Nortech PD230TD236 User Manual

herein are

subject to alterations without notice.

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]
E-mail: [e-mail] URL: www.nortech.co.za

PD230 Enhanced

NORTECH INTERNATIONAL (PTY) LTD
All rights reserved.
Copyright © 2009
Document No.: 302UM0017_01a
Date of issue: August 2010

In accordance with the manufacturer’s policy of continually updating and improving design, specifications contained

Vehicle Detector

USER MANUAL

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

Table of Contents

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

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

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

2.2 Electrical Data............................................................................................................................6

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 ..........................................................................................................................9

3.2.3 Automatic Sensitivity Boost.............................................................................................10

3.2.4 Presence Time ................................................................................................................10

3.2.5 Pulse / Presence .............................................................................................................10

3.2.6 Reset Switch ...................................................................................................................10

3.3 Internal Link Selection..............................................................................................................11

3.4 Power Fail (Option)..................................................................................................................11

3.5 Front Panel Indicators..............................................................................................................11

4. PRINCIPLE OF OPERATION..................................................................................................13

4.1 Detector Tuning........................................................................................................................13

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

4.3 Modes of Operation .................................................................................................................14

4.3.1 Presence Mode ...............................................................................................................14

4.3.2 Pulse Mode......................................................................................................................14

4.3.3 AB Logic Presence Mode (Barrier Operation) ................................................................15

4.3.4 AB Logic Pulse Mode (Counting Logic) ..........................................................................17

4.4 Response Times......................................................................................................................19

5. INSTALLATION GUIDE...........................................................................................................20

5.1 Product Safety Requirements..................................................................................................20

5.2 Operational Constraints ...........................................................................................................20

5.2.1 Environmental Factors to Consider.................................................................................20

5.2.2 Crosstalk..........................................................................................................................21

5.2.3 Reinforcing ......................................................................................................................21

5.3 Loop and Feeder Material Specification ..................................................................................21

5.4 Sensing Loop Geometry ..........................................................................................................22

5.5 Loop Installation.......................................................................................................................22

6. CONFIGURATION...................................................................................................................25

6.1 PD231 Enhanced Detector : English .......................................................................................25

6.2 PD232 Enhanced Detector: English ........................................................................................26

6.3 PD234 Enhanced Detector: English ........................................................................................26

7. APPLICATIONS.......................................................................................................................27

8. CUSTOMER FAULT ANALYSIS .............................................................................................28

8.1 Fault Finding ............................................................................................................................28

8.2 DU100 – Detector Diagnostic Unit...........................................................................................29

8.2.1 Interpretation of the DU 100 readings.............................................................................29

8.2.1.1 Frequency.........................................................................................................................29

8.3 Functional Test.........................................................................................................................31

APPENDIX A - FCC ADVISORY STATEMENT .............................................................................32

APPENDIX B – INSTALLATION OUTDOORS...............................................................................33

Appendix B.1 IEC 60950-22:2005 – Outdoor cabinet ..............................................................33

Appendix B.2 IEC 60950-22:2005 - Northern Europe..............................................................33

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Appendix B.3 IEC 60950-1:2005 – Overvoltage Category.......................................................33

APPENDIX C - REQUEST FOR TECHNICAL SUPPORT FORM .................................................34

302UM0017 Rev 01 PD230 Enhanced Detector User Manual Page 3 of 37

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!

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.

302UM0017 Rev 01 PD230 Enhanced Detector User Manual Page 4 of 37

1. INTRODUCTION

The “PD230 Enhanced Two Channel Inductive Loop Vehicle Detector” is a dual
channel microprocessor based detector designed specifically for parking and vehicle access control
applications. The PD230 Enhanced detector has been designed using the latest technology in order
to meet the requirements of a vast number of parking applications in terms of operating conditions.
A number of internal functional options are 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 around the popular PD130 series of single channel detectors for
ease of installation and convenience. The various modes are selected by changing the position of
switches on the front of the unit.

The detector oscillator is multiplexed to eliminate any possibility of crosstalk between the loops
connected to the detector.

The switches allow for different loop frequency settings, sensitivity settings and mode settings.
The unit has a number of internally selectable options for configuration of the relay outputs.

The PD230 Enhanced 2 Channel Vehicle Detector provides visual outputs (LED) on the front of the
enclosure and relay change-over contacts at the 11 pin connector at the rear of the enclosure. The
power LED indicates that the unit has been powered. The channel status LED’s below indicate that
a vehicle is present over the loop and when there is a fault on the loop. The Presence relays are
normally fail-safe and will close on a vehicle detect, loop failure or in the event of a power failure.

