Honeywell Sensepoint XCD RFD User manual

Technical Manual
Sensepoint XCD RFD (Remote Flammable Detector)
Technical Manual

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
2
1 Safety
Ensure that this Operating Manual is read and understood BEFORE installing / operating
/ maintaining the equipment. Pay particular attention to Warnings and Cautions. All
document Warnings are listed here and repeated where appropriate at the start of the
relevant chapter(s) of this Operating Manual. Cautions appear in the sections/sub-sections
of the document where they apply
WARNINGS
Sensepoint XCD RFD is designed for installation and use in Class I, Division 1, Groups B,C
& D Hazardous Areas in the Americas.
Installation must be in accordance with the recognized standards of the appropriate
authority in the country concerned.
Access to the interior of the detector, when carrying out any work, must only be conducted
by trained personnel.
Before carrying out any work ensure local regulations and site procedures are followed.
Appropriate standards must be followed to maintain the overall certication of the detector.
If using an anti-seize compound, the threads should be thinly coated with an approved
silicone free compound e.g. petroleum jelly
To reduce the risk of ignition of hazardous atmosphere, de-classify the area or disconnect
the equipment from the supply circuit before opening the detector enclosure. Keep
assembly tightly closed during operation.
Never attempt to open a junction box/enclosure or replace/ret the sensor in potentially
hazardous atmospheres while power is still applied to the transmitter.
The detector must be earthed/grounded for electrical safety and to limit the effects of radio
frequency interference. Earth/ground points are provided inside and outside the unit. The
internal grounding shall be used as the primary equipment ground. The external terminal is
only a supplemental bonding connection where local authorities permit or require such a
connection.
Ensure that all screens/instrument earth/clean earth wiring is earthed/grounded at a single
point (either at the controller or detector - BUT NOT BOTH) to prevent false readings or
alarms that may occur due to potential earth/ground loops.
Take care when handling sensors as they may contain corrosive solutions.
Do not tamper with or in any way disassemble the sensor.
Do not expose to temperatures outside the recommended ranges.
Do not expose sensors under storage conditions to organic solvents or ammable liquids.
This equipment is designed and constructed as to prevent ignition sources arising, even
in the event of frequent disturbances or equipment operating faults. Note: The control card
must have a suitably rated fuse.
The sensor head must be tted with the supplied weather protection, and mounted so that
the sinter is pointing downward to provide ingress protection IPX6.
The weather protection is a potential electrostatic charging hazard. The manufacturer’s
instructions should be observed.
The Sensepoint sensor is a possible Electrostatic risk - Do not rub or clean with solvents.
Clean with a damp cloth. High velocity airows and dusty environments can cause
hazardous electrostatic charges.
Refer to the Sensepoint XCD RFD Control Drawing 3001EC091 shown in section 17.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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2 Information
This manual is for use with the Sensepoint XCD RFD range transmitters only.
The Start-up/Surge/In rush current is dependant on the type of power supply used. The
typical start-up current for Sensepoint XCD RFD is less than 800mA. Measure the start-
up current using the specic power supply before installation to ensure suitability for your
application.
Honeywell Analytics can take no responsibility for installation and/or use of its equipment if
not done so in accordance with the appropriate issue and/or amendment of the Technical
Manual.
The reader of this Operating Manual should ensure that it is appropriate in all details
for the exact equipment to be installed and/or operated. If in doubt, contact Honeywell
Analytics for advice.
The following types of notices are used throughout this Operating Manual:
WARNING
Identies a hazardous or unsafe practice which could result in severe injury or
death to personnel.
Caution: Identies a hazardous or unsafe practice which could result in minor injury
to personnel, or product or property damage.
Note: Identies useful/additional information.
Every effort has been made to ensure the accuracy of this document; however, Honeywell
Analytics can assume no responsibility for any errors or omissions in this document or
their consequences.
Honeywell Analytics would greatly appreciate being informed of any errors or omissions
that may be found in the content of this document.
For information not covered in this document, or if there is a requirement to send
comments/corrections about this document, please contact Honeywell Analytics using the
contact details given on the back page.
Honeywell Analytics reserve the right to change or revise the information supplied
in this document without notice and without obligation to notify any person or
organization of such revision or change. If information is required that does not
appear in this document, contact the local distributor/agent or Honeywell Analytics.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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3 Table of contents
1 Safety................................................................................................................................2
2 Information.......................................................................................................................3
4 Introduction......................................................................................................................6
4.1 Transmitter..................................................................................................................7
4.2 Flammable Gas sensors.............................................................................................7
4.2.1 705 LEL Flammable gas sensors (cCSAus Approved)............................................8
4.3 Accessories.................................................................................................................9
4.4 Options .....................................................................................................................10
4.4.1 Modbus®...............................................................................................................10
5 Installation .....................................................................................................................12
5.1 Mounting and location...............................................................................................13
5.2 Mounting the transmitter ...........................................................................................13
5.3 Installing the sensor..................................................................................................14
6 Electrical connections .................................................................................................15
6.1 Transmitter Wiring.....................................................................................................16
6.2 Terminal connections ................................................................................................17
6.3 Power........................................................................................................................18
6.4 Cabling......................................................................................................................19
6.5 Cable and Earth/Ground regimes .............................................................................19
6.6 Ground Terminal Wiring ............................................................................................20
7 Default conguration ....................................................................................................21
8 Normal Operation ..........................................................................................................22
8.1 Display Screen..........................................................................................................22
8.2 System Status...........................................................................................................23
8.3 Magnetic Wand Activation.........................................................................................24
8.4 Operation Mode Structure ........................................................................................24
9 First time switch on (Commissioning) ........................................................................25
10 Response Check and Calibration ..............................................................................27
10.1 Zeroing and span calibration .................................................................................27
11 General Maintenance...................................................................................................31
11.1 Operational Life.......................................................................................................31
12 Servicing ......................................................................................................................32
12.1 Sensor replacement................................................................................................32
12.2 Replacing Modules within the Transmitter ..............................................................34
12.3 Faults and Warnings ...............................................................................................35
13 Menu’s and Advanced Conguration ........................................................................36
13.1 Abort Function.........................................................................................................36
13.2 Conguration Mode ................................................................................................36
13.2.1 Conguration mode operation table.....................................................................40
13.3 Sensor / Gas Selection ...........................................................................................42
13.3.1 Sensor Selection..................................................................................................42
13.3.2 Gas Selection ......................................................................................................42
13.4 Review Mode ..........................................................................................................44

