Aqua-Tronics EG 3000 User manual
INSTRUCTION MANUAL
EG 3000 | EG 3000T
To Locate All Unshielded Cable Faults and
Sheath-to-Ground Faults
Plus:
• Cable Tracing
-Direct
-Inductive
-Inductive Coupler
U.S. Patents #4,697,137
and #4,233,561
EG 3000
Earth Gradient
Cable Fault
Locator
EG 3000 T
Includes
Cable Locating
with Automatic
Impedance
Matching
1
WHEN TO USE EARTH GRADIENT FAULT LOCATING
Earth gradient techniques can only be used on "unshielded, insulated” cables and can only
locate a "short" or "nonlinear" fault.
A short occurs when direct metallic contact has been made between two or more conductors, such
voltage will collapse. This causes the fuse or breaker to blow. The fault resistance will measure
less than a few ohms.
A nonlinear fault occurs where the cable has an insulation failure. An arc will form at the fault at
some voltage level equal to, or less than, the normal operating voltage of that cable. The fault
resistance can measure several thousand ohms. This same fault can change to almost a dead
short at the correct operating voltage, or the cable might still be in service with some lower-than
normal voltage present. In other words, the cable fault is leaking current to ground, but the fault
resistance is high enough to keep from blowing a fuse or breaker.
EARTH GRADIENT FAULT LOCATING PROCESS
To begin the locating process, the faulted cable is isolated at both ends and then a pulsed voltage
the fault to ground, fault currents travel from the fault back to the transmitter ground rod. These
fault currents set up a "voltage gradient’. in the earth that can be measured.
indicator. The input to the detector comes from two probes that are pushed into the ground, which
pick up the voltage gradient present.
The detector and the probes are moved down the route of the faulted cable. The input probes are
set some distance apart, much like the chain used in football to mark yardage. The input probe
opposite input probe is now closer to the fault. When the two probes are at an equal distance
on each side of the fault, the direction indicator will remain at center, or in a “NULL” position.
spread out over a wide area as it travels from the point of fault to the ground rod, so the detector
may see a reduced amount of signal in the area between the fault and the ground rod. In other
words, the operator will see a large indicator pulse on the detector near the ground rod. As the
is more pronounced if the fault is a long distance from where the transmitter is connected to the
cable or if the ground cover is asphalt or concrete.
2
As the probes are moved along the
route of the cable, readings should
be taken every few feet. Being in
a hurry and moving the probes
too far between readings allows
the operator to leap past the fault
especially true in very dry sand or
over asphalt or concrete. Until the
operator becomes an experienced
fault locator, he should move the
lead probe 5 to 10 feet down the
route of the cable. The back or
trailing probe, should be placed
where the lead probe was before it was moved. Once the fault is located, further readings
should be taken some 10 to 20 feet past to verify that the operator has indeed gone past the
fault. A reverse pulse on the indicator should be present. (See Figure 1)
DESCRIPTION OF THE EG 3000
The transmitter produces a negative square wave pulse into the faulted cable. This pulse will be
At 3000 volts the transmitter produces 10 milliamps; at 300 volts the transmitter produces
200 milliamps.
The voltage control allows the operator to adjust the transmitter output to the voltage level
the fault, the transmitter automatically takes control of the output voltage control and reduces
its voltage to the lowest level required to keep the fault alive. The output voltage level required
if the ground conditions change, the transmitter
output will track the fault resistance and keep
enough voltage at the fault to keep the fault alive.
Into a one ohm fault, the transmitter will produce
approximately 2.2 volts, or just over 2 amps of fault
current. This high current produces a good, strong
gradient field, and the low voltage protects low
voltage cables from voltage stress.
Black Coil Cord
Red Coil Cord
Ground Rod
ISOLATED CABLE
EG 3000
B B BR R R
Black Probe = ( - ) on detector
Red Probe = ( + ) on detector
Cable Fault
At “NULL” mark halfway
between Red & Black Probe
Figure 1
+ \ -+ | -+ / -
CAUTION: Always use rubber
gloves when operating the
EG 3000. Between 300 and
3000 volts can be present on
the transmitter output.
3
The fault resistance can change during the fault locating process. For example, soil can dry out
and raise the fault resistance level because of the fault current present from the transmitter, or
rain can moisten the soil and reduce the fault resistance level. Regardless of the conditions,
the transmitter automatically tracks the fault resistance and apples only the voltage needed to
keep the fault alive. However, if the fault resistance increases beyond the original voltage level
higher. In other words, the voltage control sets the upper limit of the transmitter output voltage.
