuously Grounded Circuit......................................................................................... 18

Figure 10: Telephone Direct Shield Connection............................................................................... 19

Figure 11: Telephone Direct Pair Connection.................................................................................. 20

Figure 12: Receiver Controls and Indicators..................................................................................... 21

Figure 13: Locating the Cable or Pipe............................................................................................... 24

Figure 14: Determine Cable Path in Peak Mode............................................................................... 24

Figure 15: Depth Measurements 45° Angle Method......................................................................... 29

Figure 16: Signal Return through an Insulation Fault to Earth.......................................................... 31

Figure 17: Collapsible Ground Return Probe................................................................................... 32

Figure 18: Ground Return Probe Insertion....................................................................................... 33

Figure 19: Spoked Wheel Return Paths............................................................................................ 33

Figure 20: Ground Return Probe Fault Locating.............................................................................. 34

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Introduction

Receiving Instructions

Check the equipment received against the packing list to ensure that all materials
are present. Notify Megger of any shortage. Telephone [phone] and ask for
the customer service department.

Examine the instrument for damage received in transit. If damage is discovered,
file a claim with the carrier at once. Prepare a detailed description of the damage
and notify Megger.

This instrument has been thoroughly tested and inspected to meet rigid
specifications before being shipped. It is ready for use when set up as indicated
in this manual.

General Information

Thanks for purchasing the Megger L1070 or L1071 Portable Locator. The
portable locator will help you locate and trace the routes of buried power cables,
cable television cables, gas and water pipes, sewer lines, telephone cables, and
fiber-optic cables. When used with the accessory ground return probes, the
portable locator will pinpoint faults on most direct buried secondary cables and
some direct buried primary cables.

The transmitter transmits a special signal on the cable under test. The receiver
receives the signal and indicates how strong it is. Microprocessors in both units
process the information and allow you to determine the path of the underground
cable.

Supplied Components

1. Receiver unit

AVTM651070 Rev B Nov 2006

2. Transmitter unit

3. Red/black test cord

4. Instruction Manual AVTM651070

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Options

5. Eight 1.5 V D-size batteries (for L1070 non-rechargeable transmitter only)

6. Six 1.5 V C-size batteries

7. Ground rod

8. Ac battery charger (for L1071 rechargeable transmitter only)

9. Carrying case

1. Ground return probe

2. Carrying case for the ground return probe

3. Flexible coupler

4. Dc battery charger (automotive)

Preparation for Use

Remove the receiver from the case. Locate the battery compartment. Install the
six 1.5-V C-size batteries as marked on the battery holder. Install the battery
cover and tighten the retaining screw.

Remove the transmitter from the case. Locate the battery compartment on the
bottom of the transmitter. Remove two screws from the battery compartment
door. Install the eight D-size batteries as marked on the battery holder. Install the
battery cover and tighten the two retaining screws.

2

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Safety

Precautions

The L1070 and L1071 Portable Locators and the recommended operating
procedures have been designed with careful attention to safety; however, it is not
possible to eliminate all hazards from electrical test equipment or to foresee
every possible hazard that may occur. It is therefore essential that the user, in
addition to following the safety rules in this manual, also carefully consider all
safety aspects of the test before proceeding. Safety is the responsibility of the
user.

F

Use suitable barriers, barricades, and warnings to keep people not actually
engaged in the test at a safe distance. Make sure that no one can make contact
with energized parts of the test equipment and the specimen under test.

Treat all terminals of power equipment as a potential electric shock hazard.
There is always the possibility of voltages being induced at these terminals
because of proximity to energized high-voltage lines or equipment.

Always turn the transmitter power off before touching any terminals.

Always disconnect test leads from the cable under test before attempting to
disconnect them from the portable locator.

Never connect the test leads to a cable that does not have a safety ground strap
in place. Never disconnect the test leads from a cable that does not have a safety
ground strap in place. The safety ground connection must be the first made and
the last removed. Any interruption of the grounding connection can create an
electric shock hazard.

WARNING!

Do NOT connect to live or energized power cable.

Observe all safety warnings marked on the equipment. These warnings identify
areas of immediate hazard which could result in personal injury or loss of life.

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Do not operate the equipment with protective covers removed. Operation
without the protective covers presents an electric shock hazard.

Use all practical safety precautions to prevent contact with energized parts of the
equipment and related circuits.

Use the recommended grounding and connection procedures. Make sure that the
equipment is grounded properly. Any interruption of the grounding connection
can create an electric shock hazard.

Refer to IEEE 510-1983 "IEEE Recommended Practices for Safety in High­Voltage and High-Power Testing" for additional information.

Do not use the portable locator or its accessories with any device or for any
purpose other than as specifically described in this manual. Misuse of this
equipment can be extremely dangerous.

Never connect the portable locator to energized equipment.

Do not use in an explosive atmosphere.

The L1071 Portable Locator uses rechargeable batteries. Replace only with sealed
lead-acid batteries as specified in Section 3, Specifications. Danger of explosion
can result if the wrong batteries are used.

If the portable locator is operated in accordance with the safety precautions
described, and if all grounds are correctly made, rubber gloves are not necessary.
As a routine safety procedure, however, some users require that rubber gloves be
worn, not only when making connections to the high-voltage terminals but also
when manipulating controls. Megger considers this an excellent safety practice.

Warning and Caution Notices

Warning and caution notices are used throughout this manual where applicable.
These notices appear in the format shown below and are defined as follows:

Warning, as used in this manual, is defined as a condition or

F

practice which could result in personal injury or loss of life.