Available is an additional Power-fail function which enables a short (of up to ten minutes) power-fail,
to have no effect on the operation of the detector when power is restored. The detector will revert to
the same state as prior to power failure, when power is restored.

For additional information refer to the following documents:

Data Sheet - PD230 Enhanced 2 Ch Vehicle Detector Document No. 302DS0002
Installation Leaflet Document No. 879LF0006
Diagnostic Unit DU100 User Manual Document No. 895UM0001

2/4 Ch Vehicle Detector Installation Guide Document No. 879LF0006

302UM0017 Rev 01 PD230 Enhanced Detector User Manual Page 5 of 37

2. TECHNICAL DATA

2.1 Functional Data

Tuning Fully automatic
Self-tuning range 20 to 1000 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 selectable:
Frequency dependent on loop size

Automatic Sensitivity Boost Switch selectable
Modes Output relays may operate in the Presence ( fail-safe ),

Pulse or Direction logic modes
Presence Time Switch selectable:

Limited presence
Permanent presence

Pulse Output Duration 150/250 millisecond options
Response Times 100 milliseconds
Drift Compensation Rate Approx. 1% ∆ L/L per minute
Visual Indication 1 x Power LED - Red

2 x Channel Status LEDs - Green
Relay Outputs 2 x Relays, User Configurable as Presence or Pulse outputs,

Reset Reset by push button on front of enclosure
Surge Protection Loop isolation transformer, gas discharge tubes,

and Zener diode clamping on loop input
Power Fail (Option) 10 minutes memory retention of detector state on power failure.

2.2 Electrical Data

Power requirements 120V AC ± 10% 48 to 62Hz (PD231 models)
230V AC ± 10% 48 to 62Hz (PD232 models)
PD231 and PD232 models: 1.5 VA Maximum at 230V

Normally Open (N/O) contacts
(Opto-Isolated Outputs are available on request. MOQ applies)

12V - 10% to 24V + 10% DC/AC 48 to 62Hz (PD234 models)

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Relay Contact Rating 2 x Relays rated - 5A @ 230 VAC

Opto-Isolated Output rating 33 V 50 mA

2.3 Environmental Data

Storage Temperature -40°C to +85°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 IP 30. - This product MUST be installed in an enclosure

PD234 models: 1 VA Maximum at 12V

For ambient temperatures above 60 °C De-rate the
relay maximum current as per graph below

Note - Opto-Isolated Outputs are available on request. MOQ

applies

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2.4 Mechanical Data

Housing material ABS blend
Mounting Position Shelf or DIN rail mounting
Connections 11-pin submagnal type ( JEDEC No. B11– 88 )
Size of Housing 78mm ( High ) x 41mm ( Wide ) x 80mm ( Deep )

80 mm

77.7 mm

75.9 mm

2.5 Approvals

C.E. Regulations EN 301 489-3 Equipment Type: III

Class of Equipment: 2

EN 50293 Performance Criteria B

Safety: IEC / EN 60950-1

40.6 mm

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3. OPERATING INSTRUCTIONS

3.1 Hardware Set-up

The PD230 Enhanced dual channel parking detector is 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

Where more than one detector is used at the same site, the
detectors must be set-up to ensure that there is no CROSSTALK
(interference) between adjacent loops connected to different
detectors.

For more information about crosstalk refer to section 5.2.2.
The frequency switches are the lower two switches, numbered 1

and 2. There are four frequency selections and are set as follows:

As a general rule, the detector connected to the inductive loop with the greatest inductance should
be set to operate at the lowest frequency.

When the frequency switch setting is altered, the operating frequency of both detector channels will
shift. Because the unit has a common oscillator and the multiplexer connects the loops alternatively
to this oscillator.

3.2.2 Sensitivity

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

The frequency switches allows the operating frequencies of the
detector to be shifted higher or lower depending on the switch
setting.

The operating frequency of the detector channel is determined by:

The operating frequency of the detector channel increases as the
loop inductance decreases and vice versa.

