Nortech TD136 User Manual

Nortech International (Pty) Ltd
PO Box 4099 32A Wiganthorpe Road
Willowton Hub Pietermaritzburg
Pietermaritzburg 3201 South Africa
3200 South Africa Reg. No: 98/1095

Tel: [phone] Int. Tel: [phone]
Fax: [phone] Int. Fax: [phone]
Email: [e-mail] URL: www.nortech.co.za

APPROVALS

Originator: Unknown updated: K. Mbatha
Checked: ______________________________ Date: __________________

Engineering Manager: _____________________________
Approved: ______________________________ Date: __________________

Marketing: ____________________________
Checked and approved: ______________________________ Date: __________________

Date: dd/mm/yy Rev CRN No.

19/09/2009 00 2378
19/09/2009 01 2378

Nortech International (Pty) Ltd
All rights reserved
Copyright © 2009
Document Number: 301UM0031_01
Date of Issue: September 2009

This document is for information only and unless otherwise indicated, is not to form part of any contract. In accordance

with the manufacturer’s policy of continually updating and improving design, specifications contained herein are subject

TD136 Enhanced

Vehicle Detector

User Manual

Nortech International (Pty) Ltd
PO Box 4099 32A Wiganthorpe Road
Willowton Hub Pietermaritzburg
Pietermaritzburg 3201 South Africa
3200 South Africa Reg. No: 98/1095

Tel: [phone] Int. Tel: [phone]
Fax: [phone] Int. Fax: [phone]
Email: [e-mail] URL: www.nortech.co.za

Nortech International (Pty) Ltd
All rights reserved
Copyright © 2009
Document Number: 301UM0031_01
Date of Issue: September 2009

This document is for information only and unless otherwise indicated, is not to form part of any contract. In accordance

with the manufacturer’s policy of continually updating and improving design, specifications contained herein are subject

TD136 Enhanced

Vehicle Detector

User Manual

to alteration without notice.

Table of Contents

1. INTRODUCTION .................................................................................................................................... 5

2. TECHNICAL DATA ................................................................................................................................ 6

2.1 Functional Data ................................................................................................................................... 6

2.2 Electrical Data ..................................................................................................................................... 7

2.3 Environmental Data ............................................................................................................................ 7

2.4 Mechanical Data ................................................................................................................................. 8

2.5 Approvals ............................................................................................................................................ 8

3. OPERATING INSTRUCTIONS .............................................................................................................. 9

3.1 Hardware Set-up ................................................................................................................................. 9

3.2 Switch Setting Selections .................................................................................................................... 9

3.2.1 Frequency Switch ........................................................................................................................ 9

3.2.2 Sensitivity ................................................................................................................................... 10

3.2.3 Presence Time ........................................................................................................................... 10

3.2.4 Delay Time ................................................................................................................................. 11

3.2.5 Reset Switch .............................................................................................................................. 11

3.3 Front Panel Indicator ......................................................................................................................... 11

4. PRINCIPAL OF OPERATION .............................................................................................................. 12

4.1 Detector Tuning ................................................................................................................................ 12

4.2 Detector Sensitivity ........................................................................................................................... 13

4.3 Modes of Operation .......................................................................................................................... 13

4.4 Response Times ............................................................................................................................... 13

5. INSTALLATION GUIDE ....................................................................................................................... 14

5.1 Product Safety Requirements ........................................................................................................... 14

5.2 Operational Constraints .................................................................................................................... 14

5.2.1 Environmental Factors to Consider ............................................................................................ 14

5.2.2 Crosstalk .................................................................................................................................... 15

5.2.3 Reinforcing ................................................................................................................................. 15

5.3 Loop and Feeder Specification.......................................................................................................... 15

5.4 Sensing Loop Geometry ................................................................................................................... 16

5.5 Loop Installation ................................................................................................................................ 16

6 CONFIGURATION ................................................................................................................................... 18

6.1 TD136 Enhanced – 120 VAC Vehicle Detector - Order number 305FT0004 ...................................... 18

6.2 TD136 Enhanced – 230 VAC Vehicle Detector - Order number 305FT0001 ...................................... 19

6.3 TD136 Enhanced – 12 to 24 V

7. APPLICATIONS ................................................................................................................................... 20

Vehicle Detector - Order number 305FT0010 ........................... 19

AC/DC

8. CUSTOMER FAULT ANALYSIS ......................................................................................................... 21

8.1 Fault Finding ..................................................................................................................................... 21

8.2 DU100 – DETECTOR DIAGNOSTIC UNIT ....................................................................................... 22

8.2.1 Interpretation of DU100 readings ............................................................................................... 22

8.2.1.1 Frequency ........................................................................................................................................................ 22

8.2.1.2 Frequency drift ............................................................................................................................................... 23

8.2.1.3 Sensitivity ....................................................................................................................................................... 23

8.2.1.4 Time ............................................................................................................................................................... 23

8.2.1.5 Crosstalk ........................................................................................................................................................ 24

8.3 Functional Test ................................................................................................................................. 24

APPENDIX A - FCC ADVISORY STATEMENT.............................................................................................. 25