WARNING!

G

CAUTION
Caution, as used in this manual, is defined as a condition or
practice which could result in damage to or destruction of the
equipment or apparatus under test.

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3

Specifications

Receiver

Operating frequency: 82 kHz, 8 kHz, 815 Hz , 50/60 Hz (PASSIVE)

Antenna mode: Null-responding vertical coil

Peak-responding horizontal coil

Audio indication: Variable pitch response on all frequencies.

Current measurement

Operating & storage
temperature range

Battery type: Six 1.5 V, C-size alkaline

Battery life: Continuous: 40 hr

Dimensions: 30.3 x 3.7 x 9.4 in. (76.9 x 9.3 x 23.8 cm) (L x W x H)

Weight: 3 lb (1.36 kg)

Signal strength:

Gain control: Up/down button for automatic centering and manual control.

Dynamic range: 126 dB

Display indicated relative current simultaneously between any two
selected cables for tar get cable verification in a multi-conductor

environment.

-4°F to 133°F (-20°C to +55°C)

Intermittent: 82 hr (automatic shutoff after 10 min of nonuse)

Analog LCD bar graph. Absolute Digital Signal Strength readout
from 0 to 999.

Depth measurement
Automatic:

AVTM651070 Rev B Nov 2006

Push-button, three-digit readout to 15 ft (4.6 m) in feet-inches.
(optional m-cm)

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Transmitter

Operating frequency: 82 kHz, 8 kHz, 815 Hz and BOTH (815Hz/82kHz)

AC LOAD RESISTANCE MEASUREMENT.LOW BAT
Low battery warning modulated or output signal every 20 seconds.

Load matching

Output power: Normal High

815 Hz 0.6 W 2.0 W
8 kHz 0.6W 2.0 W
82 kHz 0.2 W 1.0 W
BOTH 0.12 W+.06 W 1.33 W+0.67 W
Battery type:

1070 Disposable - Eight 1.5 V, D-size alkaline

1071 Rechargeable - One 12 V, 7 Ah maintenance-free, sealed lead -acid

Battery life:

Disposable

Continuous 8 to 15 hr depending on load, frequency & power setting

Intermittent

Automatic from 5 to 2000 Ω

40 to 60 hr depending on load, frequency & power setting. 25%
duty cycle average

Rechargeable

Continuous 10 to 20 hr depending on load, frequency & power setting.

Intermittent

Operating and stora ge
temperature range:

Dimensions: 16 x 6.32 x (5-6) in. (40.6 x 16 x (12.7-15.2) cm) (L x W x H)

Weight: 8 lb (3.6 kg) with disposable alkaline cells

50 to 70 hr depending on load, frequency & power setting. 25%
duty cycle average.

-4°F to +133°F (-20°C to +55°C).

11.5 lb (5.2 kg) with rechargeable sealed lead-acid cells

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SPECIFICATIONS

Battery Charger

Ac battery charger (included with L1071 Portable Locator) charges battery overnight

Input: 120 V ac

Output: 12 V dc @ 500 mA

Output cord: 6 ft (1.82 m) with 2.5 mm x 5.5 mm female power connector

Dc battery charger (available as an option with the L1071 Portable Locator)

Charge rate:

Automatic cut-off: 14.1 V

Input:

Input cord: 4 ft (1.2 m) with vehicle cigarette lighter adapter plug with 3 A, fast-blo fuse

Output cord: 12 ft (3.6 m) with 2.5 mm x 5.5 mm coaxial power plug

Dimensions: 4.25 x 3 x 1.75 in. max (L x W x D)

Observe the following precautions when using the dc battery charger.

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1.0 ±10% A

10/15 V dc  negative ground

CAUTION
Not recommended for batteries with less than 2.5 Ah capacity.
Do not use on damaged or shorted batteries.
Allow for air circulation around charger case. Do not cover.
Do not use if circuit is exposed to moisture.

Disconnect immediately if batteries get hot.

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OUTPUT

BREAKER

OUTPUT

OUTPUT

CONTROL

RECHARGER

SIGNAL

TRANSMITTER

BATTERIES NEED

OUTPUT

4

Transmitter Operation

Controls and Indicators (Fig. 1)

Follow all safety precautions in Section 2 of this manual.

JACK

CIRCUIT

CIRCUIT
IMPEDANCE

REPLACEMENT
OR CHARGING

OUTPUT
JACK

SIGNAL

ON INDICATOR

Figure 1: Transmitter Controls and Indicators

OUTPUT CIRCUIT BREAKER

FREQUENCY
CONTROL

AVTM651070 Rev B Nov 2006

The circuit breaker is tripped if the TRANSMITTER is
subjected to a voltage of 250V or 1.5 amps.

TX OUTPUT (SIGNAL OUTPUT JACK)

The TX OUTPUT is the jack. The RED/BLACK CORD and
the FLEXICOUPLER connects to create a circuit on the

buried utility.

WARNING: LETHAL VOLTAGE MAY BE PRESENT

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POWER OUTPUT CONTROL

The POWER OUTPUT selects Low or High power output
from the po wer transmitter.

LOADING Indicator

The LOADING indicator flashes to indicate the output circuit
impedance. When the indicator blinks 4 times per second, it
is indicating a nearly short circuit. When the indicator blinks
1 time every 3 seconds, it is indicating a nearly open circuit.

LOW BAT Indicator

When the LOW BAT indicator is on, it is time to change the
batteries in the TRANSMITTER. The output will cycle every
20 seconds to indicate a low battery condition.