The inductance of the loop and feeder cable is determined by:

S1 S2

Off Off High frequency
Off On Medium-High frequency
On Off Medium-Low frequency
On On Low frequency

Inductance of the loop and feeder cable
Detector frequency switch settings

Size of the loop
Number of turns in the loop
Length of feeder cable

Frequency Setting

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Channel1 Channel 2
S6 S5 S4 S3

Off Off Off Off High
On Off On Off Medium-High
Off On Off On Medium-Low
On On On On Low

3.2.3 Automatic Sensitivity Boost

Automatic sensitivity boost is a mode which alters the undetect level of the detector. This mode is
selected by switch No. 7 on the front of the enclosure and is set as follows: -

S7

Off Disabled
On Enabled

Automatic sensitivity boost causes the sensitivity to be boosted to a maximum on detection of the
vehicle, and maintained at this level during the presence of the entire vehicle over the loop. When
the vehicle departs the loop and detection is lost the sensitivity reverts to the pre-selected level.

3.2.4 Presence Time

The presence time may be set to permanent presence or to limited presence. In permanent
presence mode the detector will continuously compensate for all environmental changes whilst there
is a vehicle present over the loop. In limited presence mode there will be a finite time that the
detector will remain in detect. This time is dependent on the change of inductance that the vehicle
caused. The presence mode is set with switch No. 8 and is set as follows: -

S8
Off Limited Presence
On Permanent Presence

3.2.5 Pulse / Presence

The channel’s relay may be set to either Pulse Mode or Presence Mode with switches No. 9 & No.
10 as shown in the table below: -

Channel1 Channel 2

S10 S9

Off Off Presence
On On Pulse

3.2.6 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
the automatic tuning cycle.

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3.3 Internal Link Selection

WARNING - ONLY SERVICE PERSONNEL MAY OPEN THE UNIT

TO CHANGE INTERNAL SETTINGS!

There is one 3 way link located inside the PD230 Enhanced detector housing, which is used to alter
the mode of operation of the detector. The link has been placed inside the unit to avoid incorrect
operation due to selection by an unauthorised operator.

For a description of the AB Logic mode refer to section 4.3 “Modes of Operation” below
For the PD230 Enhanced parking detector, the default setting for both channel output relays is

presence mode (Front panel switches 9 & 10 OFF) with no AB logic (i.e. no jumper on LK1).

3.4 Power Fail (Option)

Power-Fail-Option is available on request. MOQ applies

The detector (with Power-Fail Option) is able to retain the output state for a power failure of not
greater than 10 minutes. Thus, when the power is restored, the detector will not re-tune but return to
the detect state prior to the power failure. If a vehicle was on the loop during power failure, it will
remain detected when power is restored.

3.5 Front Panel Indicators

While the detector is tuning, the Channel LED will indicate the “mode” status of the detector.
i) Any Channel output operating in the presence or pulse modes will come on and extinguish when

the system is tuned.
ii) When the AB Logic mode is selected, the Channel LED’s will alternatively flash slow and

extinguish when the system is tuned.
If a loop fault exists the Channel LED will come on and flash indicating a fault. If the fault is self-

healing the detector will continue to operate and the LED will continue to show the historical fault.
The detector must be reset or power removed to clear the historical fault information.

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

The Power LED at the top of the unit will remain on to indicate that the unit is powered. This LED is
also used as the link to the diagnostic unit ( DU100 ).

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4. PRINCIPLE 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 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 detection 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. The detector will re-tune if any of the following events
occur:-

- When power is applied to the detector.

- A detector reset is initiated via the reset button.

- A detect of greater than 15% ∆ L/L occurs.

The detector will automatically tune each channel to its connected loop. The detector will tune to any
loop in the inductance range of 20 to 1000 micro henries.

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.

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.

The nature of the application determines the required sensitivity, which may be adjusted by means
of the front panel controls.

Sensitivity levels on the PD230 Enhanced detector have been carefully optimised for parking and
vehicle access control applications. The detection of small, unwanted objects such as bicycles and
trolleys can be eliminated by selecting lower sensitivity levels, whilst high-bed vehicles and
vehicle/trailer combinations will not loose detection by using the Automatic Sensitivity Boost (ASB)
option.

ASB operates as follows. When ASB is disabled the undetect level is dependent on the sensitivity
setting of the detector. Hence as the detector is made less sensitive, the undetect level will be

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reduced accordingly. When the ASB is enabled the undetect level will always be the
same irrespective of the sensitivity setting and will be equivalent to the undetect
level when the sensitivity is on maximum setting.