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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14 General specication ................................................................................................. 47
15 Ordering information.................................................................................................. 48
16 Warranty statement .................................................................................................... 50
17 Installation Drawing ................................................................................................... 51
17.1 Mechanical Installation Drawing ........................................................................... 51
17.2 Electronic Connection Drawing.............................................................................. 52
17.3 Duct Mounting Drawing ......................................................................................... 53
17.4 Collecting Cone Drawing ....................................................................................... 54
17.5 Mounting Bolt Assy Drawing .................................................................................. 55
17.6 Mounting Bracket Drawing..................................................................................... 56
17.7 Control Drawing ..................................................................................................... 57
18 Certication................................................................................................................. 59
18.1 North America cCSAus .......................................................................................... 59
18.2 Inmetro Certicates................................................................................................ 64
18.3 cCSAus Transmitter Name Plate ........................................................................... 70
19 Cross Interference and Cross Calibration ............................................................... 71
19.1 Cross Calibration Flammable Gas Detector .......................................................... 71
A.1 Modbus and the XCD .............................................................................................. 74
A.2 Modbus Registers ................................................................................................... 75

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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Locking
Grub
screw
Internal Earth
Point
Enclosure
External Eart
h
Point (x2)
M20 or 3/4"NPT cable/conduit
entry (x2)
Cover
Seal
Display Module
Terminal Module
Ex d Plug
Integral
mounting plate
Certification Label
M25 or 3/4"NPT entry for Flammable
Sensor or Remote Sensor Cable Gland
4 Introduction
The Sensepoint XCD RFD transmitter allows the user to either directly or remotely mount
a flammable gas sensor from the Sensepoint XCD. See sensor information in section
4.2. The remote sensor can be located up to 30 meters (100 feet) from the transmitter.
The transmitter features a display and three programmable relays for controlling external
equipment e.g. alarms, sirens, valves or switches. The transmitter provides an industry
standard 3-wire, 4-20mA source or sink output for connection to a dedicated gas detection
control system or PLC.
The construction of Sensepoint XCD RFD allows it to be used in hazardous area locations;
it may also be used in other areas not classied as hazardous. Sensepoint XCD RFD is
suitable for use in Class I Division 1 areas.
Calibration and maintenance is carried out using a Magnetic Wand, this allows a single
user to undertake routine maintenance without needing to access internal components.
Sensepoint XCD RFD comprises of the main parts as shown below.
Diagram 1. – Exploded View