The transmitter’s automatic voltage tracking and adjustment functions work only below this limit.
conditions where the operator wants to know when the transmitter is pulsing, turning the horn
switch to “ON” will pulse the horn every time the transmitter pulses.
The output meter on the transmitter is used for several functions.
1. To tell the operator when the fault “breaks over". from the voltage applied by the
transmitter, allowing the fault to be located. When the fault breaks over and sets up a
the detector should not begin until the meter pulses. If the meter does not pulse when
starts to pulse.
2. To proof test the cable (to see if the transmitter is connected to a good cable that is not
faulted). This is useful after the repair has been made, or to make sure that the transmitter
is not connected to a good cable in error. If the transmitter meter tries to pulse backwards
at a voltage control setting of 1500 to 1700 volts, the cable is not faulted. The cable has
been repaired, or the transmitter is not connected to the faulted cable.
This transmitter can be connected to a live 120 volt circuit (120 volts maximum), which can lead
to three problems.
1. Never actuate any switch or control when the output is connected to a live 120 volt
circuit. If a switch contact makes or breaks with voltage present, the contact will draw an
arc. This arc can create a voltage spike of over 500 volts, which is large enough to
damage the instrument under some conditions.
Place the function control switch to TONE TRACE, or FAULT LOCATE before the output
connection is made. If the function switch is in TONE TRACE position, also turn the
transmitter on and set the Auto / Manual Tap select switch to Manual Tap # 2 on the Tap
Selector Display before any output connection is made.
2. If the transmitter is in the fault locate mode and is connected to a live 120 volt circuit,
meter registers a constant reading of any type, the cable is not isolated and voltage
of some type is present on the cable. A fault locate can be made, but do not change any of the
transmitter control settings if the transmitter function meter has a constant reading of any type.
4
The transmitter meter will pulse even though
the fault may not be breaking over. The
neutral ground rod will be seen through the
transformer windings and this will provide a
conductive path to the soil. These earth
currents will be received by the transmitter
and will cause the transmitter meter to
pulse.
If the transmitter is connected to a cable
that is not isolated at both ends, the voltage
control should be set at 3000 volts to insure
the fault will break over. When the fault
breaks over, the voltage will automatically
reduce to a low level and fault currents will
automatically increase. This will not damage
the cable or transformer.
3. If connected into a live 120 volt circuit, a
high 60 Hz current can be entering the ground
detector direction indicator to oscillate under some conditions.
If the detector direction indicator starts to oscillate or produce erratic readings that cannot
be corrected with the balance control, stop the fault locate and isolate the cable. A high
60 Hz current can prevent the detector from responding to the transmitter’s fault current.
00
When the Fault Locate-Tone Trace function switch is in the TONE TRACE position, the Fault
for fault locating to be used for placing a tone on the cable for cable tracing. Even if the cable
location and route can be described, the operator should always use a good cable locator and
trace out the actual route of the cable to be tested. If the operator is not following the correct
route of the faulted cable, a lot of time and energy can be spent without much success.
The transmitter is powered by two methods:
1. 120 volt line (60 Hz) 110/230 universal input 90 - 264
2. Internal rechargeable 12 volt battery
A good rule of thumb is to charge at least two hours for each hour of operation. A Red LED on the
face of the transmitter front panel indicates when the battery is being charged from a 120 volt wall
outlet and will remain on until disconnected from the outlet. The Green LED will turn on when the
battery is fully charged. A 3/4 amp slow blow fuse is also used in the power supply from the AC 120
volt line cord. If the battery cannot be charged from the AC line cord, this fuse should be checked.
Note: The meter is not useful for
measuring actual fault resistance.
Claims made to the contrary for any
such instrument overlook one item. The
resistance of the earth is also involved.
The output circuit is from the transmitter
output, through the cable, through
the fault, and through the earth back
to the ground rod and back into the
transmitter. This total circuit is the total
resistance and each component can
vary. In other words, instruments using
a meter to measure fault resistance
tell the operator only ,what the total
loop resistance is, which includes but
is unlikely to represent, the actual fault
resistance.
