RIDGID ST-305 SeekTech Line Transmitter User Manual

Original Instructions – English – 1

Operator’s Manual

SeekTech ST-305

Record product serial number below as it appears on the nameplate.

Serial

No.

WARNING!

Read this Operator’s Manu-

al carefully before using this

tool. Failure to understand

and follow the contents of

this manual may result in

electrical shock, fire and/or

serious personal injury.

SeekTech ST-305

5 Watt Pipe and Cable Line Transmitter

SeekTech ST-305

2 – English

SeekTech ST-305

Table of Contents

Recording Form for Machine Serial Number �� 1

Safety Symbols �� 3

General Safety Rules �� 3

Work Area Safety �� 3

Electrical Safety �� 3

Personal Safety��3

Equipment Use and Care ��3

Battery Precautions��4

Service ��4

Specific Safety Information ��4

ST-305 Safety ��4

Description, Specifications and Standard Equipment ��5

Components ��5

Installing/Changing Batteries ��6

Sounds of the ST-305 ��6

Powering ON / OFF ��6

Machine Inspection �� 7

Set-Up �� 7

Select a Frequency on the Transmitter�� 7

Check the Circuit and Adjust Power Level �� 7

Check the Receiver ��8

Operation ��8

Useful Operating Tips ��8

Direct-Connect Method ��8

Dual-Frequency Transmission ��9

Inductive Clamp Method �� 9

High Voltage Indicator ��11

Useful Information �� 11

Resistance and Impedance ��11

Using High and Low Frequencies ��11

Cleaning ��12

Storage ��12

Service and Repair ��12

Disposal ��12

Battery Disposal ��12

Troubleshooting ��13

English – 3

SeekTech ST-305

General Safety Rules

WARNING

Read all safety warnings and instructions. Failure to fol-

low the warnings and instructions may result in electric

shock, re, and/or serious injury.

SAVE THESE INSTRUCTIONS!

Work Area Safety

• Keep your work area clean and well lit� Cluttered or dark

areas invite accidents�

• Do not operate equipment in explosive atmospheres,

such as in the presence of flammable liquids, gases, or

dust� Equipment can create sparks which may ignite the

dust or fumes�

• Keep children and bystanders away while operating

equipment� Distractions can cause you to lose control�

• Avoid traffic� Pay close attention to moving vehicles when

using on or near roadways� Wear visible clothing or reflec-

tor vests�

Electrical Safety

• Avoid body contact with earthed or grounded surfac-

es such as pipes, radiators, ranges, and refrigerators�

There is an increased risk of electrical shock if your body is

earthed or grounded�

• Do not expose equipment to rain or wet conditions�

Water entering equipment will increase the risk of electri-

cal shock�

• Do not abuse the cord� Never use the cord for carrying,

pulling, or unplugging the power tool� Keep cord away from

heat, oil, sharp edges, and moving parts� Damaged or en-

tangled cords increase the risk of electric shock�

• If operating equipment in a damp location is unavoid-

able, use a ground fault circuit interrupter protected

supply to reduce the risk of electric shock�

• Keep all electrical connections dry and off the ground�

Do not touch equipment or plugs with wet hands to reduce

the risk of electrical shock�

Personal Safety

• Stay alert, watch what you are doing, and use common

sense when operating equipment� Do not use equipment

while you are tired or under the influence of drugs, alco-

hol, or medication� A moment of inattention while operating

equipment may result in serious personal injury�

• Use personal protective equipment� Always wear eye

protection� The appropriate use of protective equipment

such as a dust mask, non-skid safety shoes, a hard hat,

and hearing protection will reduce personal injuries�

• Do not overreach� Keep proper footing and balance at all

times� This enables better control of the equipment in unex-

pected situations�

• Dress properly� Do not wear loose clothing or jewelry�

Keep your hair, clothing, and gloves away from moving

parts� Loose clothes, jewelry, and long hair can be caught

in moving parts�

Equipment Use and Care

• Do not force equipment� Use the correct equipment for

your application� The correct equipment will do the job

better and safer at the rate for which it is designed�

• Do not use equipment if the power switch does not turn

it ON and OFF� Any equipment that cannot be controlled

with the power switch is dangerous and must be repaired�

• Disconnect the plug from the power source and/or the

battery pack from the equipment before making ad-

justments, changing accessories, or storing� Preventive

safety measures reduce the risk of injury�

• Store idle equipment out of the reach of children and

do not allow persons unfamiliar with the equipment or

Safety Symbols

In this operator’s manual and on the product, safety symbols and signal words are used to communicate important safety

information� This section is provided to improve understanding of these signal words and symbols�

This is the safety alert symbol� It is used to alert you to potential personal injury hazards� Obey all safety messages that follow

this symbol to avoid possible injury or death�

DANGER

DANGER indicates a hazardous situation which, if not avoided, will result in death or serious injury�

WARNING

WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury�

CAUTION

CAUTION indicates a hazardous situation which, if not avoided, could result in minor or moderate injury�

NOTICE

NOTICE indicates information that relates to the protection of property�

This symbol means read the operator’s manual carefully before using the equipment� The operator’s manual contains important

information on the safe and proper operation of the equipment�

This symbol means always wear safety glasses with side shields or goggles when handling or using this equipment to reduce

the risk of eye injury�

This symbol indicates the risk of electrical shock�

Store idle equipment out of the reach of children and do not allow persons unfamiliar with the equipment

or these instructions to operate the equipment. Equipment can be dangerous in the

hands of untrained users.

4 – English

SeekTech ST-305

these instructions to operate the equipment� Equipment

can be dangerous in the hands of untrained users�

• Maintain equipment� Check for misalignment or binding

of moving parts, missing parts, breakage of parts, and any

other condition that may affect the equipment’s operation� If

damaged, have the equipment repaired before use� Many

accidents are caused by poorly maintained equipment�

• Use the equipment and accessories in accordance

with these instructions; taking into account the work-

ing conditions and the work to be performed� Use of

the equipment for operations different from those intended

could result in a hazardous situation�

• Use only accessories that are recommended by the

manufacturer for your equipment� Accessories that may

be suitable for one piece of equipment may become haz-

ardous when used with other equipment�

• Keep handles dry, clean, and free from oil and grease�

This allows for better control of the equipment�

Battery Precautions

• Use only the size and type of battery specified� Do not

mix cell types (e�g� do not use alkaline with rechargeable)�

Do not use partly discharged and fully charged cells togeth-

er (e�g� do not mix old and new)�

• Recharge batteries with charging units specified by

the battery manufacturer� Using an improper charger can

overheat and rupture the battery�

Service

Ensure a qualified repair person services your equipment

using only identical replacement parts to maintain the safety

of the tool� Remove the batteries and refer servicing to quali-

fied service personnel under any of the following conditions:

• If liquid has been spilled or objects have fallen into product�

• If the product does not operate normally when following

the operating instructions�

• If the product has been dropped or damaged�

• When the product exhibits a distinct change in perfor-

mance�

Specic Safety Information

WARNING

This section contains important safety information that

is specic to the SeekTech ST-305. Read these precau-

tions carefully before using the SeekTech ST-305 to re-

duce the risk of electrical shock, re, or other serious

personal injury.

SAVE ALL WARNINGS AND INSTRUCTIONS

FOR FUTURE REFERENCE!