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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4.1 Transmitter
The transmitter enclosure has three threaded entries. The two cable entries either side
of the upper part of the transmitter housing are for connecting the power source, signal
output and relay contacts to associated signalling equipment. The bottom entry allows
local (direct) mounting of the appropriate sensor. These three entries are ¾” NPT for the
Americas.
A local LCD provides gas type, concentration, alarm and operating status. The display
provides numerical, bar graph and icon information.
Diagnostic information may also be displayed when the transmitter is interrogated using
a magnet. The transmitter cover has a glass window which allows use of the Magnetic
Wand to activate the three user interface magnetic switches that are located on the front
of the display module. The magnet also enables a non intrusive, one-man calibration and
conguration facility for the Sensepoint XCD RFD.
4.2 Flammable Gas sensors
The Sensepoint XCD/RFD Transmitter is designed to work with the following ammable
gas sensor types described in below sections 4.2.1, 4.2.2 and 4.2.3. Sensepoint XCD
sensors use electro-catalytic technologies. The Sensepoint XCD RFD is cCSAus approved
for use in North America.
Please refer to chapter 15 ‘Ordering information’ for more detail information.
Diagram 2: Sensepoint XCD RFD Display and Magnetic Switches
Measuring
Units
InhibitIcon
Test Pass Icon
Warning
FaultIcon
Magnetic Wand
activation Icon
Gas Type
Magnetic
MENU/ENTER
Switch
Magnetic
UP Switch
Magnetic
DOWN
Switch
Gas Reading
Bar Graph
Alarm Icon
Full Scale
Calibration Icon
XCD RFD

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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4.2.1 705 LEL Flammable gas sensors (cCSAus Approved)
Standard LEL version
The standard LEL sensor is available for use in temperatures up to 80°C (remote mounting
only) and detects gas concentrations up to 100% LEL of a target gas with a resolution in
the region of 1% LEL, depending on the gas being detected. The sensor is available with
¾”NPT thread only. The standard 705 is both CSA and UL approved.
High Temperature LEL version
The high temperature version(UL approved) is available for use in temperatures up to
150°C (remote mounting only) and detects gas concentrations up to 100% LEL of a target
gas with a resolution in the region of 1% LEL, depending on the gas being detected. The
sensor is available with ¾”NPT thread only. The 705 HT is UL approved only.
Details for connecting these sensors with the Sensepoint XCD RFD transmitter are
provided in sections 5 and 6. For more sensor specific details, refer to the Technical
Handbook Part No. 2106M0502 or their individual manual (705 Combustible Gas Sensor
Operating Instructions Part No: 00705M5002)
705 Standard LEL version 705 High Temperature LEL version
705 LEL ammable sensors