APPENDIX B – INSTALLATION OUTDOORS ............................................................................................... 26

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 2 of 29

Appendix B.1 IEC 60950-22:2005 – Outdoor cabinet ............................................................................... 26

Appendix B.2 IEC 60950-22:2005 - Northern Europe ............................................................................... 26

Appendix B.3 IEC 60950-1:2005 – Overvoltage Category ........................................................................ 26

APPENDIX C –REQUEST FOR TECHNICAL SUPPORT FORM ................................................................... 27

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 3 of 29

WARNING: 1. This unit must be earthed!
WARNING: 2. Disconnect power before working on this unit!
WARNING: 3. Installation and operation by service personnel only!
WARNING: 4. No user serviceable parts inside. Only service personnel

may open the unit to change internal settings. Warranty
void if cover removed !

WARNING: 5. Always suspend traffic through the barrier area during

installation and testing that may result in unexpected
operation of the barrier.

WARNING: 6. USA

FCC Advisory Statement – Refer to Appendix A at the
end of this document.

WARNING: 7. Europe

Disposing of the product:

This electronic product is subject to
the EU Directive 2002/96/EC for
Waste Electrical and Electronic
Equipment (WEEE). As such, this
product must not be disposed of at
a local municipal waste collection
point. Please refer to local
regulations for directions on how to
dispose of this product in an
environmental friendly manner.

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 4 of 29

1. INTRODUCTION

The TD136 Enhanced Vehicle Detector is a single channel microprocessor based detector designed
specifically for traffic control applications. The TD136 Enhanced Vehicle Detector has been designed using the
most up-to-date technology in order to meet the requirements of a vast number of traffic applications in terms
of operating conditions and functional options available to the user.

The primary function of the detector is to detect vehicle presence by means of an inductance change caused
by the vehicle passing over a wire loop buried under the road surface. The detector has been designed for
ease of installation and convenience.

The detector has been designed for ease of installation and convenience. The various modes are selected by
changing the positions of the switch on the front of the unit.

The switches allow for different loop frequency settings, sensitivity settings and mode settings.
The TD136 Enhanced Vehicle Detector provides visual output (LED) on the front of the enclosure and relay

change-over contacts are taken on the 11 pin connector at the rear of the enclosure. The LED indicates the
power has been applied to the unit, that a vehicle is present over the loop and if there is a fault on the loop.

The Presence relay is fail-safe and will close on a vehicle detect or in the event of power failure. The TD136
Enhanced Vehicle Detector is also provided with an integral fault relay, which will provide an output in the
event of a loop fault condition.

Related Documents:

TD136 Enhanced Vehicle Detector Data Sheet Document No. 305DS0002
Installation Leaflet Document No. 300LF0006
Diagnostic Unit DU100 User Manual Document No. 895UM0001

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 5 of 29

2. TECHNICAL DATA

2.1 Functional Data

Tuning Fully Automatic

Self-tuning range 20 to 1500 µH
Sensitivity Four step switch selectable

High 0.02 %∆L/L
Medium High 0.05 %∆L/L
Medium Low 0.10 %∆L/L
Low 0.50 %∆L/L

Frequency Four step switch selectable
Frequency dependent on loop size

Relay Outputs Presence Relay

Presence Relay Fail-safe

Presence Time Switch selectable:

1 Second
4 Minutes
40 Minutes
No fixed time-out (dependant on inductance change) Approx.
1 hour for 3 %∆L/L

Delay Time Switch selectable:
0 Seconds
10 Seconds
20 Seconds
30 Seconds

Fault Output Separate fault monitor output relay
Operates under the following conditions:

Response Times Turn – on 60 milliseconds
Turn – off 60 milliseconds

Drift Compensation Rate Approx. 1 %∆L/L per minute
Visual Indications 1 X Power LED - Red

1 x Channel Status LED - Green
Reset Reset by push button on front of enclosure
Surge protection Loop isolation transformer, gas discharge tubes, and Zener

Fault Relay

1. Loop open/short circuit

2. Detector/power fault

Diode clamping on loop input

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2.2 Electrical Data

Power requirements 12 V -10% to 24 V +10% DC/AC 48 to 62 Hz

120 VAC ±10% (48 to 62 Hz)

230 VAC ±10 % (48 to 62 Hz)

Requirement: 1.5 VA Maximum @ 230 V

Relay Contact Rating Relays rated – 5 A @ 230 V

Maximum current as per graph below

2.3 Environmental Data

Optional – Opto Isolated 50mA @ 30V

AC

DC

For ambient temperatures above 60°C De-rate the rel ay

Storage Temperature -40°C to +80°C
Operating Temperature -40°C to +70°C
Humidity Up to 95% relative humidity without condensation
Circuit protection Conformal coating over the PCB and all components
IP Rating IP30

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2.4 Mechanical Data

Housing Material ABS blend

Mounting Position Shelf or DIN rail mounting

Connections 11-pin Submagnal (JEDEC No. B11-88)

Size of Housing 78mm (H) X 41mm (W) X 78mm (D)

80 mm

40.6 mm

77.7 mm

2.5 Approvals

CE Regulations: EN 301 489-3 Equipment Type: III Class of Equipment: 2

EN 50293 Performance Criteria B

Safety IEC / EN 60950-1

75.9 mm

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 8 of 29

SW2

SW1

Off Off High

On Off Medium

-

High

Off On Medium

-

Low

On On Low

3. OPERATING INSTRUCTIONS

3.1 Hardware Set-up

The TD136 Enhanced Vehicle Detector is a single channel traffic detector designed to be shelf or DIN
rail mounted with the controls and visual indicators at the front and wiring at the rear of the enclosure.