5
1. Never use this instrument without using rubber gloves. 3000 volts at 10 milliamps will get
your attention, but 300 volts at 200 milliamp could create a serious problem. The only way
to make sure the operator is safe is to never violate a safety rule. Rubber gloves are
required for safe operation.
2. Install a safety zone with signs, tape, rope, cones, and any other warning tools available
to ensure no one can enter the area. Small children, adults, and animals have been
injured because a proper safety zone was not installed to keep them out of the area.
The price we pay for safe working conditions is very small compared to the price we pay
when we overlook it.
3. Locate the cable under test with a good cable locator and mark the route. See the back
section of this manual for cable locating.
4. Establish a good solid ground for the transmitter or much time can be lost in the actual
fault locating process. Do not move the ground probe while the transmitter is on.
CONNECTING THE EG 3000 TO THE FAULTED CABLE
1. After the route of the cable to be worked is located and marked, isolate the cable at both
ends. If the cable is on a tap feed, make sure that each meter being fed from this cable
is pulled. Also check and make sure any and all street lights are disconnected. Street
lights are some times tap fed from a transformer to house cable. The cable is not ready
to fault locate until ALL ends are isolated.
2. Connect the black high-voltage coil cord from the transmitter to the ground rod. -
3. Connect the red high-voltage coil cord from the transmitter to the faulted cable.
4. Choose the method of operation: AC Line, or the internal battery.
5. Make sure the Tone Trace / Fault Locate Function Switch is set to Fault Locate. If the
transmitter does not have tone tracing abilities, this switch is not present and the
transmitter is always in the fault locating mode.
6. Turn on the transmitter.
7. Setting the transmitter to 3000 volts will do two things to help in making a fault locate.
a. It will proof test the cable. If connected to a good cable at 3000 volts, the transmitter
meter will try to pulse backward.
help when locating a fault in dry soil or under asphalt or concrete.
Note: When connecting the output cable
assembly to the transmitter, care should be
used to avoid rotation/twisting of parts B & C.
The locknut, Part A can be rotated to tighten the
H.V. cord to the transmitter.
*The H.V. output cable assembly IS NOT A LIFTING POINT!*
6
WHEN A GOOD EARTH GROUND IS NEEDED
If the cable is properly isolated at both ends, the fault location can be started from either
end in most cases. System ground or neutral can be used instead of the ground rod in the
earth, but this can also create problems in the fault locate. Whenever possible, the ground
rod should be used and positioned as far away from the system ground rod as possible.
Some fault locates may require the neutral to be removed from the system ground rod.
ground rod would then look like a ghost fault.
cable as possible. Never place the ground rod over the route of the cable under test.
If the ground rod is placed over the route of the faulted cable, and the fault is either
near the rod or between the rod and the transmitter, the fault can be hidden by ground
currents between it and the ground rod. If the ground rod can be placed on the opposite
side of the connection from the route of the cable, even those faults within a few feet of
the cable connection can be found in a very short time.
ANALOG DETECTOR
When the transmitter is operating and the transmitter
scale, the EG 3000 Detector is walked down the route of
the cable. The two probes can be used, or the operator
can use a fixed distance between the probe rods by
accessory to the instrument. If the soil is very dry or the
operator is a long distance from the fault, a dead spot
may be found where the detector will not pick up any
pulse. As the detector nears the fault, the pulse can be
detected and will increase in strength the closer to the
fault the detector gets. The Direction to Fault Indicator
provides direction to the fault from where the operator
is standing.
The sensitivity control adjusts the amount of signal
being fed to the meter. Lower sensitivity levels are better
to use and easier to work with. This will also help reduce
any meter backlash present on the Direction to Fault
Indicator.
Placing the two probes farther apart can also help in the
dead area of no signal. Fault currents are present, but
they are spread out, and the weak or reduced amount
of fault current creates the dead spot. By placing the
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pulse that may go undetected if the two probes are close together.
To set the Balance Control, turn the detector on with the probes in the ground and the cord
plugged in to the detector. Turn the Sensitivity control to full scale and set the Balance Control for
a “0” center on the Direction Indicator. The Sensitivity Control can then be adjusted to the level
needed to perform the locate. The Balance Control Should Not be adjusted again on that locate.
The battery compartment located on the side of the detector uses one # 216 9-volt battery or
equivalent (NEDA #1604).