TX ON

The TX ON indicates the TRANSMITTER is on.

FREQUENCY CONTROL

The FREQUENCY CONTROL cycles through the output
frequencies. The LED’s next to the frequency label indicate
which frequency is in use. When the LED’s next to the
815Hz and 82kHz labels are on at the same time the unit is
simultaneously transmitting both frequencies. When the
LED’s repeatedly cycle through all of the frequencies the
unit is in Fault Finding mode.

Ac Resistance Indications

The LOADING indicator on the transmitter panel blinks as follows to indicate
output circuit resistance. If the LOADING indicator does not blink in the AF
mode, plug in the red/black cord.

NO. OF BLINKS

4 blinks per sec

2 blinks per sec

CIRCUIT RESISTANCE Ω

5 to 15 Ω circuit

15 to 100 Ω circuit

1 blink per sec

1 blink every 2 sec

1 blink every 3 sec

100 to 400 Ω circuit

400 to 1800 Ω circuit

1800 Ω to open circuit

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TRANSMITTER OPERATION

Transmitter Rechargeable Battery Option

If your transmitter has an optional rechargeable battery, the battery cover will
extend past the main transmitter housing shell approximately 1/2 in. (1.27 cm).
The recharger jack is situated near the carrying handle on the transmitter
housing. To replace the sealed, rechargeable 12 V, 7 Ah lead-acid battery, remove
the back cover and four nuts on each side of the battery bracket. Remove the
battery, then remove the red wire and the black wire from the battery terminals
by pulling off the spade connectors.

An automatic shutdown circuit protects the lead-acid battery from discharging
below the safe level of 8.2 V. Reset the automatic shutdown circuit by turning
the POWER OUTPUT switch OFF. When the battery voltage is discharged
down to 10.5 V, the LOW BAT icon on the LCD is activated. From the time the
LOW BAT icon is activated, you will have between 15 and 30 min of operating
time before automatic shutdown occurs. Also, when the LOW BAT icon is
activated, the transmitter output signal will cycle every 20 sec.

Recharging the Battery/External Power Pack

CAUTION
Set the transmitter POWER OUTPUT switch to OFF before you

G

Using the ac charger: A fully discharged battery can be fully charged in less

Using the dc charger: A fully discharged battery can be fully charged in less

begin recharging.

than 24 hr using the ac charger. A partially
discharged battery requires less recharging time. Use
your judgment to decide on a reasonable recharge
time. Overcharging shortens battery life.

than 5 hr using the automotive 12-V dc charger.
Typically, every 10 min of charge will give you about
20 min of battery usage. Although it is possible to
power the transmitter with the automotive charger,
the charger will not supply enough energy to charge
the battery at the same time.

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Selecting the Locating Method

Identify the application below that matches your job, and then select the locating
method. Although the first method listed under each heading will produce results
with the simplest connections, we recommend that you use direct connection
whenever possible.

WARNING

F

After selecting the locating method, turn to the page that tells you how to
connect the equipment. For the most reliable locate, we recommended that you
use low power and low frequency, whenever possible. Refer to the Specifications
section for output power information.

POWER CABLE AND CABLE TV

§ Multiple Grounded Circuit

§ Flexible Coupler Connection

§ Inductive Connection

§ Direct Connection

§ Passive 50/60 Hz Locating

GAS AND WATER PIPE

Never connect the test set to energized equipment.

§ Continuously Grounded Circuit

§ Flexible Coupler Connection

§ Passive 50/60 Hz Locating

TELEPHONE CABLE

§ Multiple Grounded Circuit

§ Telephone Direct Shield Connection

§ Telephone Direct Pair Connection

AVTM651070 Rev B Nov 2006

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§ Passive 50/60 Hz Locating

FIBER-OPTIC CABLES

§ Multiple Grounded Telco Circuit

§ Inductive Connection

§ Telephone Direct Shield Connection

§ Passive 50/60 Hz Locating

NOTE: The output will cycle when the LOW BAT indicator is activated to

inform you that a LOW BAT condition is present. You must use the
82 kHz high frequency setting when using the inductive connection
method.

Power Utility Connection

TRANSMITTER OPERATION

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This method, which has a range of up to 0.5 mi (0.8 km), uses the ground points
that are already exposed and available to you. Make connections as shown in
Figures 2 and 3. Because you are only transmitting the signal on the grounding
system, it is not necessary to disconnect the service.

CAUTION
Turn the transmitter off before connecting or disconnecting

the red and black test leads.

Figure 2: Multiple Grounded Circuit Connection

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Figure 3: Multiple Ground Power Utility Application

Telco Circuit Connection

Figure 4: Multiple Ground Telco Application

Connect the red test cord to an existing ground point. Place the ground rod
approximately 10 ft (3 m) from this point, at an angle of 90° to the buried cable
or pipe. Drive the ground rod into the ground 8 to 10 in. (20.3 to 25.4 cm).

Connect the black test cord to the ground rod.

Plug the red/black test cord into the TX OUTPUT jack. Set the FREQUENCY
switch to AF. The TX ON indicator will start blinking.

Turn to the Receiver Operation section to begin locating the cable or pipe.

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Flexible Coupler Connection

You do not have to interrupt service when you use the flexible coupler, but the
operating range is somewhat reduced. Also, more of the tracing signal may leak
to neighboring cables and pipes than in the direct connection method.