The power, loop and relay outputs are all connected to the single 11-pin plug, which is mounted at the
rear of the enclosure.

3.2 Switch Setting Selections

3.2.1 Frequency Switch

The frequency switches are the lower two switches, numbered 1 and 2. There are four frequency
selections and are set out as follows:

The frequency switches allows the loop to be shifted higher or lower depending on the switch position.
The frequency of the loop is determined by the loop size, and the frequency of the switch simply
causes a frequency shift on the loop.

Where more than one detector is used the detectors must be set-up to ensure that there is no cross­talk (interference) between the detectors. This can be achieved by ensuring that the loops of the two
detectors are spaced sufficiently apart (approximately 2 metres between adjacent edges) and also
ensuring that the detectors are set to different frequencies.
As a general rule, the detector connected to the inductive loop with the greatest inductance should be
set to operate at the lowest frequency. Loop inductance increases as loop size, number of turns in the
loop and feeder length increases.

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 9 of 29

SW4

SW3

Off Off High

On Off Medium

-

High

Off On Medium

-

Low

On On Low

SW6

SW5

Off Off

∞ no fixed time

On Off 40 min

Off On 4 min

On On 1 sec

3.2.2 Sensitivity

The sensitivity of the detector allows the detector to be selective as to the change of inductance
necessary to produce a detect. There are four sensitivity selections and are set as follows: -

3.2.3 Presence Time

The presence time is a mode, which allows the detector to have a presence time of no longer than the
time set. The mode is selected by switches No.5 and 6 on the front of the enclosure and is as follows: -

The presence time as shown above may be altered according to the requirements.
The 1 second setting will give a pulse on detection of a vehicle with a duration of 1 second. The

detector will immediately re-adjust to the normal operating point and will give another detect in the
event of a further change in the loop inductance, i.e. the detector may be used as a passage detector
in this mode.

The 4 minute and 40 minute settings work in the same way as the 1 second setting; however the
detector will now give outputs of 4 minutes or 40 minutes. If the vehicle which caused the inductance
change moves off the loop then the detector will go out of detect and this time will be reset to zero for
the next detect cycle. The detector may undetect before the expired time period if the change in
inductance for the vehicle is small.

The “no fixed time-out” setting does not have a fixed time period and the presence time is dependant
on the magnitude of the inductance change caused by the vehicle over the loop.

On times longer than 1 second there will be a “paralysis time” of approximately 2 seconds between
actuations.

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SW8

SW7

Off Off Off

On Off 10 secs

Off On 20 secs

On On 30 secs

3.2.4 Delay Time

Delay time is a mode in which the output of the detector is delayed by the time specified. If the vehicle

leaves the loop before the time has expired, no output will result. The mode is selected by switches

No.7 and 8 on the front of the enclosure and is as follows:

3.2.5 Reset Switch

The detector automatically tunes to the inductive loops connected to it when power is applied, whether

on initial installation or after any break in the power supply. Should it be necessary to retune the

detector, as may be required after the changing of any switch selections or after moving the detector

from one installation to another, momentary operation of the RESET switch will initiate to the

automatic tuning cycle.

3.3 Front Panel Indicator

While the detector is tuning, the ON (Red) LED will glow .The OUTPUT LED (Green) will extinguish
when the system is tuned. The green LED will flash at a rate of 1 Hz during tuning. This is used to
indicate the frequency of the loop to the user. Every flash of the LED is equivalent to 10 kHz. It will
stop when the operating frequency is reached. This operation is also performed whenever the reset
button is depressed.

The ON (Red) LED will glow permanently to indicate that the unit is functional. The red LED also
serves as an optical interface to the DU100 Diagnostic Unit.

If faults exist with the loop the green LED will come on and flash off at the rate of 2Hz indicating the

fault. If the fault is self-healing the detector will continue to operate but the LED will remain on

indicating to the user that a fault has occurred. The LED will go off for a moment during an undetect

indicating this, thereafter returning on. This condition can be restored by removing the power or by

depressing the reset button.

The green LED will also glow whenever a vehicle is detected passing over the inductive loop.

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4. PRINCIPAL OF OPERATION

The inductive loop vehicle detector senses the presence of a vehicle over an area defined by a loop of
two or more turns of wire laid under the road or pavement surface. This loop of wire is connected to
the detector by a twisted pair of wires called a loop feeder.

A vehicle passing over a sensing loop causes a small reduction in the inductance of the loop, which is
sensed by the detector. The sensitivity of the detector is adjustable to accommodate a wide range of
vehicle types as well as different loop and feeder combinations.

Upon detection of a vehicle passing over the loop the detector operates its output relays which may be
used to indicate controls associated with the installation.