Keep this manual with the equipment for use by the operator�

ST-305 Safety

• The SeekTech ST-305 is intended for use with a Seek-

Tech locator/receiver� The locator is a diagnostic tool that

senses electromagnetic fields emitted by objects under-

ground�

• Use equipment only as directed� Do not use the transmit-

ter and related equipment unless proper training has been

completed and the operator’s manual or instructions read�

• ALWAYS HOOK UP LEADS FIRST BEFORE POWERING

THE UNIT ON TO AVOID SHOCK� ALWAYS TURN UNIT

OFF BEFORE DISCONNECTING LEADS� ELECTRIC

SHOCK MAY RESULT FROM FAILURE TO CONNECT

LEADS BEFORE POWERING THE UNIT ON�

• Do not handle the transmitter while you are connected

directly to ground yourself�

• Wear appropriate heavy soled footwear as you would

when working with any high-voltage equipment�

• Prevent object and liquid entry� Never spill liquid of any

kind on the product� Liquid increases the risk of electrical

shock and damage to the product�

• Do not immerse the antennas or case in water� Store in a

dry place� Such measures reduce the risk of electric shock

and equipment damage�

• Do not use where a danger of high voltage contact is

present�

• The user is cautioned not to deliberately connect to

live power lines� If the transmitter indicates the presence

of high voltage, use high voltage precautions to carefully

disconnect the line transmitter from the high voltage source�

• As electromagnetic field lines can be distorted and in-

terfered with it is important to verify the location of un-

derground objects before digging�

• Exposing the utility is the only way to verify its exis-

tence, location, and depth� Several utilities may be under-

ground in the same area� Be sure to follow local guidelines

and one-call service procedures�

• Battery power is the sole power option available on the

ST-305 line transmitter� The transmitter is designed to pro-

tect the user from voltages up to 250 VAC that may be acci-

dentally encountered� The High Voltage LED will light if the

unit encounters more than approximately 62 VAC (RMS)�

• The unit must be disconnected from any external con-

ductors before attempting to access the battery case

or change the batteries� The ST-305 line transmitter is

protected by an interlock which isolates the unit when the

battery case is opened, but standard safety awareness dic-

tates disconnecting the leads rather than relying solely on

this feature�

The information supplied with this product cannot

cover all possible conditions and situations that may

occur, and should be used in conjunction with appro-

priate training, sound judgment, and good work prac-

tices� These factors cannot be built into the product, but

must be supplied by the operator�

The EC Declaration of Conformity (890-011-320�10) will

accompany this manual as a separate booklet when

required�

English – 5

SeekTech ST-305

Description, Specications and

Standard Equipment

The SeekTech ST-305 line transmitter is part of Ridgid’s

SeekTech cable and pipe locating system� The ST-305 is

used to energize a pipe or line with an “active” electrical

signal, so that the underground line may be traced with a

compatible receiver (such as the SeekTech SR-20)� This

allows the line’s location to be correctly marked so it can be

exposed for repair or avoided during excavation�

The ST-305 line transmitter can apply an active tracing

signal to a target conductor in three ways:

• Direct Connect� The transmitter’s leads are connected di-

rectly to the target conductor and a suitable ground� The

ST-305 line transmitter is capable of dual-frequency trans-

mission (sending two frequencies onto a line simultaneous-

ly) in direct-connect mode�

• Inductive Clamp (optional accessory)� The jaws of the

inductive clamp encircle the target conductor; there is no

metal-to-metal contact�

• Inductive Mode (internal coils)� The transmitter is placed

over, and in-line with, a conductor� Its internal antenna gen-

erates a dipole field which energizes the target conductor

below ground, inducing a current into the target conductor�

FCC Limits

47 CFR 15�213 requires that from 9 kHz up to (but not includ-

ing) 45 kHz, peak output power shall not exceed 10 W� From 45

kHz to 490 kHz, it must not exceed 1 W� When the ST-305 is

set to 262 kHz (European version: 93 kHz), the power output

levels are limited:

Low: 0�3 watt

Medium: 0�6 watt

High: 1�0 watt

These values assume a nominal load of 320 ohms�

In compliance with Federal Standard EN-50249, the ST-305

line transmitter is designed to withstand up to 250 VAC 50/60

Hz excitation between the two leads�

Table 1

ST-305 Specifications

Weight:

without batteries 1�6 lb [0�772 kg]

with batteries 2�5 lb [1�1 kg]

Dimensions:

Depth 4�7 in [11�9 cm]

Width 7�75 in [19�6 cm]

Height 3 in [7�6 cm]

Power Source 6 C-Cell Batteries

Alkaline or rechargeable

Power Settings 25 mA to 5 W

Output Power Nominal 5 watts

Default Settings 62 V Maximum (RMS)� 1 kHz, 8 kHz,

33 kHz, 262 kHz selectable frequen-

cies (93 kHz maximum in Europe)�

Standard Equipment

• ST-305

• Direct connect leads and clips

• Operator’s Manual

• 6 C-cell batteries (Alkaline)

Components

Battery

Case

Carry strap

Keypad and

LED Indicators

Connection Leads

and Clips

Figure 1 – ST-305 Components

Grounding Stake Storage

Inductive

Clamp Jack

Figure 2 – ST-305 Components

without batteries: 1.6 lb [0.772 kg]

with batteries: 2.5 lb [1.1 kg]

Depth: 4.7 in [11.9 cm]

Width: 7.75 in [19.6 cm]

Height: 3 in [7.6 cm]