Ensure that the cable under test is insulated and grounded at both ends. Connect
the flexible coupler as shown in Figure 5.

TRANSMITTER OPERATION

Figure 5: Flexible Coupler Connect ion

Start by looping the flexible coupler around the cable and connecting the two
ends. It is important to connect the flexible coupler around the cable you want to
trace, as shown in Figure 5. Remember that when you connect the flexible
coupler around the entire cable including the ground conductor that is common
to other cables, you will sacrifice some of the benefits you get when using the
direct connection method. The transmitted signal in the cable under test will be
weaker, the range will be shorter, and you may have trouble telling one cable
from another.

Plug the flexible coupler test cord into the TX OUTPUT jack. Set the
FREQUENCY switch to RF. The LOADING indicator will start blinking.

Turn to the Receiver Operation section to begin locating the pipe or cable.

NOTE: Set the switch on the flexible coupler test cord plug to the desired locate

frequency. Then set the transmitter FREQUENCY switch to the
desired frequency.

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Inductive Connection

This method is convenient because it does not require interruption of service.
No test leads are needed. When the cable or pipe has no insulation or
nonconductive coating, the operating range will be very short.

Place the transmitter on the ground as close as possible to the path of the cable
or pipe. Align the arrows on the transmitter control panel at a small angle to the
cable or pipe. Set the FREQUENCY switch to RF. When you turn the
transmitter on, the LOADING indicator will start blinking. First locate the broad
transmitter null then, move toward the expected cable path while looking for the
signal carried by the cable.

Start tracing the path by placing the receiver at least 25 ft (7.6 m) away from the
transmitter. Search in the 90° zone as shown in Figure 6. Locate the cable or
pipe, and follow the path. When the signal received by the receiver becomes too

weak after progressing along the route, move the transmitter to a location no
closer than 25 ft (7.6 m) behind the receiver and continue tracing. Note that the
transmitter may produce its own null when the receiver is within 25 ft (7.6 m) of
the transmitter. When you cannot avoid locating the receiver closer than 25 ft
(7.6 m) from the transmitter, place the transmitter at a 30° angle over the target
conductor. (See Fig. 7). In this example, two nulls will be present, one transmitter
null and one cable/conductor null.

Turn to the Receiver Operation section to begin locating the cable or pipe.

Figure 6: Inductive Connection

Figure 7: Inductive Connection 30° Angle

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Direct Connection

The direct-connection locating method shown in Figure 8

F

requires service interruption, and therefore must only be
performed by authorized service technicians.

TRANSMITTER OPERATION

WARNING

Figure 8: Direct Connection

Direct connection is the most reliable method available. It is less subject to
interference, and an additional ground rod is not needed. The range of operation
is up to 15 mi (24 km).

Disconnect the cable shield or neutral wire. Connect the red test cord to the
cable shield or neutral wire. Connect the black test cord to the system ground,
where the cable shield or neutral wire had been connected.

Plug the red/black test cord into the TX OUTPUT jack. Set the FREQUENCY
switch to AF. Turn the POWER OUTPUT switch to ON. The LOADING
indicator light will start blinking.

Notes on Selecting the Tracing Signal

The choice of 815 Hz, 8 kHz or 82 kHz Frequency is dependent on the
conditions of the locate.

The 815 Hz, 8 kHz and 82 kHz signals each have their advantages. It is
recommended to begin by using the 815 Hz signal, and continue as long as you
are confident in the results. If the signal is very weak try to adjust the connection
or grounding. If there is no improvement in signal then try 8 kHz. Repeat
adjustments of ground and connection point again until switching to 82 kHz.

815 Hz (lower frequency) signal is usually preferred to the 8 kHz (mid-range
frequency) and 82 kHz (high frequency) signal, because it is much less
susceptible to locating errors caused by nearby cables or pipes. The 815 Hz
locating range is also much longer than the 82 kHz signal. The 815 Hz signal will
not travel well through disconnected shield bonds or insulated pipe bushing.

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Continuously Grounded Circuit

8 kHz takes the best of both high and low frequency. This mid range frequency
is not very susceptible to bleed off or coupling, but it can jump impedance on
the utility better than the 815 Hz. It is still best to use 815 Hz, but 8 kHz is one
of the most common frequencies used to locate coaxial cable and telecom pairs.

The 82 kHz (higher frequency) is sometimes better than the 815 Hz (lower
frequency) for locating sharp corners in cables or pipes. The 82 kHz signal is also
better for jumping” disconnected shield bonds or grounds, or tracing signal may
indicate one of these characteristics. The locating range is quite short for the 82
kHz signal so the TRANSMITTER must be repositioned more often during the
tracing operation. This FREQUENCY is also useful for applying a signal using
the FLEXICOUPLER OR THE HARD COUPLER..

The locating range for bare uninsulated cable and pipe is typically 300 ft (91.4 m).
If the locating range on a particular pipe seems unusually short, there may be an
insulating bushing in the buried pipe. Try to bypass the insulated bushing by
connecting the transmitter to a location on the pipe that is past the bushing.

For pipe - connect the red test lead to the shutoff valve wrench surface or union
fittings near the gas or water meter. For cable - connect the red test lead to any
point on the bare neutral. See Figure 9.

Place a ground rod approximately 10 ft (3 m) from this point, along a line that is
perpendicular to the buried pipe or cable. Insert the ground rod 8 to 10 in. (20.3
to 25.4 cm) into the ground. Connect the black test cord to the ground rod.