4.1 Detector Tuning

Tuning of the detector is fully automatic. When power is applied to the detector upon installation of the
system, or when a reset is initiated, the detector will automatically tune itself to the loop to which it is
connected. The detector will tune to any loop to inductance range 20 to 1500 microhenries.

This wide range ensures that all loop sizes and feeder combinations will be accommodated in the
tuning range of the detector.

Once tuned, any slow environmental change in loop inductance is fed to a compensating circuit within
the detector, which keeps the detector correctly tuned.

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4.2 Detector Sensitivity

Sensitivity of the detection system is dependent on factors such as loop size, number of turns in the
loop, feeder length and the presence of metal reinforcing beneath the loop.

Sensitivity levels of the TD136 Enhanced Vehicle Detector have been carefully optimized for traffic
control applications.

The nature of the application determines the required sensitivity, which may be adjusted by means of
the sensitivity, switches on the front of the enclosure.

4.3 Modes of Operation

In the presence mode the detector will give a continuous output during the presence of a vehicle over
the inductive loop providing that the preset time has not expired. Upon expiry the detector will undetect
and tune out the vehicle over the loop.

The presence output is known as a fail-safe output. This implies that in the event of a power failure the
detector will give a detect output. The fault relay is also failsafe and will generate an output whenever
a loop is faulty or the unit is unable to tune to the loop.

4.4 Response Times

The response time of the detector is the time taken from when a vehicle moves over the loop to when
the detector gives an output.

The response times of the TD136 Enhanced Vehicle Detectors have been adjusted to provide
adequate response to vehicles in traffic control applications.

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5. INSTALLATION GUIDE

Optimum functioning of the detector module is largely dependent on factors associated with the
inductive sensor loop connected to it. These factors include choice of material, loop configuration and
correct installation practice. A successful inductive loop vehicle detection system can be achieved
bearing the following constraints in mind, and strictly following the installation instructions. The detector
must be installed in a convenient weatherproof location as close as possible to the loop.

5.1 Product Safety Requirements

• WARNING: The unit must be EARTHED.

• WARNING: Disconnect the power before working on the unit.

• WARNING: On 120 VAC and 230 VAC models a readily accessible disconnect device

MUST be incorporated into the Mains wiring (As per EN 60950 section 1.7.2)

• WARNING: All models the power supply to the unit MUST have short circuit protection
and over current protection installed at the power supply source (As per EN
60950 section 1.7.11) typically this will be a 5 Amp Magnetic Circuit Breaker
for AC models and a fuse for DC models.

• WARNING: This product must be installed in an enclosure.

• WARNING: No user serviceable parts inside. Warranty void if cover removed.

ONLY SERVICE PERSONNEL MAY OPEN THE UNIT TO CHANGE THE
INTERNAL SETTINGS.

• WARNING: Only use CE approved 11 pin relay bases such as Nortech Part No.
CTR119090 or equivalent.

As an alternative to the 11 pin realy base, Nortech has a 11 pin wiring
harness, Nortech Part No. 301FT0041, which can only be used in SELV
voltage (less than 60 VDC or less than 42 VAC) applications.

5.2 Operational Constraints

5.2.1 Environmental Factors to Consider

Even though the TD136 Enhanced Vehicle parking detectors are housed, the system integrator MUST
ensure that the detector is installed in a housing/fire enclosure to protect it from the environment.

The TD136 Enhanced Vehicle parking detectors are rated to operate over the industrial temperature
range but the rate of temperature change MUST not exceed 1°C per minute. This system integrator
MUST ensure that the housing used complies with this rate of temperature change requirement.

For installation Outdoors refer to Appendix B.
For additional information on Environmental Factors refer to the section “Environmental Influences

to Design Parameters” in the “Loops and Loop Installations” Manual, Nortech Document No. MKT05.

301UM0031_01 TD136 Enhanced Vehicle Detector User Manual Page: 14 of 29

5.2.2 Crosstalk

When two loop configurations are in close proximity, the magnetic fields of one can overlap and disturb
the field of the other. This phenomenon, known as crosstalk, can cause false detects and detector
lock-up.

Crosstalk between adjacent loops operating from different detector modules can be eliminated by:

1. Careful choice of operating frequency. The closer together the two loops, the further apart the
frequencies of operation must be.

2. Separation between adjacent loops. Where possible a minimum spacing of 2 metres between
loops should be adhered to.

3. Careful screening of feeder cables if they are routed together with other electric cables. The
screen must be earthed at the detector end only.

4. Running feeder cables in their own slots, separated by at least 300mm
For additional information on Crosstalk refer to the section “Crosstalk Prevention” in the

DU100 Diagnostic Unit User Manual Nortech Document No. 895UM0001.

5.2.3 Reinforcing

The existence of reinforced steel below the road surface has the effect of reducing the inductance,
and therefore the sensitivity, of the loop detection system. Hence, where reinforcing exists 2 turns
should be added to the normal loop, as referred to in section 5.4.

The spacing between the loop and steel reinforcing should be greater than 150 mm, although this is
not always practically possible. The slot depth should be kept as shallow as possible, taking care that
the feeder remains exposed after the sealing compound has been applied.