CONNECTING THE DETECTOR FOR USE
Plug the detector cable assembly into the jack on the
top side of the detector. The two small cable clips should
be connected to the hole in the foot probes behind the
attached handle.
The voltage being picked up by the probe is very small
and could not hurt anyone, unless the probe tip was
in contact with a high voltage source (electric fence,
a live cable in the ground, or the cable fault when the
The detector is worn around the neck with a neck strap.
The face of the direction indicator has a battery test mark
on the right hand side of center.
The upper portion of the analog meter face has a (+) Red
on the right and a (-) Black on the left. The (+) Red on the
analog meter is the red wire probe input and the (-) Black
on the analog meter is the black wire probe. The operator
should carry the red wire probe in the right hand and the
black wire probe in the left hand during fault location.
Insert the two probes into the ground and let go of them. Turn the sensitivity control up or down
so that the directional indicator is getting a small kick in the (+) or (-) direction. If the two probes
are over the route of the cable, the direction the indicator kicked is the direction the fault will be
from that point. In other words, if the indicator kicks to the (+) Red side on the meter. the red
wire probe is closer to the fault than that of the (-) Black wire probe.
If the operator is near the ground rod being used, a large kick may be found. The kick could be
a large one if the probes are far apart, or if the sensitivity is turned up to some high setting. The
ground rod being used is the collector of fault currents making their way back to the transmitter,
thus, the concentration of fault current could appear strong enough to indicate you are near the
fault when you are not. As you move down the cable route away from the transmitter, the fault
direction indication could reduce to a very small kick. It could die out to where you are not picking
up direction indicator kick even at full gain. This means the fault is some distance from this point,
and the fault currents are spread out over a large area on their way back to the ground rod. The
fault currents may have collected on some conductor in the area like a water pipe near
the ground rod. In theory, the fault current should travel from the fault to the ground rod in a
straight line. This is not always the case when other utilities are in the area.
If this were always true, the operator could rotate around the cable ground rod until he found the
strongest direction indicator kick. He could then travel in that direction until the fault is found. In
some cases this would work, but the rule of thumb will always be to follow the route of the cable.
Sooner or later, serious problems will arise by taking the easy way out.
Separating the probes will help produce larger readings. Move down the route of the cable and
insert the probes into the ground every 5 to 10 feet. As you approach the fault, the detector will
start receiving larger and larger pulses with the same sensitivity setting. If the direction Indicator
for a clear indicator reading. Shortening up the distance between the two probes will also reduce
When you start your fault locating, the red or black probe can be toward the fault. Regardless
of which probe is toward the fault, you should keep that probe as the lead probe. Proceed down
the route of the cable in a "football chain' like method. At some point, the direction indicator
will kick in the reverse direction, or toward the opposite probe. You have now passed the fault.
Move back, to the point where this reversal took place and place one probe on each side of the
suspected position of the fault. If the indicator is kicking toward the red probe, move the black
probe a few inches at a time toward the red probe. At some point, the pulse, or direction indicator
will start reducing. When the indicator starts kicking toward the black probe, this will indicate
is found (a null point), and the movement of either probe will provide a direction indicator, the
fault will be half way between the two probes, if the probes are over the route of the cable.
(See Figure 2)
Black Coil Cord
Red Coil Cord
Ground Rod
ISOLATED CABLE
EG 3000
B B BR R R
Black Probe = ( - ) on detector
Red Probe = ( + ) on detector
Cable Fault
At “NULL” mark halfway
between Red & Black Probe
Figure 2
+ \ -+ | -+ / -
9
Place one of the probes directly over the point marked as the fault (center). Move the other probe
around all four sides of the center probe, keeping the probe being rotated an equal distance
from the center probe at each of the four side locations. If the Indicator always kicks toward the
center probe, you have located the fault.
If on one side of the center probe, the indicator kicks in the opposite direction, this means the probe
the two probes in the direction of the indicator kick until the indicator again kicks in the reverse
indicator will always kick toward the center probe, the center probe will be directly over the fault.
(See Figure 3)
What was thought to
be route of cable
Actual route of
isolated cable
Actual Cable Fault
Thought to be
point of fault
Rotate one probe on all 4 sides of center
probe postion over suspected point of fault
At position 1, 2, & 3 indicator pulsed toward
red wire probe, indicating fault to be under
red wire probe. Position 4, pulsed toward
black wire probe indicating the location
was even with, but not over the fault.