6 – English

SeekTech ST-305

Induction

Mode

Indicator

Induction Mode Toggle

High

Voltage

Warning

Frequency

Indicator

Power/Battery

Indicator

Frequency and

Mode Selection

Power ON/OFF

and Select Key

Figure 3 – Keypad and LED Indicators

• Frequency Indicator� Indicates frequency in use; indicates

when dual-frequency mode is activated�

• Power Indicator� Indicates the relative level of output

power; displays estimated battery power level on start-up�

• Frequency/Mode Selection� Selects desired frequency;

used to initiate dual-frequency mode�

• Power ON/OFF� Used to power the ST-305 on and off and

to set current level�

• Induction Mode Toggle� Used to switch the ST-305 into

Inductive Mode�

• Induction Mode Indicator� Flashes when unit is connected

to an Inductive Clamp� Illuminated in Inductive Mode�

• High Voltage Warning� Warning light when high voltage is

encountered (> ~62V AC RMS)�

Installing/Changing Batteries

To install batteries into the ST-305 line transmitter rotate

the knob on the battery holder counter-clockwise until the

battery cover unscrews� Pull straight back on the knob to

remove the cover� Insert the 6 C batteries as shown on the

inside decals�

Figure 4 – Removing the Battery Cover

Fit the cover into the case and screw down the knob while

firmly pushing in to close� Ensure the cover is firmly screwed

into place�

NOTE: When replacing batteries, use 6 C cells that are the

same type� Do not mix Alkaline with NiCd (NiCad or Nickel

Cadmium) for example� Be sure to replace with batteries

where all of the cells have the same amount of charge� Do

not mix half used alkalines with brand new ones�

Operation Time

Typical operation time varies for the ST-305, depending on

factors such as load, environment, and current transmitted�

Operation at low temperatures will also reduce battery life�

Batteries often recover after being subjected to high loads� If

time is allowed, batteries may recover enough to offer addi-

tional hours of operation�

Battery Check

At start-up, the ST-305 will check available power and will

indicate estimated battery levels by lighting one, two, or

three LEDs in the right hand column (power level) on the

control panel� One LED indicates low batteries, two indicate

medium charge, and three LEDs indicate full battery charge

is available� These levels are only estimates based on a

rapid internal check� A rapid series of beeps will sound if the

battery levels run low in operation�

Sounds of the ST-305

Sounds are associated with specific events or states; they

include:

• Beeps – Beeps when current is flowing; rate increases

with current increase�

• Beeps – Turn ON (4 beeps)/OFF (3 beeps)�

• Short Double Tone – Inductive Clamp connected�

• Long-Short-Short Tone – Inductive Mode�

• Rapid series of beeps – Low Battery Warning�

The sound may be toggled on or off by pressing the Frequen-

cy and Power buttons simultaneously�

Powering ON / OFF

Turn the unit ON by pressing the Power Key� The current

frequency and power-level LEDs will light up�

Turn the unit OFF by pressing and holding the Power Key

for 2 seconds� Three tones will sound�

Automatic Shut Down

To save energy, the ST-305 will automatically shutdown after

an interval which varies with the power setting:

Low Power 4 hours

Medium Power 2 hours

High Power 1 hour

English – 7

SeekTech ST-305

Machine Inspection

WARNING

Before each use, inspect your ST-305 and correct any

problems to reduce the risk of serious injury from elec-

tric shock and other causes and prevent clamp damage.

1� Clean any oil, grease or dirt from all equipment handles

and controls� This helps prevent the machine or control

from slipping from your grip and aids inspection�

2� Inspect the ST-305 for any broken, worn, missing,

misaligned or binding parts or any other condition which

may prevent safe and normal operation� Make sure that

handles move smoothly between positions� If any prob-

lems are found, do not use ST-305 until repaired�

3� Inspect any other equipment being used per its instruc-

tions to make sure it is in good usable condition�

Set-Up

WARNING

Always wear eye protection to protect your eyes against

dirt and other foreign objects.

Set up and operate the ST-305 and work area according

to these procedures to reduce the risk of injury from elec-

tric shock, and other causes, and prevent ST-305 damage.

1� Check work area for:

• Adequate lighting�

• Flammable liquids, vapors or dust that may ignite�

If present, do not work in area until sources have

been identified and corrected� The ST-305 is not

explosion proof and can cause sparks�

• Clear, level, stable dry place for equipment and

operator� Do not use the equipment while standing

in water�

2� Inspect the line to have a signal applied to it�

• The transmitter should only be used on insulted

conductors� When using the transmitter, the target

conductor should be grounded at each end� Other-

wise, the signal may not be strong enough to locate�

• The transmitter is not designed to provide high volt-

age isolation and protection� Do not use where a

danger of high voltage contact is present�

3� Make sure equipment has been properly inspected�

4� Be sure the conductor to be traced is grounded at both

ends�

Select a Frequency on the Transmitter

The ST-305 line transmitter offers four choices of frequency�

Frequency is chosen by pressing on the Frequency Select

Key which will light the LEDs in sequence�

Available frequencies are:

• 1 kHz

• 8 kHz

• 33 kHz

• 262 kHz

• European version: 93 kHz (93,623 Hz�)

The selected frequency is shown by a lit LED� The 262 kHz

is shown by a rapid flashing of the 33 kHz LED (European

version: 93 kHz)�

To set the unit on 262 kHz, press the Frequency Key for

more than one second (long press)� The 33 kHz LED will

start flashing rapidly, indicating a 262 kHz frequency� For

the European version: a long press will select 93 kHz, caus-

ing the 33 kHz LED to flash rapidly)�

Check the Circuit and Adjust Power

Level

Confirm the circuit is grounded by checking the connec-

tion to the ground stake is secure and the stake is firmly

embedded in the ground� To adjust the power level, press

the power button briefly� The ST-305 will cycle through the

low, medium and high power levels�

NOTE: Higher power settings produce more current, which

gives a stronger signal� Less current prolongs battery life�

Signal strength measured by the receiver is directly propor-

tional to the amount of current on the line� More current will

produce a stronger signal received by the receiver�

Use only as much current as is needed to get a strong read-

ing on the receiver�

Generally the lower the resistance the more efficiently

current can be added� A lower resistance indicates an effi-

cient circuit and requires less voltage to charge the line�

Things that increase resistance include paint or dirt on the

connection points, very dry soil, poor ground connection,

poor insulation on a wire, or breaks in the conductor�

The transmitter’s maximum current output depends on the

amount of resistance in the circuit�

CAUTION

If the transmitter is showing low or no current (low or no

beep rate), the signal may be too low to be detected by the

receiver locator and inadequate for tracing.

8 – English

SeekTech ST-305

Check the Receiver

Confirm that the transmitter and receiver are set to the same

frequency� Hold the receiver near the transmitter cables and

confirm a signal is being received�

Operation

WARNING

Useful Operating Tips

• The lower the resistance, the more current will be put on

the line� A good circuit is one that allows enough current

to flow so that the locator gets a solid, clear signal�

• To help lower the resistance of the circuit, scrape away

dirt, paint, and corrosion before connecting to the target

conductor or to the grounding spike�

• A good ground has lower resistance, which allows more

current and a stronger signal� For a better connection

to ground, insert the grounding spike as far as possible�

Moist ground is a better conductor than dry soil, so try

wetting the area if necessary�

• The transmitter’s leads can act as antennas, broadcast-

ing a strong signal� If locating close to the transmitter,

keep the leads short by stowing the excess length on

the transmitter’s body� This will reduce the amount of

interfering signals from the leads�

• Where possible, place the transmitter away from the

area of the intended locate� This is especially true in

Inductive Mode, to avoid coupling through the air with

the receiver�

• Start by using the lowest frequency and the least

amount of current needed to effectively illuminate the

line� Lower frequencies travel farther because they do

not dissipate as quickly� Higher frequencies generally

make it easier to illuminate a line, but they don’t travel

as far and are much more likely to couple onto other util-

ity lines, distorting the signal and reducing the accuracy�

Direct-Connect Method

1� Attach the ST-305 line transmitter to ground and to the

target line�

2� Remove the ground stake from the end of the unit and

insert it into the ground� Connect one of the cable leads

to the grounding spike� The leads are universal, so

either may be used for the ground connect the other

lead to the target conductor�

3� Power the ST-305 ON by pressing the Power Key� A

multiple-tone will sound on powering up� After a short

silence, the unit will begin beeping regularly indicating

current is flowing�

Figure 5 – Connecting the ST-305 Ground Stake

Figure 6 – Connecting the ST-305 using the clip

Figure 7 – Connecting the ST-305 using the

magnet

English – 9

SeekTech ST-305

Figure 8 – Alternative hookup method

WARNING

NEVER CONNECT TO LINES KNOWN TO BE ENER-

GIZED WITH A POTENTIALLY DANGEROUS ELECTRI-

CAL CURRENT� To increase safety, the ground lead

should be attached first� If there were an unknown high

voltage running through the target line, this would

allow a means of redirecting the current away from the

transmitter and operator�

NOTE: Installations which use plastic pipes will typically

have a trace wire installed along the pipe for tracing purpos-

es� Simply clip the transmitter lead to the trace wire�

Dual-Frequency Transmission

The ST-305 line transmitter can be placed in Dual-Frequen-

cy mode by pressing the Frequency Key for over 1 second

(long press)� To exit Dual-Frequency mode, simply repeat

the long press on the Frequency Key�

When in Dual Frequency mode the Frequency Key will cycle

with short presses through the following frequency settings:

1� 262 kHz only (rapid flashing 33 kHz LED) (European

version: 93 kHz)�

2� 33 kHz and 1 kHz dual-frequency transmission (LEDs

for 33 kHz and 1 kHz both lit)�

3� 33 kHz and 8 kHz dual-frequency transmission (LEDs

for 33 kHz and 8 kHz both lit)�

Dual-Frequency transmission is available only in direct

connect mode�

Figure 9 – Frequency Key Options

Inductive Clamp Method

Figure 10 – ST-305 used with an Inductive Clamp

When using an inductive clamp, plug the inductive clamp

jack into the receptacle provided at the end of the transmit-

ter� The Inductive Mode LED will flash rapidly when a clamp

is connected� Clips and leads are not used� Note that for a

clear signal using an inductive clamp, both ends of the utility

should be grounded�

Clamp the inductive clamp around an accessible portion of

the line chosen to trace� The clamp will induce a signal into

the conductor when the transmitter is powered on�

Select frequency and power as with the Direct Connect

Method� Operational frequency choices for use with an

Inductive Clamp are 1 kHz, 8 kHz, and 33 kHz�

10 – English

SeekTech ST-305

Figure 11 – Inductive Clamp in use

To use the ST-305 in Inductive Mode do the

following:

1� Be sure that the transmitter is positioned correctly over

the line�

Figure 12 – Orientation to the Line - Inductive

Mode

NOTE: A slight tilt to the axis of

the conductor can help reduce

the probability of air-coupling

2� Power the transmitter ON� Push the Inductive Mode

switch to induce a signal onto the line without a direct

connection� A long beep will sound when entering

Inductive Mode and the Inductive Mode LED will light �

3� Clips and leads are not used� Note that for a clear

signal using induction, both ends of the utility should

be grounded�

4� The transmitter will emit a series of regular beeps as

long as it is in Inductive Mode�

5� Lower frequencies couple poorly� Therefore, the ST-305

transmitter in Inductive Mode defaults to 33 kHz� Higher

power is usually required for a clear signal in Induc-

tive Mode� Pressing the power key will cycle through

the three available power levels: low, medium, and high�

NOTE: If using the ST-305 in Inductive Mode, be certain to

switch Inductive Mode off if you are going to use the unit in

direct connect mode� Air coupling can create very confus-

ing signals if you inadvertently have the unit set to Inductive

Mode and are trying to use it in direct connect mode�

Coupling through Air

When a line transmitter is set to Inductive Mode, it energizes

a wire or pipe under it by emitting a wave of energy rising

and falling at the selected frequency� This forms an electro-

magnetic field which induces a current into the conductor

(the pipe or wire) underneath it� The field builds and collaps-

es at the frequency generated by the transmitter�

A secondary field is set up around the pipe or wire by the

current induced into it� This secondary field is normally

round in shape, just as it would be if the transmitter were

connected directly� But the primary field from the transmitter,

which does the inducing, is not round, and is not the same

as the field set up on the pipe or wire�

Figure 13 – Air Coupling

The field generated by the transmitter has a shape some-

thing like a football� When the transmitter is sitting on the

English – 11

SeekTech ST-305

ground, roughly half of that field extends below it� The

ends of the “football” extend out past the central axis of the

transmitter�

If the receiver is within this field, it will read clearly and well

on it, rather than on the field around the pipe or wire being

traced� The transmitter and the receiver will couple through

the air for a limited distance around the transmitter� This

problem does not occur with direct connection, and is not

important when using an inductive clamp� But it can be an

issue when using the transmitter in purely Inductive Mode

(i�e�, without a clamp)�

It is important to set up the transmitter, when using the

Inductive Mode, a good 20 or 30 feet [8 to 10 m] away from

the region where tracing occurs, and to be aware of the

difference between the transmitter’s field and the induced

field being traced� They will both have the same frequency,

but the transmitter’s field is limited to the region around the

transmitter itself�

High Voltage Indicator

Whenever the line transmitter encounters a live voltage on

the line higher than 62 VAC, it will flash a red LED at the top

of the keypad� Should this occur, carefully disconnect the

transmitter using high-voltage precautions�

NOTE: The inductor core of the ST-305 emits the signal

when the unit is transmitting in inductive mode� A hard hit or

a drop could possibly damage the core� To test that the core

is intact using a SeekTech SR-20 receiver:

• Power transmitter on

• Set frequency output to 33 kHz

• Set power level to high power

• Power receiver on

• Set to receive 33 kHz

• Move receiver 12 inches from transmitter

If the inductor core is undamaged, the receiver should show

a Signal Strength reading larger than 2000�

Useful Information

Resistance and Impedance

A circuit has a certain amount of resistance to current; this

is measured in ohms (Ω)� Higher resistance reduces the

amount of current that can travel along an underground

line� Factors that affect resistance in the transmitter circuit

are conductivity of the line itself, breaks or faults in the line,

insulation problems with the line, and how well the transmit-

ter is grounded� (Poor grounding makes the return path of

the circuit more resistive)�

Grounding can be affected by soil conditions, length of

grounding rod, or how the line transmitter is connected to

the grounding rod� Good grounding improves the signal

by reducing the total resistance the transmitted current

encounters�

Impedance is a form of resistance which is caused by a

back-force in the electrical field caused by alternating

current (AC)� Impedance can be thought of as “AC resis-

tance” and adds to the resistance in the circuit in propor-

tion to the frequency being used (i�e�, higher AC frequencies

add more impedance than lower ones)�

Using High and Low Frequencies

Understanding the behavior of different frequencies under

different conditions can be important in doing effective and

accurate locates�

In both direct-connect and Inductive Mode, the ST-305

is essentially doing the same thing – imposing a wave of

traceable energy onto the target pipe or line� This electrical

energy rises and falls a certain number of times per second,

which in turn causes a magnetic field to build and collapse

around the conductor at a regular rate� This rate is known

as the frequency of the generated current and of its conse-

quent magnetic field�

Frequency is expressed in terms of hertz (Hz), which means

cycles per second, or kilohertz (kHz), thousands of cycles

per second�

Low Frequencies

The ST-305 will generate frequencies as low as 1 kilohertz�

Low frequencies are especially useful for several reasons�

First, they will travel farther at a detectable level along a

continuous pipe or wire conductor than a high frequency

will� Secondly, lower frequency fields lose less energy to the

area around the conductor� If you can get a clear signal on

your receiver using a low frequency it is generally preferable

because you will be able to trace it further and it will tend

to confine itself to the original conductor more than a high-

frequency signal will� But a low-frequency signal is more

likely to be interrupted by gaps in the line, poor insulation or

hidden by other magnetic fields in the area� It is a “weaker”

signal in that respect� While it doesn’t jump as readily onto

other lines, it will dissipate if traveling on a line with poor

insulation, bare-concentric cable, or bare pipe exposed to

earth, and will follow the path of least resistance, which is

not always the path intended by the operator� This can make

tracing the original conductor difficult�

High Frequencies

The ST-305 will generate frequencies as high as 262 kilo-

hertz (93 kHz in European version)� There are certain

conditions where only higher frequencies will serve� High-

frequency signals are especially valuable when you are

tracing a line that has some sort of interruption—such as

a gasket, or decayed insulation – in the continuity of the

conductor� The reason is that a high-frequency signal can

“jump” some barriers and continue without dissipating as

much signal as a lower frequency would�

A high-frequency signal can also be valuable in getting a

signal on a receiver when there is a poorly grounded circuit,

compared to the signal the same receiver will detect at a

lower frequency� While all currents tend to follow the path

12 – English

SeekTech ST-305

of least resistance, a high-frequency current will buck

this tendency to some degree, reaching across incidental

barriers�

The disadvantage to higher frequencies is that they also

jump onto other conductors� If you have two wires side

by side in a trench, a higher frequency used to trace one

of them may illuminate both of them� Additionally, nearby

metallic objects, or even highly metalized soil, may pick up

a higher frequency and distort the picture seen by the loca-

tor� If a gas line is being “illuminated” with a high frequency

current, it may bleed over onto a water line or a power cable

running nearby, confusing the picture of where the original

line is�

As a general rule, detecting with lower frequencies is more

reliable for the reasons given above, IF you can get a good

signal�

Cleaning

WARNING

Make sure ST-305 is unplugged from transmitter before

cleaning.