5.3 Loop and Feeder Specification

Extensive studies have been undertaken over the years by various agencies around the world in order
to ascertain the optimum loop installation materials.

As an insulated conductor is a prerequisite, PVC covered cable has been used for many years as a
first choice, but tests have shown, in fact, that this is unsuitable for long term installations. The PVC
tends to become porous with the result that adjacent loops become electrically coupled to one
another, with resultant crosstalk implications. Instability and susceptibility to electrical interference can
also result.

The insulation must withstand wear and abrasion from the shifting streets, moisture, and attack by
solvents and oils, as well as withstand the heat of high temperature sealants.

Silicone insulated cable has emerged as one of the preferred insulation materials. Other insulation
materials are rubber, thermoplastic, synthetic polymer and cross linked polyethylene.

Stranded loop wire is preferred over solid wire. Because of its mechanical characteristics, a stranded
wire is more likely to survive bending and stretching than a solid.

A heavy gauge conductor is definitely desirous in order to maintain the loop Q-factor. The loop and
feeder should preferably constitute a single length of insulated multi-stranded copper conductor, with
no joints and with the copper having a minimum cross section 1.5 mm2. The feeder is twisted to
minimize the effect of electrical noise.

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Joints in the loop or feeder are not recommended. Where this is not possible, joints
are to be soldered and terminated in a waterproof junction box. This is extremely important for reliable
detector performance. Other forms of joins such as those available in kits, where the joint is properly
sealed against moisture, are also permitted.

5.4 Sensing Loop Geometry

NOTE: 1) The circumference of the loop must not exceed 30 m.

2) The area of the loop must not exceed 30 m² and must be not less than 1 m².

3) The loop must be constructed as detailed below.

Sensing loops should, unless site conditions prohibit, be rectangular in shape and should normally be
installed with the longest sides at right angle to the direction of traffic movement. These sides should
ideally be 1 metre apart.

The length of the loop will be determined by the width of the roadway to be monitored. The loop should
reach to within 300mm of each edge of the roadway.

In general, loops having a circumference measurement in excess of 10 metres should be installed
using two turns of wire, while loops of less than 10 metres in circumference, should have three turns
or more. Loops having a circumference measurement less than 6 metres should have four turns. It is
good practice at time of installation to construct adjacent loops with alternate three and four turn
windings.

For additional Information on loop geometry refer to the following documents:
“INDUCTIVE LOOP VEHICLE DETECTION” – Nortech Doc. No. MKT01.
“TRAFFIC DETECTION CONCEPTS” – Nortech Doc. No. MKT02.
“TRAFFIC APPLICATION MANUAL” – Nortech Doc. No. MKT04

5.5 Loop Installation

All permanent loop installations should be installed in the roadway by cutting slots with a masonary
cutting disc or similar devise. A 45° crosscut should be made across the loop corners to reduce the
chance of damage that can be caused to the loop at right angle corners.

NOMINAL SLOT WIDTH: 4 mm
NOMINAL SLOT DEPTH : 30 mm TO 50 mm

A slot must also be cut from the loop circumference at one corner of the loop to the roadway edge to
accommodate the feeder.

A continuous loop and feeder is obtained by leaving a tail long enough to reach the detector before
inserting the cable into the loop slot. Once the required number of turns of wire are wound into the slot
around the loop circumference, the wire is routed again via the feeder slot to the roadway edge. A
similar length is allowed to reach the detector and these two free ends are twisted together to ensure
they remain in close proximity to one another. (Minimum 20 turns per metre) Maximum recommended
feeder length is 100 metres. It should be noted that the loop sensitivity decreases as the feeder length
increases, so ideally the feeder cable should be kept as short as possible.

The loops are sealed using a “quick-set” black epoxy compound or hot bitumen mastic to blend with
the roadway surface.

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300mm

45° CROSSCUT TO PROVIDE STRESS

+/- 2 m Depending on Road

MIN DISTANCE APART

MAX DISTANCE APART

SAW CUTS

2 m (Road Width = 2 m)

3 m (Road Width = 4 m)

No Limit

300mm

1

1

CURB/ROAD
EDGE

TRAFFIC

Figure 5.1 Adjacent loops connected to different detector modules

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Figure 5.2 Slot Details

6 CONFIGURATION

WARNING: 8. The connector PIN assignments vary from model

NOTE 1: The tables below show the PIN assignments for Nortech’s standard TD136 Enhanced

models on other models the pin assignments may change.