Move in direction of indicator pulse to locate
position of fault. Directional Indicator will
always pulse toward center probe if center
probe is over the fault.
STEP 1 -
STEP 2 -
4
4
3
3
2
2
1
1
Figure 3
B R
+ / -
B R
10
HELPFUL LOCATING TECHNIQUES
A problem some people have experienced operating the EG 3000 detector occurs when they
can slow the locating process, because stray currents can be seen that did not come from the
fault. This problem has occurred, we have found, because operators were used to other brands
of detectors with less sensitive systems.
Use only enough gain to see the pulse. At 5 or 6 on the sensitivity scale and below, we have
the same gain as Brand X, Y, & Z and our detector is very stable. The only time you can use
the high portion of the sensitivity control is if the probes can be inserted in the ground and the
operator removes their hands from the probes. Even a small movement caused by wind to the
metal-to-earth contact can produce an Indicator reading
In some ground conditions, it is not possible to insert the probes into the ground. Rock,
cement, or asphalt can be a problem. In this condition, do not use the two probes. The two cable
clips can be clipped to two household sponges that are soaked in water (approximate size 4 x
truck should have as a back-up tool.
With the two cable clips connected to the wet sponges, move the sponges down the route of the
cable under test. If it is not possible to use the two wet sponges, soaking the area with a garden
hose can provide good results with the two probes. Two large copper plates (approximately 6 x
6 inches each) could also be used, if water cannot be applied to the area. Nails driven through
the road cover is another method often used. Touching the two probe tips to nails that are driven
into the road cover will most often produce the results needed to locate a fault.
If the transmitter is connected to a meter riser, and the fault is at the riser, locating the fault can
be a problem. The fault current leaving the cable at the point of fault is so close to the ground rod
detector. If you suspect the fault to be near the transmitter or ground rod, move the transmitter
to the other end of the cable. You will not want the ground rod anywhere near the fault to be
located. As mentioned earlier, the ground rod is the collector of fault currents for the transmitter
and this concentration of fault currents, if placed near the point of fault, can obscure detection
of the desired fault current. Much time can be wasted trying to read through the large mass of
currents the detector sees if the ground rod is nearby.
When you have any fault in a position (like a meter riser) where the probes cannot be set on
each side of the fault, draw a half circle around the area of location. (See Figure 4 on page 11).
Notice that if the probes are rotated until a ‘NULL” is found, an imaginary line drawn through the
center spacing of the two probes is aimed at the fault. The lines through several NULL points all
converge on the same spot which is the fault location.
11
Half Circle drawn arounnd
area of fault
Isolated Cable
Imaginary Line through center
of detector process at Null point
BUILDING
Meter
Riser
Cable
Fault Imaginary line through center
of detector probes at Null point
will point at fault
Figure 4
B R
+ | -
B
B
R
R
+ | -
+ | -
FEATURES AND ADVANTAGES OF THE EG 3000
• The EG 3000 detector has as much gain as any detector on the market.
Aluminum hydroxide and copper sulfate are both insulators. When moisture comes in contact
with aluminum or copper, this oxide forms and what was a low impedance fault can become
a very large resistance. This resistance allows a leakage path to earth, and a low voltage can
result on the line because current is going to ground.
the high voltage limits of their instrument and gradient current is low.
12
break down the fault, you know it is a high impedance fault and a little more voltage is needed.
The operator gradually turns up the voltage control while watching the meter on the face of the
the transmitter will automatically reduce itself to the lowest voltage needed to keep the fault alive,
and the meter on the transmitter will pulse.
has control of what the instrument is doing. In this way a low voltage cable will never have a
voltage that is higher than needed to complete the fault locating job. Stressing low voltage
cables with a high voltage and high current at the same time is of some concern to all utilities.
create as many problems as you solve.
CABLE LOCATING
Make sure the EG 3000 is turned "OFF" before any connections are made.
Connect the large cable clip with the black coil cord to a good solid earth ground. A 19" ground
probe supplied with the instrument can be used. Connect the Red clip to the cable under test.
(Pouring water on the ground rod in dry soil can improve a cable trace.)
1. The FAULT LOCATE - TONE TRACE switch should be set to TONE TRACE.
2. The AUTO - MANUAL - TAP SELECT switch should be set to AUTO.
3. The tone trace power switch should be set to LOW.
4. Turn on the transmitter.
The transmitter will go through a self test on the numerical display window. This will take
several seconds. When the self-test is complete, the automatic impedance matching will set
the transmitter to the correct output tap and this number will then be displayed. The line is now
ready to be traced.