The plastic housing may be cleaned with mild cleaner

applied to a cloth� Never submerse the clamp in liquid�

Clean the metal core where the jaws clamp together so no

debris or dirt gets between the jaws�

Storage

Store the ST-305 in a dry, secured, locked area that is out of

reach of children and people unfamiliar with the SeekTech

ST-305�

To avoid tangled cords, wrap the cords back around the

ends of the ST-305 when storing, lead end last, and secure

the ends under the prongs provided on the transmitter� The

ST-305 should be stored in a cool dry place�

If storing the ST-305 for an extended period of time, the

batteries should be removed�

Service and Repair

WARNING

Improper service or repair can make machine unsafe to

operate.

Service and repair of the ST-305 must be performed at a

RIDGID Independent Authorized Service Center�

For information on your nearest RIDGID Independent

Service Center or any service or repair questions:

• Contact your local RIDGID distributor�

• Visit www�RIDGID�com or www�RIDGID�eu to find your

local Ridge Tool contact point�

• Contact the RIDGID Technical Services Department at

rtctechservices@emerson�com or, in the U�S�A� and Can-

ada, call 800-519-3456�

Disposal

Parts of the unit contain valuable materials that can be recy-

cled� There are companies that specialize in recycling that

may be found locally� Dispose of the components in compli-

ance with all applicable regulations� Contact your local

waste management authority for more information�

For EC countries: Do not dispose of electrical

equipment with household waste!

According to the European Guideline 2002/96/

EC for Waste Electrical and Electronic Equip-

ment and its implementation into national legisla-

tion, electrical equipment that is no longer usable must be

collected separately and disposed of in an environmentally-

correct manner�

Battery Disposal

RIDGID is licensed with the Call2Recycle®

program, operated by the Rechargeable

Battery Recycling Corporation (RBRC™)�

As a licensee, RIDGID pays the cost of

recycling RIDGID rechargeable batteries�

In the U�S� and Canada, RIDGID and

other battery suppliers use the Call2Recycle® program

network of over 30,000 collection locations to collect and

recycle rechargeable batteries� Return used batteries to a

collection location for recycling� Call 800-822-8837 or visit

www�call2recycle�org to find a collection location�

For EC countries: Defective or used battery packs/batter-

ies must be recycled according to the guideline 2006/66/EC�

English – 13

SeekTech ST-305

Table 2

Troubleshooting

Problem Remedy

LEDs appear completely dark, or

completely light when unit is ON�

Try Powering the unit OFF and then back ON�

Allow the unit to cool if it has been exposed to excessive heat from sunlight�

Receiver will not pick up the line

transmitter’s signal�

Check that the correct frequency has been selected on both units (See manual for the

specific receiver)� Higher or lower frequencies may be tried�

Check to make sure that the receiver and the line transmitter are in the same mode�

Make sure that the proper functions are activated on the receiver� e�g� activating the line

trace function for line tracing (See manual for the receiver)�

Adjust power upward if possible�

Ensure grounding is adequate�

If using inductive mode, check for core damage using test described in the High Voltage Indi-

cator section�

Unit will not turn ON�

Check orientation of batteries�

Check that the batteries are fresh or charged�

Check to see that the battery contacts are OK�

93 kHz signal not received

Check that receiver is set to the actual 93kHz frequency of 93,622�9 Hz� Some receivers use

a different frequency for 93 kHz (93,696)� Update SeekTech locator software�

14 – English

SeekTech ST-305

English – 15

SeekTech ST-305

NOTES

EMERSON. CONSIDER IT SOLVED.

RIDGID reserves the right to change the specifications of the hardware, software, or both as described in this manual without notice. Visit www.seesnake.com for current

updates and supplemental information pertaining to this product. Due to product development, the photos and other presentations specified in this manual may differ from

the actual product.

Other trademarks or registered trademarks mentioned in this manual are the property of their respective owners.

Printed in U.S.A.

December 2011

748-025-601-0B-P3

English: Rev C

Ridge Tool Company

400 Clark Street

Elyria, Ohio 44035-6001

U.S.A.

www.RIDGID.com

1-800-474-3443

Ridge Tool Europe

Research Park Haasrode

3001 Leuven

Belgium

www.RIDGID.eu

+ 32 (0)16 380 280

RIDGID ST-305 SeekTech Line Transmitter

Product's Documents

User Manual

Specifications

RIDGID ST-305 Questions and Answers