WARNING: 9. The wiring harness is only rated for SELV

NOTE 2: All relay contact descriptions refer to the tuned and undetected state.

to model
Refer to the label on the side of the unit for

connector PIN assignment.

voltages (less than 60Vdc or less than 42Vac).
If the relays are to switch higher voltages use

CE LVD approved 11 pin sockets

6.1 TD136 Enhanced – 120 VAC Vehicle Detector - Order number
305FT0004

11-pin connector wiring for TD136 Enhanced Vehicle – 120 VAC Detector - Order number
305FT0004

301FT0045
Wiring Harness
Wire COLOUR

Red 1 Live Power supply
Black 2 Neutral
Grey 3 Fault Relay N/O
Violet 4 Fault Relay Common
Yellow 5 Presence Relay N/O
Brown 6 Presence Relay Common
Blue 7 Loop Twist this
Blue 8 Loop
Green/Yellow 9 Earth
Pink 10 Presence Relay N/C
White 11 Fault Relay N/C

11 PIN
Connector
Pin No.

FUNCTION

230V 10% 50/60 Hz

Pair

WARNING: 10. The wiring harness wire colour to PIN No.

assignment only applies to wiring harness Part
No. 301FT0045. Other wiring harnesses will have
different wire colour to PIN No. assignments

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AC/DC

Blue 8 Loop

6.2 TD136 Enhanced – 230 VAC Vehicle Detector - Order

number 305FT0001

11-pin connector wiring for TD136 Enhanced Vehicle – 230 VAC Detector - Order number
305FT0001

301FT0041
Wiring Harness
Wire COLOUR

Red 1 Live Power supply
Black 2 Neutral

Grey 3 Fault Relay N/O
Violet 4 Fault Relay Common
Yellow 5 Presence Relay N/O
Brown 6 Presence Relay Common
Blue 7 Loop Twist this
Blue 8 Loop
Green/Yellow 9 Earth
Pink 10 Presence Relay N/C
White 11 Fault Relay N/C

11 PIN
Connector
Pin No.

WARNING: 11. The wiring harness wire colour to PIN No.

assignment only applies to wiring harness Part
No. 301FT0041. Other wiring harnesses will have
different wire colour to PIN No. assignments

6.3 TD136 Enhanced – 12 to 24 V
305FT0010

FUNCTION

230V 10% 50/60 Hz

Pair

Vehicle Detector - Order number

AC/DC

11-pin connector wiring for TD136 Enhanced Vehicle – 12 to 24 V
number 305FT0010

301FT0041 Wiring
Harness Wire
COLOUR

Red 1 Live Power supply
Black 2 Neutral

Grey 3 Fault Relay N/O
Violet 4 Fault Relay Common
Yellow 5 Presence Relay N/O
Brown 6 Presence Relay Common
Blue 7 Loop Twist this

Green/Yellow 9 Earth
Pink 10 Presence Relay N/C
White 11 Fault Relay N/C

11 PIN
Connector
Pin No.

FUNCTION

12V –10% to 24V +10%

Pair

Detector – Order

AC/DC

WARNING: 12. The wiring harness wire colour to PIN No.

assignment only applies to wiring harness Part
No. 301FT0041. Other wiring harnesses will have
different wire colour to PIN No. assignments

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7. APPLICATIONS

The TD136 Enhanced Vehicle single channel Detector can be used in a variety of applications in the
traffic and vehicle control environments.

For VA (Vehicle Actuated) or SVA (Semi Vehicle Actuated) traffic intersection control
Some of the features that make the TD136 Enhanced Vehicle Detector ideal for these purposes have

been described in the preceding paragraphs.
For more details on traffic applications, refer to “Traffic Applications Manual”, Document No.

MKT0004.

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8. CUSTOMER FAULT ANALYSIS

8.1 Fault Finding

FAULT

Red LED does not glow on
power up.

After the initial tune period the
Green LED flashes (ON for 1
second and OFF for ½
second)

After tuning, the loop output
LED flashes intermittently and
the relay chatters.

CAUSED BY

If the indicator is off then there
is a fault on the power
connection to the unit.

Unit cannot tune to the loop
due to faulty loop or feeder
connection.

Loop may be too small or too
large.

Faulty detector unit.

The loop is getting spurious
detects due to:

a) Crosstalk with adjacent
detector.

b) Faulty loop or feeder
connection.

REMEDY

Check power feed to the unit.

Check loop installation and
connections.

Recut as per installation
instructions.

Replace unit.

a) Change frequency
setting.

b) Check that the feeders are
correctly connected and
adequately twisted.

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8.2 DU100 – DETECTOR DIAGNOSTIC UNIT

The DU100 Diagnostic unit is a hand-held test instrument that has been designed to operate with the
TD136 Enhanced Vehicle Detector to provide installation / service personnel with positive verification
of the correct installation and operation of the vehicle detector.

The following parameters may be verified using this instrument:

1. Detector type and version

2. Loop status Display of loop frequency and magnitude of current change of loop
inductance %∆L/L.

3. Frequency Readout of the actual loop operating frequency and the magnitude of

the frequency drift since the last re-tune.

4. Sensitivity Displays the Minimum and Maximum changes of Inductance %∆L/L that
caused a detect since the last re-tune.

5. Status Displays the current status of the detector i.e. Undetect, Detect, Open
circuit, Short circuit or Indeterminate.

6. Time The time in days and hours since the last re-tune and the reason for
the last re-tune i.e. Reset: manual or power failure, Loop short circuit,
Loop open circuit, Indeterminate or an Inductance change of greater
than 15 % ∆ L/L (typical)

This historical information is invaluable in providing information about
intermittent faults.