Plug the red/black test cord into the TX OUTPUT jack. Set the FREQUENCY
switch to AF. The LOADING indicator light will start blinking after the
transmitter is turned on.

Turn to the Receiver Operation section to begin locating the cable or pipe.

Figure 9: Continuously Grounded Circuit

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Telephone Direct Shield Connection

TRANSMITTER

TELEPHONE CABLE

We recommend this method for telephone service because there is usually a
ground lug available for making connections, and damage to the cable is unlikely.
This method provides reliability, and you do not have to interrupt service.
However, all connections must be made by either an authorized telephone
company employee or an authorized locator contractor. Readings may be
confusing if several cable shields are bonded together.

Disconnect the shield from the system ground. Connect the red test cord to the
cable shield. Connect the black test cord to the telephone pedestal or previous
shield attachment point. See Figure 10.

Plug the red/black test cord into the TX OUTPUT jack. Set the FREQUENCY
switch to AF. The LOADING indicator will start blinking when the transmitter
is turned on.

Turn to the Receiver Operation section to begin locating the cable or pipe.

TRANSMITTER OPERATION

BLACK

RED

PEDESTAL

RYCOM

GROUND

ROD

BURIED

Figure 10: Telephone Direct Shield Connection

Telephone Direct Pair Connection

NOTE: This method will not work with a floating ground ESS #5.

Because service is disconnected during the tracing operation, this method
requires that either a telephone company employee or other authorized
contractor make the connections. You can expect to obtain highest quality
results, which more than justifies the extra preparation time and effort.

Connect the red test cord to one of the wire pairs in the cable you want to trace.
Do not use insulation piercing clips. Connect the black test cord to the system
ground at any convenient point. See Figure 11.

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Plug the red/black test cord into the TX OUTPUT. Set the FREQUENCY
switch to AF. The LOADING indicator will start blinking when the transmitter
is turned on. Proceed to locate with the receiver toward the central office.

Turn to Receiver Operation section to begin locating the cable or pipe.

Figure 11: Telephone Direct Pair Connection

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DISPLAYS ABSOLUTE

FINDING MODE

FREQUENCY

RELATIVE

SIGNAL STRENGTH

SELECTS LINE OR

ON/OFF BUTTON

SELECTS FREQUENCY

BUBBLE LEVEL

SELECTS PEAK OR NULL

ADJUSTS GAIN UP AND DOWN

MODE

INDICATES BATTERIES

SELECTS VOLUME

USED WITH OTHER

MEASURES TRANSMITTED

5

Receiver Operation

Controls and Indicators

Figure 12 shows the controls and indicators on the receiver.

(for 45 degree depth)

SIGNAL STRENGTH,
DEPTH AND FAULT

IINDICATOR

BAR GRAPH
(single bar shows gain setting)

SONDE DEPTH MODES

MEASURES DEPTH

(with SHIFT key selects
either English or metric depth
measurement)

INDICATOR

NEED TO BE REPLACED

(Off, Low, Medium or High)

Note: Hidden function.
Using SHIFT, select PINPOINT or
NORMAL PEAKING MODE

BUTTONS TO SELECT
ADVANCED FEATURES

SIGNAL FLOW IN CONDUCTOR
(Using SHIFT key for turning on

and off BACKLIGHT)

OR SETS OPTIMUM GAIN WHEN
SIGNAL IS OFF BARGRAPH SCALE

AVTM651070 Rev B Nov 2006

Figure 12: Receiver Controls and Indicators

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ON OFF

Press the ON OFF button to turn the RECEIVER on (if
currently off) or off (if cur rently on). Upon turning the unit
on, it will load the settings from the previous usage. Upon
turning the unit off, the settings will be saved within the unit
to be recalled next time the unit is used.

Note: Unit will automatically shut off if no keys are pressed

within a 10 minute period.

FREQUENCY

Press the FREQ button to switch the RECEIVER
frequency from 82 kHz, 8 kHz, 815 Hz, 50/60 Hz and Fault
Finding Mode. With each press of the key, it will toggle

through the different frequencies in order.

+

DEPTH

Pressing the DEPTH button will cause the RECEIVER to
first display the mode of the depth (Line or Sonde) and
then the depth will be measured. To change the Depth
Measurement from English to Metric, hold SHIFT and
press FREQUENCY. To change LINE and SONDE use

the LINE/SONDE key.

GAIN Button (Up or Down)

Used to adjust the gain level for the receiver. When the
GAIN button is pressed, the RECEIVER will adjust the
gain up or down. If the signal strength shows as “ --- ” on
the display and a GAIN up or down key is pressed, the unit

will automatically adjust to 90 on the scale display.

SHIFT with the FREQUENCY (ENGLISH/METRIC)

Press the SHIFT and the FREQUENCY buttons to toggle
the units for display of the device. When pressed it will
toggle between English and Metric units. When in Metric
the display will show - cm - in the top of the display. When
in English, the display will show - ’ “ - in the top of the

display.

LINE/SONDE

Press to toggle the depth mode from Line to Sonde
modes. When in Line mode the display will show LIN in the
top of the display. When in Sonde mode the display will
show SON in the top display.

AVTM651070 Rev B Nov 2006

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+

RECEIVER OPERATION

CURRENT

Press the CURRENT button to measure the amount of
current that is flowing while in the 815 Hz, 8 kHz or 82 kHz

frequency modes.
Note: The CURRENT button will not work when in the

50/60 Hz frequency modes.