4.3 Modes of Operation

The PD230 Enhanced Detector may be configured for any one of the following modes:

Presence Mode
Pulse Mode
AB Logic Presence Mode (Barrier Operation)
AB Logic Pulse Mode (Counting Logic)

4.3.1 Presence Mode

Link LK1 open

To set Channel 1 to Presence mode switch OFF switch 10
To set Channel 2 to Presence mode switch OFF switch 9

In the presence mode the detector channels operate independently

In the presence mode the detector will give a continuous output during the presence of a
vehicle over the inductive loop. As the detector is designed with the permanent presence
feature, the detector will indicate vehicle presence for an unlimited period of time.

The presence outputs are known as fail-safe outputs. This implies that in the event of a
power failure or loop failure the detector will give detect outputs. (Fail-Secure Presence
Mode is available on request. MOQ applies)

If permanent presence is not selected, then the detect time will be dependent on the change
of inductance. The presence time on the limited presence setting will be approximately 1
hour for an inductance change of 3% ∆ L/L.

4.3.2 Pulse Mode

Link LK1 open

To set Channel 1 to Pulse mode switch ON switch 10
To set Channel 2 to Pulse mode switch ON switch 9

In the pulse mode the detector channels operate independently.

In the pulse mode the detector will give a pulse of 150 millisecond duration, when a vehicle
enters the loop (Pulse on Detect) (a pulse of 250 millisecond is available on request. MOQ
applies).

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(Pulse on un-detect is available on request. MOQ applies)

4.3.3 AB Logic Presence Mode (Barrier Operation)

Internal link LK1 shorted from Pin 1 to Pin 2. In this mode switches 9 & 10 are ignored.

AB LOGIC Presence Mode is a direction logic mode, and is capable of determining direction
of travel of a vehicle. Two loops are laid in the direction of travel to provide the input for this
mode.

If a vehicle enters Channel 1 Loop and then proceeds to Channel 2 Loop, Channel 1 relay
contacts will close for the duration of that the vehicle is over Channel 2 Loop.

If a vehicle enters Channel 2 Loop and then proceeds to Channel 1 Loop, Channel 2 relay
contacts will close for the duration of that the vehicle is over Channel 1 Loop.

Progress of a vehicle over the loops
Case 1:

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Exits Loop 1,
C - Vehicle Enters Loop2,
D - Vehicle Exits Loop 2,

(AB LOGIC Presence Mode)

Typically caused by loops
being too far apart or very
small vehicles

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Case 2:

(AB LOGIC Presence Mode)

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Enters Loop2
C - Vehicle Exits Loop 1
D - Vehicle Exits Loop 2

This is the correct forward
operation for Presence
AB Logic

Case 3:

(AB LOGIC Presence Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Exits Loop 2
C - Vehicle Enters Loop1
D - Vehicle Exits Loop 1

Typically caused by loops
being too far apart or very
small vehicles

Case 4:

(AB LOGIC Presence Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Enters Loop1
C - Vehicle Exits Loop 2
D - Vehicle Exits Loop 1

This is the correct reverse
operation for Presence
AB Logic

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Case 5:

(AB LOGIC Presence Mode)

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Enters Loop2
C - Vehicle Starts to reverse
D - Vehicle Exits Loop 2
E - Vehicle Exits Loop 1

This case should not
happen but it does
occasionally

Case 6:

(AB LOGIC Presence Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Enters Loop1
C - Vehicle Starts to reverse
D - Vehicle Exits Loop 1
E - Vehicle Exits Loop 2

This case should not
happen but it does
occasionally

4.3.4 AB Logic Pulse Mode (Counting Logic)

Internal link LK1 shorted from Pin 2 to Pin 3. In this mode switches 9 & 10 are ignored.

AB LOGIC Pulse Mode is a direction logic mode, and is capable of determining direction of
travel of a vehicle. Two loops are laid in the direction of travel to provide the input for this
mode.

This mode is used to activate equipment requiring vehicle direction inputs such as automatic
fee collection equipment, vehicle counters, or warning devices in one-way systems.

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If a vehicle enters Channel 1 Loop and then proceeds to Channel 2 Loop, a
150 ms pulse will be issued on Channel 1 relay output as the vehicle leaves
Channel 1 Loop.

If a vehicle now enters Channel 2 Loop and then proceeds to Channel 1 Loop, a 150 ms
pulse will be issued on Channel 2 relay output as the vehicle leaves Channel 2 Loop.