WARNING: A switch contact making or breaking 120 volts can arc
and this will produce a high voltage transient spike of 500 volts or
more. This high voltage spike can reect back into the transmitter
and create problems. Thus, the transmitter should be placed in
manual/mode, TAP#2 before a direct connection is made on a live
120-volt circuit.
13
NULL TRACING METHOD
A high signal reading is found on both sides of the conductor, and a loss of signal is found
directly over the conductor. The sensitivity control setting will determine how sharp or broad
the null will be.
With the transmitter connected to the conductor and turned on, move out away from the
transmitter 5 to 10 feet. Push the NULL/ PEAK button, between the handle and the meter, to
NULL. Turn on the receiver by rotating the sensitivity control knob under the handle grip from the
the transmitter in the direction the meter starts to increase. When a location is found where the
meter drops to "0" and an increase in signal is found on both sides of the "0" location, this will
be a locate to mark. When two positions or NULLS have been found, the operator knows the
direction of the run.
THE OPERATOR CANNOT SEE THE LOWEST READING IF THE METER IS AT A "0"
READING. IF THE NULL IS BROAD, INCREASE THE SENSITIVITY CONTROL UNTIL A
SHARP NULL IS FOUND. IF THE NULL IS SO SHARP THAT THE METER DOES NOT HAVE
TIME TO RESPOND, THE OPERATOR COULD WALK OVER THE LOCATE AND NOT SEE
THE NULL; HOWEVER, A SMALL LOSS OF TONE MIGHT BE HEARD. THE SENSITIVITY
SHOULD BE REDUCED TO WHERE A SHARP NULL CAN BE SEEN ON THE METER.
Figure 5
14
Now that two null points have been found, the route of the conductor can be walked by moving
the receiver back and forth over the line being traced. NEVER SWING THE LOCATOR. The
receiver should be moved back and forth over the line being traced with the bottom of the
antenna area remaining approximately the same distance from the ground at all times.
MAXIMUM OR PEAK TRACING METHOD
A maximum meter reading will be found directly over the line being located and with
the receiver antenna at right angles to the conductor's path, the meter will decrease
to lesser readings as the instrument moves away from either side. When the locator
is directly over the line and at right angles to the line, the locate has been made. IN THE
PEAK METHOD, THE RECEIVER PROVIDES THE DIRECTION OF THE LINE BEING
TRACED FROM ONE LOCATING POINT. THE LINE BEING LOCATED WILL BE AT RIGHT
ANGLES TO THE RECEIVER. In other word, if the operator would lay an arrow on top
of the receiver handle with the shaft crossing #5 on the meter dial, the arrow head would
be pointing down the route of the locate. Unlike the null mode that can be made with the
receiver pointing at any axis of a compass, the peak mode cannot. In the peak mode, no
reading can be taken if the instrument is parallel to the. direction of the conductor run.
See Figure 6
Figure 6
Note: If you obtain a wide
or broad peak reading from
the receiver when locating
your cable near the
transmitter see “Correcting
a wide or broad peak
reading on a cable trace.”
See page 18.
15
LOCATING BY THE MAXIMUM OR PEAK METHOD
With the transmitter connected and operating, move out 5 or10 feet from the transmitter. Turn
on the receiver and push the NULL/PEAK button to the PEAK position. Adjust the sensitivity
control for a mid scale meter reading. Walk a half circle around the transmitter in the direction the
to where the meter movement can be seen increasing or decreasing. Meter movements cannot
be seen if the meter movement is at "0" or at "10".
When a location has been made, the meter will show its highest point directly over the spot
to be marked and the receiver is at right angles to the line being located. A movement of the
receiver to the right or left side of this highest meter reading will produce a meter reading that
is decreasing from the high point.
Now that the conductor has been located, turn the sensitivity down to a very small meter
movement above "0" on the meter dial when the antenna is directly over and at right angles to
the line being located. Keep moving the instrument from one side of the peak reading to the
other. Each time a peak reading is found, the ire will be directly below the center of the receiving
antenna. Do not swing the antenna from side to side.