MODE

Press the MODE button to set the receiver to PEAK and
NULL locating mode. Hold SHIFT and press MODE to
select PINPOINT Peak Mode or NORMAL Peak Mode.
PIN will appear in the display to indicate PINPOINT and
NOR will appear in the display to indicate NORMAL.

REFIND PEAKING MODE

The L1070/L1071 has a hidden function. To activate PIN
Peaking Mo de hold the SHIFT key and press MODE key.
“Pin” will appear at the top of the display. Repeat the
process to switch back to NORMAL Peaking Mode. “nor”
will appear at the top of the display. The unit resets to

NORMAL when turn ed off.

VOLUME

Press VOLUME button to toggle the volume of the device

+

from High, Medium, Low and Off. When this key combo is
pressed, the volume level will be toggled through the four

volume levels in order.

BACKLIGHT

Hold the SHIFT Key and press the CURRENT key to
toggle on and off the backlight.

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Locating Cable or Pipe

Figure 13: Locating the Cable or Pipe

Make sure that the transmitter is solidly connected to the cable or pipe and
turned on. Move about 15 ft (4.6 m) away from the transmitter along the path.
For the inductive search method, move about 25 ft (7.6 m). Hold the receiver so
that you can see the LCD bar graph and controls easily. Make sure the receiver
and transmitter frequencies are both set for the same frequency. Press the
MODE button to select the desired Peak or Null locating mode.

Peak Mode Locating

Figure 14: Determine Cable Path in Peak Mode

Keep the receiver approximately vertical. While you are walking along the path
of the target cable or pipe, with the receiver in the Peak mode, gently swing the
receiver across the path. When the receiver is directly above the cable or pipe, all
indicators will be at a maximum. You might occasionally rotate the receiver
slightly to confirm that you receive a maximum signal when you are directly over
and in line with the target cable (see Fig. 13). As you swing the receiver away
from the cable path, the digital strength readout, the relative strength bar graph,
and audio frequency response will all drop off. If you rotate the receiver about

AVTM651070 Rev B Nov 2006

24

RECEIVER OPERATION

90° while over the cable, a sharp null will identify the cable direction, which will
be aligned with the flat side of the receiver.

Trace the path by observing the peak indications while walking away from the
transmitter at a moderate pace.

As you trace the path in a direction away from the transmitter, the Peak meter
reading will slowly fade. Press and release the GAIN buttons as needed to
compensate for losses in Peak signal level. If the Peak meter reading suddenly
changes in level (higher or lower), you may have found one of the following:

1. A junction where the signal divides (lower)

2. A break in the cable or shield (lower)

3. A change in depth of the cable or pipe (higher or lower)

4. An insulated pipe fitting (lower)

5. A slack loop of cable (lower)

If you can no longer trace the path, even with the gain set to maximum, connect
the transmitter to the far end of the cable, and trace back to the point where you
lost the signal.

Mark straight sections of the path every few feet. Mark sharp curves, loops, and
cable bundles every few inches. Sharp changes in the path cause the receiver
Peak and Null indications to behave differently than when tracing a straight path.
Practice on a path that you know has turns and laterals in it, so you will recognize
these conditions in the field.

Null Mode Locating

When in the Null mode, gently swing the receiver across the cable path as you
would when in the Peak mode. However, in the Null mode, all indicators will be
at a minimum when the receiver is directly above the cable or pipe. When the
receiver is only a small distance to the left or to the right of the target cable, all
indicators will be at a maximum. When the receiver is farther away to the left or
right of the cable, all indicators will begin to fade.

Trace the path by walking away from the transmitter at a moderate pace. Gently
swing the receiver left and right as you walk, following the Null indications.

AVTM651070 Rev B Nov 2006

As you move away from the transmitter, the maximum meter readings may
slowly fade as was described for the Peak mode. If the maximum meter reading
suddenly changes in level (higher or lower), you may have found one of the
following:

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1. A junction where the signal divides (lower)

2. A break in the cable or shield (lower)

3. A change in depth of the cable or pipe (higher or lower)

4. An insulated pipe fitting (lower)

5. A slack loop of cable (lower)

If you can no longer trace the path, even with the gain set to maximum, connect
the transmitter to the far end of the cable, and trace back to the point where you
lost the signal.

Mark straight sections of the path every few feet. Mark sharp curves, loops, and
cable bundles every few inches. Sharp changes in the path cause the receiver
Peak and Null indications to behave differently than when tracing a straight path.
Practice on a path that you know has turns and laterals in it, so you will recognize
these conditions in the field.

Absolute Signal Strength

The receiver provides a direct measurement of the received signal strength. This
measurement is displayed continuously at the top of a three-digit LCD, in a range
from 0 to 999 indicating a very weak signal to a very strong signal, respectively.
As the receiver nears the buried cable, the numbers increase. As the receiver
moves away from the buried cable, the numbers decrease. These numbers
indicating signal strength are sometimes referred to as Signal Power Indicators or
SPI numbers.

Although signal strength is independent of the gain setting, the gain setting will
have an effect. If the gain is adjusted too far above mid-scale, the signal strength
indicator will blank out. You will know you have adjusted the gain low enough
when the signal strength display reappears.

NOTE: Do not confuse Signal Strength with Signal Strength Adjusted for

Depth (Current Measurement). Signal Strength gives the operator a
measurement of how much signal is actually being received from the
conductor. For a given amount of current on the target cable, you will
measure a higher signal power when the cable is close than when the cable
is farther away. Signal Strength Adjusted for Depth takes the depth of
the conductor into consideration. As the depth of the conductor changes,
Signal Strength Adjusted for Depth measurements will remain the same.
Signal Strength Adjusted for Depth is actually giving the operator an
indication of the amount of signal current through the conductor.