Progress of a vehicle over the loops
Case 1:

(AB LOGIC Pulse Mode)

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Exits Loop 1,
C - Vehicle Enters Loop2,
D - Vehicle Exits Loop 2,

Typically caused by loops
being too far apart or very
small vehicles

Case 2:

(AB LOGIC Pulse Mode)

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Enters Loop2
C - Vehicle Exits Loop 1
D - Vehicle Exits Loop 2

This is the correct forward
operation for Pulse
AB Logic

Case 3:

(AB LOGIC Pulse Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Exits Loop 2
C - Vehicle Enters Loop1
D - Vehicle Exits Loop 1

Typically caused by loops
being too far apart or very
small vehicles

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Case 4:

(AB LOGIC Pulse Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Enters Loop1
C - Vehicle Exits Loop 2
D - Vehicle Exits Loop 1

This is the correct reverse
operation for Pulse
AB Logic

Case 5:

(AB LOGIC Pulse Mode)

Forward direction
A - Vehicle Enters Loop1

B - Vehicle Enters Loop2
C - Vehicle Starts to reverse
D - Vehicle Exits Loop 2
E - Vehicle Exits Loop 1

Forward direction.
This case should not
happen but it does
occasionally

Case 6:

(AB LOGIC Pulse Mode)

Reverse direction
A - Vehicle Enters Loop2

B - Vehicle Enters Loop1
C - Vehicle Starts to reverse
D - Vehicle Exits Loop 1
E - Vehicle Exits Loop 2

Reverse direction.
This case should not
happen but it does
occasionally

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 on that channel.

The response times of the PD230 Enhanced Detectors has been adjusted to prevent false operation
in electrically noisy environments, but retains adequate response to vehicles in parking and vehicle
access 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 by 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

• i) WARNING: The unit must be EARTHED.

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

• iii) WARNING: On 120 Vac and 230 Vac models, a readily accessible disconnect

device must be incorporated into the mains wiring (as per EN60950-1:2005
Section 1.7.2.2).

• iv) 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 60950-1:2005 section 1.7..2.3) typically this will be a 5 Amp
Magnetic Circuit Breaker for AC models and a fuse for DC models.

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

• vi) WARNING: No user serviceable parts inside.

ONLY SERVICE PERSONNEL MAY OPEN THE UNIT TO CHANGE
INTERNAL SETTINGS

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

As an alternative to the 11 pin relay base, Nortech has a 11 pin wiring
harness, Nortech Part No. 302FT0041, which can only be used in SELV
voltage (less than 60 V dc or less than 42 V ac) applications.

5.2 Operational Constraints

5.2.1 Environmental Factors to Consider

Even though the PD230 Enhanced 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 PD230 Enhanced parking detectors are rated to operate at from – 40°C to +70°C 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.

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5.2.2 Crosstalk

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

Should the loops be connected to the same dual channel detector crosstalk will not occur, due to the
fact that sequential polling of the loops takes place, resulting in only one loop being energised at a
given time.

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 electrical cables.

The screen must be earthed at the detector end only.

4. Running feeder cables in their own slots, separated by at least 300 mm.

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 5.3.

The ideal minimum spacing between the loop and the cable and steel reinforcing is 150mm,
although this is not always practically possible. The slot depth should be kept as shallow as
possible, taking care that no part of the loop or the feeder remains exposed after the sealing
compound has been applied.

5.3 Loop and Feeder Material 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
minimise 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 not be 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 angles to the direction of traffic movement. These sides
should ideally be 1 metre apart.

Loops operating from the same detector module can share a common slot along one of the longer
sides, if so required. This type of configuration could be applied in a direction logic application. The
maximum separation permitted for this application is 1 metre, ensuring that a vehicle can straddle
both loops simultaneously in the required direction of travel.

The only factor which governs maximum separation between loops in all other applications is the
feeder length, with 100 metres being the maximum recommended length.

The length of the loop will be determined by the width of the roadway to be monitored. The loop
should reach to within 300 mm 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.
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. MKT0001.

• “TRAFFIC DETECTION” - Nortech Doc. No. MKT0002.

• “PARKING APPLICATIONS MANUAL” - Nortech Doc. No. MKT0003.

• “LOOPS and LOOP INSTALLATION” – Nortech Doc. No. MKT05

5.5 Loop Installation

All permanent loop installations should be installed in the roadway by cutting slots with a masonry
cutting disc or similar device. 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

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