7. Crosstalk Allows for the comparison of the operating frequencies of detector
loops in close proximity to each other. If the operating frequencies are
to close the DU100 test will indicate a failure.

For further information refer to the Diagnostic Unit DU100 User Manual Document No. 895UM0001.
It is highly recommended that after installation of a detector (or if the loop has been changed in any

way) that the DU100 Diagnostics Unit is used to verify the correct operation of the detector. A record
of the readings should be kept so that if there is a problem in the future a comparison can be made to
identify what has changed. The form in Appendix A could be used to record these readings.

8.2.1 Interpretation of DU100 readings

8.2.1.1 Frequency

For the TD136 Enhanced Vehicle Detector the Minimum frequency is 12 kHz and the Maximum
frequency is 85 kHz

If a 20 µH loop is connected directly (no feeder cable) to the Detector and the Frequency
switches are set to “High Frequency” the typical frequency would be 84 kHz

If a 1500 µH loop is connected directly (no feeder cable) to the Detector and the Frequency
switches are set to “Low Frequency” the typical frequency would be 13 kHz

If the Frequency reading from the DU100 is close to the Maximum Frequency the inductance of
the LOOP is too small – you need to add turns to the loop

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If the Frequency reading from the DU100 is close to the Minimum Frequency the
inductance of the LOOP is too high and you need to remove turns from the loop

If the detector is operating close to either limit it is possible that either the frequency drift caused
by environmental changes or the shift in frequency caused by a large ∆L/L detect will cause the
frequency to go outside the limits and cause a retune.

8.2.1.2 Frequency drift

The TD136 Enhanced Vehicle Detector can handle environmental conditions that cause the
frequency to drift up to at a rate of approximating 1%∆L/L per minute.

If the Drift reading approaches this value the detector will have problems tracking the
environmental change

If the drift is higher than say 0.5 %∆L/L per minute this will indicate a possible fault with the loop
or feeder cable. Possibly the wire insulation has deteriorated and moisture is causing a short to
earth or that wires of the loop are no longer encapsulated and are moving.

For more information about Frequency drift refer to the “Theory of Application” section in
Diagnostic Unit DU100 User Manual Document No. 895UM0001

8.2.1.3 Sensitivity

8.2.1.4 Time

For a standard loop of 1.0 metres by 2.0 metres with 2 turns (circumference less than 10 m) and
a ten meter feeder cable the following table shows typical sensitivity values for different vehicle
types

VEHICLE TYPE

Metal Supermarket Trolley 0.3 to 2
Bicycle 0.04
Motorbike 0.12
Articulated Truck 0.38
Four Wheel Drive 0.40
5 Ton Tip Truck 0.45
Motor Car > 1.00
Forklift > 1.00

For more information about Sensitivity refer to the “Theory of Application” section in Diagnostic
Unit DU100 User Manual Document No. 895UM0001

This is a powerful tool in identifying problems with an installation. The time since the last retune of
the detector will let you know when the event occurred and the reason will inform you of what
caused the event

%∆∆∆∆L/L

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8.2.1.5 Crosstalk

For information about resolving crosstalk refer to the “Theory of Application” section in Diagnostic
Unit DU100 User Manual Document No. 895UM0001

8.3 Functional Test

To test a detector, connect it to an inductive loop with a total inductance in order of 300 microhenries.
(This may be achieved in the workshop by winding (x) turns of wire on non-metal former of diameter
(y)).

X = 19 turns 0,25 mm wire
Y = 238 mm ( 9.4 inches )

Bring a small metal object approximately the size of a matchbox close to the loop coil.
The following will happen on detection:

The OUTPUT LED will light up
The PRESENCE output relay will operate
The PULSE relay will operate momentarily (approximately 150ms duration)

To check the sensitivity, presence time etc., a calibrated tester should be used, which compromises, of
a calibrated loop similar to the one described above with a moveable vane, which can be moved over
the loop at pre-determined heights.

This device together with the DU100 hand-held test instrument will allow comprehensive analysis of
the operating characteristics of the detector.

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APPENDIX A - FCC ADVISORY STATEMENT

NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference in a residential installation.

Operation is subject to the following two conditions:

1 This device may not cause harmful interference, and
2 This device must accept any interference received, including interference that may cause

undesired operation

This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications.

However, there is no guarantee that interference will not occur in a particular installation. If this equipment
does cause harmful interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one or more of the following
measures:

Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.

The following booklets prepared by the Federal Communications Commission (FCC) may also prove helpful:

• How to Identify and Resolve Radio-TV Interference Problems (Stock No. 004-000-000345-4)

• Interface Handbook (Stock No. 004-000-004505-7)

These booklets may be purchased from the Superintendent of Documents, U.S. Government Printing Office,
Washington, DC 20402.

WARNING: 13. Changes or modifications not expressly approved

by the party responsible for compliance could void
the user’s authority to operate the equipment.

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APPENDIX B – INSTALLATION OUTDOORS

Appendix B.1 IEC 60950-22:2005 – Outdoor cabinet

If the PD136 Enhanced Detector is to be installed outdoors it must be installed in a
cabinet / housing that complies with the requirements of IEC 60950-22:2005 for a
minimum of pollution degree 2.