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AVTM651070 Rev B Nov 2006

RECEIVER OPERATION

Signal Strength Adjusted for Depth (Current Measurement)

The receiver contains a feature that is very useful in identifying a target cable (the
cable that is connected to the transmitter) in a field of various conductors and/or
utilities. It is not unusual for the target cable to induce or to leak the transmitted
signal into nearby conductors through a common ground system. Consequently,
you can receive a stronger signal from nearby conductors close to the surface of
the earth than the signal from the target conductor buried deeper. You will find
two or more paths and you must somehow determine which is the target
conductor. By using the current measurement feature of the receiver, you can
determine the amount of transmitted AF or RF current flowing on each
conductor. The highest current flow always indicates the target conductor.

To measure the current flow in each cable in the congested area, locate the path
of the cables. Mark these paths as accurately as possible (Refer to the sections on
Peak Mode Locating and Null Mode Locating). Place the receiver vertically over
one of the conductor paths and rest the foot of the locator on the ground. While
holding the receiver vertically, press and release the CURR button. When the
meter changes from a thermometer-type display to a bar-type display, hold the
receiver steady until the measurement stabilizes. The blinking bar indicates the
current level on the cable, adjusted for depth. Next, move to the second cable
and repeat the measurement. Again, the blinking bar will show the current level
on the cable. To help you remember the previous reading, it is shown as a solid
bar. The higher of the two readings will represent the target cable.

NOTE: If the display reads “Err” during a current measurement, the receiver

has detected a condition that could produce inaccurate readings. Errors
can result when conductor signal current flow is too low. Check the
transmitter hookup and the far end access point for loose connections.
This problem can be identified when you need a high gain setting (80 or
greater on the bar-graph display).

The receiver may also be detecting adjacent cables or it may not be
positioned directly over the target conductor. Verify that the target
conductor path is accurate before measuring the current again. If at
anytime the display reads “CAL,” contact the factory for further
information.

AVTM651070 Rev B Nov 2006

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Gain Change Indication

Passive 50/60 Hz Locating

Use the GAIN up and down buttons to increase and decrease the gain in small
steps to center the meter reading to mid-scale.

The receiver is capable of locating loaded underground primary and secondary
utility cables. It can also locate underground water pipes, sewer lines, and other
metallic lines such as cable television lines, and telephone lines that are
accidentally carrying some utility current. The transmitter is not needed to locate
in this mode.

Press the FREQ button to select the 50/60~ (Hz) frequency on the receiver.
Press the MODE button to select the Peak Mode. Locate the conductor by using
the receiver as previously described for Peak Mode Locating. Passive locating can
be faster because of its convenience. Start at a known reference point and keep
in mind that other conductors in the area may produce this same locating signal.

Push-Button Digital Depth

The only way to be sure of depth of a utility is to expose the utility.

At any time, the depth readout may be inaccurate. Depth measurement, 45­degree angle method, should be used to verify push button depth measurements.

You need only push a button on the receiver to measure depth. Depth is
displayed digitally at the top of the display window in feet and inches (or meters
and centimeters, factory selected).

First locate the path of the cable. Then move to the location where you want to
measure depth. Do not measure depth closer than 15 ft (4.6 m) from the
transmitter. Pinpoint this location as accurately as possible. (Refer to the sections
on Peak Mode Locating, Null Mode Locating, and Absolute Signal Strength).
With the foot of the locator resting on the ground, hold the receiver vertically
over the conductor. Press and release the DEPTH button. The receiver will
briefly indicate that a depth measurement is being calculated, and then it will
display the depth.

Note that offset magnetic fields and interfering adjacent conductors can
significantly influence depth measurements. You should periodically check for
adjacent conductors and offset magnetic fields when you make depth
measurements. For information on identifying offset magnetic fields, refer to the
following sections on Depth Measurement 45° Angle Method and Offset

Magnetic Field Identification.

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AVTM651070 Rev B Nov 2006

NOTE: If the display reads “Err” during a depth measurement, the receiver has

detected a condition that could produce inaccurate readings. Be especially
alert to errors that are caused by inadequate signal current flow. Check
the transmitter hookup and far end ground return access point for loose
connections. Suspect a low current problem when you have to set the gain
to 80 or greater on the bar-graph display. Check to be sure the receiver is
directly over the target cable. If at anytime the display reads “CAL,”
contact the factory for further information.

Depth Measurement 45° Angle Method

As a correlation to the depth measurement by push-button method, you can
measure depth using a triangulation method as shown in Figure 15. This
alternative method will also help you determine whether or not there are
interfering nearby cables.

Move to the spot where you want to measure depth and pinpoint and mark the
path of the cable. Then place the foot of the receiver on the ground with the
meter facing up. Adjust the position of the unit until the bubble level on top of
the meter is centered at 45°. Pull the receiver away from the cable path along a
line that is perpendicular to the cable. When the locator indicates a null reading,
mark the location of the foot of the receiver. Measure the distance between the
receiver and the cable path. This distance is the same as the depth of the target
cable or pipe.

RECEIVER OPERATION

AVTM651070 Rev B Nov 2006

You can check for a possible false depth reading caused by nearby buried
metallic objects such as another cable or pipe, sewer line, fence, or railroad track.
To confirm your depth measurement, repeat the above steps on the opposite
side of the pipe or cable. A difference of more than 5 in.(12.7 cm) in the two
depth measurements can mean that there are interfering cables, pipes, or other
objects, and that the accuracy of the depth measurement is less than usual.