*Note: More detailed instructions of the Digi-7 Receiver can be found by visiting:
www.aquatronics.com/links/pdfs/DIGI7_Manual.pdf, or scan the code below:
More detailed instructions or the A-700 Receiver can be found by visiting:
www.aquatronics.com/links/pdfs/A700_Manual.pdf, or scan the code below:
The receiver will always power up in the AUTOMATIC PEAK MODE OF OPERATION. Turn on
the receiver and rotate the large knob until the desired level of sound is being heard. In the Auto
the lower left corner of the LCD display will point to NULL.
Move 5 to 10 feet from the transmitter and walk a half circle around the transmitter until the
bar-graph display starts to increase. At some point, the bar-graph will drop to a small value and
then increase. Directional arrows are also present and will indicate what direction is needed
16
arrow will change, and the sound being heard will also change. The numerical signal strength
meter will read 'Absolute signal' and it will be at a maximum even though the receiver is in the
NULL mode of operation. In the Automatic NULL Mode, the receiver will provide direction to
the conductor with LEFT/RIGHT arrows on the display so the receiver must be at right angles
to the conductor path.
Locating in the manual mode allows the operator to take control of the receiver sensitivity. The
large knob that was the loudness control in Auto Mode is now the sensitivity control.
point to the word NULL on the lower left corner of the LCD display. In the upper left corner, a
numerical read out will appear. This 0-100 reading will indicate the position of the sensitivity
control. The manual mode will operate the same as the A-700 analog receiver.
When the receiver is turned on, it will power up in the Automatic Peak Mode. The volume
control knob can be adjusted for sound desired.
Move 5 to 10 feet from the transmitter and walk a half circle. Record all of the peak signals
found in the half circle and notice the absolute signal display number at each peak signal
found. Depending on the Depth, the strongest signal may not be the utility being traced, but
the strongest signal is a good starting point. When a location has been made, the bar-graph
and absolute signal reading will both provide the highest value. A down arrow will replace the
LEFT/RIGHT guidance arrows directly over the located cable. No audio output will be present.
Moving the receiver from side to side will produce the directional arrows and tone change
each time the receiver passes over the conductor.
Locating a peak in the manual mode is the same as the A-700 Receiver. No LEFT/RIGHT
guidance arrows are present, and the loudness control becomes a sensitivity control. Sensitivity
percentage will be displayed in the upper left corner of the LCD display. The tone will no longer
change pitch as the receiver passes from one side of the conductor to the other.
17
The Inductive Coupler can only
be used on a cable or conductor
that is grounded at both ends.
This ground can be through a low
impedance load of some type such
as a transformer or appliance. The
soil is the signal return path on a
closed loop and if the cable is not
grounded the circuit loop is open
A street light in the day time could
not be traced with an Inductive
Coupler because the photo-cell
is open. At night when the photo-
cell is closed, the cable could be
traced with Inductive Coupler. A
jumper cable and a screw driver
could be used on a cable to
ground one or more ends. A secondary service can be located even if the meter is pulled
because the neutral will still be in place, provided the cable is still grounded at the transformer
and at the meter base.
The Inductive Coupler is plugged into the EG 3000 T transmitter into the inductive output phone
jack. The TONE TRACE TAP SELECTOR SWITCH should be set to TAP#1. This will set the
impedance of the transmitter to the impedance of the Inductive Coupler for the best trace.
On primary cables, the Inductive Coupler should always be placed around the neutral or over
neutral and cable. The Inductive coupler should never be used on the elbow side of the neutral
break away point. On a direct buried 3-phase cable, place the Inductive coupler around all three
cables. If it is placed around one cable, very poor results will be obtained because all three
cables are grounded to each other along the cable route. (See Figure 7)
When using the Inductive Coupler or the Direct Output mode of tracing, there may be times when
a wide or broad peak reading is found near the transmitter. If this occurs, the receiver is being
by setting the transmitter Auto-Manual-Tap Select switch to Manual. The tap select switch will
allow the direct output impedance to be set at number 4 or 5 in the numerical display window.
the receiver and a sharp crisp reading can be found near the transmitter.
The tone trace power control just to the right of the tap switch should be set to low. For greater
tracing range and deep locations, a higher power level may be required, but most locations can
be made with a low setting.
CAUTION: ALWAYS
USE RUBBER GLOVES
WHEN INSTALLING AN
INDUCTIVE COUPLER
ON PRIMARY CABLES.
This manual suits for next models
1
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