Appendix B.2 IEC 60950-22:2005 - Northern Europe

To achieve outdoor operation down to -50 °C as required by IEC 60950-22:2005 for
Northern Europe (Finland, Norway and Sweden) a heater with a thermostat must be
included in the cabinet that houses the PD130 Enhanced Detector.

Appendix B.3 IEC 60950-1:2005 – Overvoltage Category

If the unit is likely to be exposed to transient overvoltage greater that IEC 60950-1
Overvoltage Category II additional protection must be provided external to the unit on
the supply lines.

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APPENDIX C – REQUEST FOR TECHNICAL SUPPORT FORM

For Technical support please fill in the form below and send it to your supplier. It is recommended that at
installation you complete this form as a record of the Installation. If there is a problem later on you can identify
what has changed.

For locating faults in “Nortech Inductive Loop Vehicle Detector” installations it is highly recommended that
you use the DU100 DIAGNOSTICS UNIT. Please refer to the DU100 user manual Doc. No. 895UM0001 for
details of how to operate the DU100.

Contact Details:- Your Name: __________________________________________

Your company: ____________________________

Telephone No. _______________________ Mobile/Cellphone No. ________________________
FAX No. ____________________________ E-mail: ______________________________
Postal address: ____________________________________
_____________________________________
_____________________________________

Product Model (i.e. TD136 Enhanced Vehicle Detector) _____________________________________
Product FT No. 305FT_____________ Product Serial Number: _______________________
Site Name: __________________________________ Detector No. (at the site): ________________
What are the settings of the switches on the front of the unit ON or OFF
Switch 1 ___________ (FREQ Frequency)
Switch 2 ___________ (FREQ Frequency)
Switch 3 ___________ (SENS Sensitivity)
Switch 4 ___________ (SENS Sensitivity)
Switch 5 ___________ (PRES Presence Time)
Switch 6 ___________ (PRES Presence Time)
Switch 7 ___________ (DELAY Delay Time)
Switch 8 ___________ (DELAY Delay Time)

What application is this unit used in (short description)_____________________________________
_________________________________________________________________________________
_________________________________________________________________________________

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POWER SUPPLY DETAILS:

Nominal Voltage: _______ V Minimum Voltage: _______ V Maximum Voltage: ________ V
AC or DC ? ______________ If AC then the Frequency _______ Hz

LOOP DETAILS

Size of loop: ___ m by ___ m Shape of loop: _________________________________
Number of Turns: _____
Size of wire used (mm2 or AWG) _____________
Type of wire insulation and thickness of insulation:_____________
How far below the surface is the loop: __________ mm
Are there any metal objects below the loop such as concrete reinforcing, water pipes etc if yes please give

details:
_____________________________________________________________________________

____________________________________________________________________________
_____________________________________________________________________________
Are there any power cables below the loop if yes please give details:

_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________

Are there any other loops in the area if so how many? ________ and how close to this loop are they?
________ m

FEEDER CABLE DETAILS

Length of feeder cable______________m
Size of wire used (cross sectional area of copper mm2 or AWG) _____________ (should be 1.5 mm

larger)
Type of wire insulation and thickness of insulation:_____________ (should be __________ )

Type of feeder cable used (screened, armoured, multicore, etc.)
____________________________________________________________________________________
____________________________________________________________________________________
In the feeder cable how many twists per meter are there?____________ (should be more than 20 per metre)

2

or

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Are there any other cables close to this feeder cable? If so please give details:

_________________________________________________________________________
_______________________________________________________________________

_________________________________________________________________________

FEEDER CABLE AND LOOP DETAILS

DC resistance of Feeder plus Loop: __________ ohms
Inductance of Feeder plus Loop: __________ Micro Henries
Loop and feeder resistance to earth (with detector unplugged) using a 500V Megger: ___________ Ohms

(should be greater than 10 Mega Ohms)

READINGS FROM DU100 DIAGNOSTICS UNIT

Frequency: ______________ kHz Loop Frequency Drift: __________ %
If you do not have a DU100 when the detector tunes how many times does the green LED flash____________

Inductance Change for each type of vehicle that is encountered on this site.

the DU100 and reset the detector between each reading):

Bicycle: __________ %∆L/L
Motorbike: __________ %∆L/L
Car: __________ %∆L/L
Articulated truck: __________ %∆L/L
Four wheel drive: __________ %∆L/L
5 Ton Tip Truck: __________ %∆L/L
Forklift: __________ %∆L/L
Other specify: type _________________________ Change __________ %∆L/L

Sensitivity Min: _________ %∆L/L Max: ___________ %∆L/L
Status

(Undetect, Detect, Open circuit, Short circuit or Indeterminate)

Time since last retune: ___________ days _____________ hours

:________________________________

(Use the maximum sensitivity reading from

Reason for Retune

%∆L/L (typical)

: _________________________________________________________________

(Reset: manual or power failure, Short circuit, Open circuit, Indeterminate, Inductance change of greater than 15

Crosstalk

(Pass / Fail)

Frequency 1:___________kHz Frequency 2:______________kHz

: _______________ If fail actual frequencies of the two problem detector loops

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