Figure 15: Depth Measurements 45° Angle Method

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Offset Magnetic Field Identification

When adjacent cables or pipes are present in the right of way, they will
sometimes create locating errors. Some of the transmitted signal is picked up by
nearby conductors or pipes and reradiated so that it adds to or subtracts from the
original signal. The result is an offset magnetic field that can cause path locating
errors.

You can verify the presence of this problem by using triangulation to measure
depth, as described in the preceding section on Depth Measurement 45° Angle
Method. If the right side and the left side depth readings agree to within about 5
in. (12.7 cm), your path locate is fairly accurate. If the two depth readings do not
agree, your path locate is not accurate. You can decrease the error by marking the
path as being about halfway between the two outside depth locate marks. This
important strategy can be used to obtain the most dependable path location
possible. See Figure 15.

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AVTM651070 Rev B Nov 2006

6

Fault Locating with the L1070/L1071

Introduction

Fault locating determines the position of an insulated break on an underground
conductor. In the case of an insulation fault, some of the signal will return to the
TRANSMITTER attached to the GROUND ROD through a break in the
insulation.

Figure 16: Signal Return through an Insulation Fault to Earth

Signal Return through an Insulated Fault

It is generally a good idea to locate the conductor path before attempting to fault
locate. If, during the path locate, an unusual amount of signal loss occurs, a part
of the signal has escaped to ground in the last several feet.

Note: Signal would go to ground at a grounded splice point, which would act as

a fault during the path and fault locate.

Once the path is determined and there is a general area where a fault is expected,
additional current can be forced to flow through the fault by disconnecting and
isolating the far access point. If the current has no path to ground at the far
access point, it will be forced to seek ground at the fault. This will increase the
current in the soil at the fault and detection of the fault.

AVTM651070 Rev B Nov 2006

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Setting the Transmitter to Fault Mode

Setting the Receiver to Fault Mode

Ground Return Probe

After the path is determined and the far access point is disconnected and
isolated, the transmitter must be set to fault mode. This is accomplished by
pressing the FREQUENCY button toggling through the frequencies until all
LED indicators light up and flash. The transmitter is now transmitting the fault
locating signal.

To set the RECEIVER to fault mode, press the FREQUENCY button toggling
through the frequencies until F F flashes at the top of the display above the bar­graph. The transmitter is now ready to be attached to the GROUND RETURN PROBE.

To begin fault locating, open the GROUND RETURN PROBE (GRP) and
attach the unit RECEIVER as shown below. Plug the GROUND RETURN
PROBE CORD into the GRP handle with the straight connection. The
GROUND RETURN PROBE is collapsible for easy transport and storage.

G

USE CAUTION WHEN OPENING AND CLOSING THE GRP

Figure 17: Collapsible Ground Return Probe

AVTM651070 Rev B Nov 2006

32

Ground Return Probe Insertion

Circuitry between the ground spikes provides a path for current in the soil
returning to the GROUND ROD. The current enters one spike of the
GROUND RETURN PROBE and exits the other spike. The GRP should be
inserted into the soil with consistent force and depth.

Figure 18: Ground Return Probe Insertion

FAULT LOCATING

The current in the soil spreads out from the fault like the spokes of a wheel. The
current is highly concentrated in the soil near the fault as it begins its return, and
near the GROUND ROD as it finishes its return. Notice that the current is
widely dispersed in the soil between the fault and the GROUND ROD.

Figure 19: Spoked Wheel Return Paths

Ground Return Probe Fault Locating

AVTM651070 Rev B Nov 2006

When the GROUND RETURN PROBE is inserted into the soil the direction to
the fault is indicated on the RECEIVER’S display. Bars flashing at the top of the
graph indicate the fault is away from the transmitter and access point. Bars
flashing on the bottom of the graph indicate the fault is toward the transmitter
and access point. When the bars center on the graph the a-frame is over the fault.

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NOTE: The bars may not always flash at the center of the graph. In this case the

faults location is determined by the immediate change in fault direction
when the GROUND RETURN PROBE is move slightly in either direction.

As you walk the path using the GRP, drop the probe every three or four steps.
Once the signal indicator on the RECEIVER changes directions, you should
move back taking smaller steps, covering smaller segments of ground to avoid
passing the fault. The fault lies in the center of the GROUND RETURN
PROBE spikes. Finally change the orientation of the GRP 90 degrees and move
the GRP both forward and backward, re-centering the graph. This will ensure an
accurate location of the fault.

Figure 20: Ground Return Probe Fault Locating

34

AVTM651070 Rev B Nov 2006

7

Service

Maintenance

The portable locator is a rugged, durable instrument built to withstand the rigors
of day-to-day field use. It requires no periodic adjustments or calibration. It is
however an electronic instrument and should be treated as such.

§ When not in use, keep the portable locator in its carrying case and store in a

safe, dry place, away from extremes in weather conditions.

Repair

§ Should the unit become dirty, wipe it down with a damp cloth. Do not use

cleaning compounds on the transmitter or receiver.

§ Periodically inspect the test cord to ensure that it is in good condition.

If your portable locator is not working properly, please call:
1-800-723-2861 ext. 8578 or 610-676-8500 ext. 8578 for return authorization and
shipping instructions.

AVTM651070 Rev B Nov 2006

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AVTM651070 Rev B Nov 2006