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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4.3 Accessories
A range of accessories are available to allow use of Sensepoint XCD RFD in a wide
variety of applications. These include Pipe mounting bracket, Sunshade deluge cover,
Sensor collecting cone, Sensor flow Housing and Remote sensor mounting junction
boxes.
Standard Weather Protection
For UL/CSA Junction Box
(P/N: 2430-0021)
For Sensepoint / 705
(P/N: 02000-A-1640/1635)
For Sensepoint / 705
(P/N: 02000-A-1642)
The Standard Weather Protection is designed to
protect the sensor from changes in environmental
conditions. This is recommended to be tted to
a Sensepoint XCD sensor and Sensepint / 705
sensors.
Calibration Gas Flow Housing
The Calibration Gas Flow Housing (P/N: 02000-
A-1645) may be used for either calibration of the
Sensepoint / 705 sensor or if the Sensepoint /
705 sensor is to be used as part of a Aspirated
Sampling System.
Collecting Cone
Remote Sensor Mounting
Sensepoint Filter and Filter Housing
The Collecting Cone is an optional accessory that
may be tted to the Weather Protection of XCD
and Sensepoint / 705 sensors. The collecting
cone is designed for use with gases that are
lighter than air.
UL/CSA aluminum junction box, (P/N: 2430-0021)
is used for remote sensor mounting. Make
the connection from the junction box to the
transmitter using suitable cable and cable glands.
Sensepoint Stainless steel lter (P/N: 00780-
F-0018) and Filter Housing (P/N: 00780-C-
0038) is an optional accessory can be used to
offer additional protection to the Sinter in dry,
and dusty applications.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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4.4 Options
4.4.1 Modbus®
One of the most common eld buses in the industry, the optional Modbus®interface allows
the XCD to connect to a bus of devices and transmit data to PLCs or controllers (see
Appendix A). Connections to the XCD are made through a pluggable terminal block on
the Modbus®interface circuit board. Modbus®RTU protocol uses ASCII/Hex protocols for
communication. And allows all transmitter/sensor front panel functions to be transmitted
using this industrial eldbus.
Modbus®protocol is a Master-Slaves protocol. Only one master (at the same time) is
connected to the bus and one or up to 32 slave nodes are also connected to the same
serial bus. Modbus®communication is always initiated by the master. The slave nodes will
never transmit data without receiving a request from the master node. The slave nodes
will never communicate with each other. The master node initiates only one Modbus®
transaction at the same time.
The MODBUS may only be used for data collection or record keeping with regard to
combustible gas detection and not for performance verication.
Modbus option is available only for selected gases. Please refer to chapter 15 Ordering
information.
To nd out if a unit has the ModBus option tted, look at the part number on the product
label. Units tted with ModBus have the letter “M” at the end of the part number.
Note: MODBUS®is a registered trademark of Schneider Automation Inc.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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(MODBUS ID SETTING)
Set id>>Set ModBus slave ID>>Set Baud rate>>Set Parity
1) Slave ID shall be set 1~247
2) Baud rate setting 9600 or 19200
3) Parity setting (No, Even, Odd)
From the Conguration Mode screen, select‘’. To set the ModBus Slave ID, use the up-
down ‘’switches to move to the desired position and use ‘’to select it. Again, using
the‘’switches, increment or decrement the value until the desired value appears,
selects the value and moves to the next setting.
The communications baud rate and Parity Setting can also be set from this screen by
using the‘’ switches to navigate to the baud rate display then selecting ‘’. Using the
‘’switches, highlight the proper baud rate or parity setting and select‘’. Default is
Slave ID 1, 19200bps and even parity.
Note: Set ID menu is available only for XCD equipped with Modbus option.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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5 Installation
Refer to the Sensepoint XCD RFD Control Drawing 3001EC091 for CSA applications
shown in section 17.
WARNINGS
Sensepoint XCD RFD is designed for installation and use in Class I, Division 1, Group B,C &
D Hazardous Areas in the Americas.
Installation must be in accordance with the recognized standards of the appropriate
authority in the country concerned.
Access to the interior of the detector, when carrying out any work, must only be conducted
by trained personnel.
Before carrying out any work ensure local regulations and site procedures are followed.
Appropriate standards must be followed to maintain the overall certication of the detector.
If using an anti-seize compound, the threads should be thinly coated with an approved
silicone free compound e.g. petroleum jelly
To reduce the risk of ignition of hazardous atmosphere, de-classify the area or disconnect
the equipment from the supply circuit before opening the detector enclosure. Keep
assembly tightly closed during operation.
Never attempt to open a junction box/enclosure or replace/ret the sensor in potentially
hazardous atmospheres while power is still applied to the transmitter.
The detector must be earthed/grounded for electrical safety and to limit the effects of
radio frequency interference. Earth/ground points are provided inside and outside the unit.
Ensure that all screens/instrument earth/clean earth wiring is earthed/grounded at a single
point (either at the controller or detector - BUT NOT BOTH) to prevent false alarms due to
earth/ground loops.
Take care when handling sensors as they may contain corrosive solutions.
Do not tamper with or in any way disassemble the sensor.
Do not expose to temperatures outside the recommended ranges.
Do not expose sensors under storage conditions to organic solvents or ammable liquids.
This equipment is designed and constructed as to prevent ignition sources arising, even
in the event of frequent disturbances or equipment operating faults. Note: The control card
must have a suitably rated fuse.
The sensor head must be tted with the supplied weather protection, and mounted so that
the sinter is pointing downward to provide ingress protection IPX6.
The weather protection is a potential electrostatic charging hazard. The manufacturer’s
instructions should be observed.
The Sensepoint sensor is a possible Electrostatic risk - Do not rub or clean with solvents.
Clean with a damp cloth. High velocity airows and dusty environments can cause
hazardous electrostatic charges.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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5.1 Mounting and location
Gas detectors should be mounted where a potential hazard of gas is most likely to be
present. The following points should be noted when locating gas sensors.
• When locating detectors consider the possible damage caused by natural events e.g.
rain or ooding.
• Consider ease of access to the gas detector for functional testing and servicing.
• Consider how escaping gas may behave due to natural or forced air currents.
Note: The placement of gas detectors should be determined following the advice of
experts having specialist knowledge of gas dispersion, experts having knowledge of the
process plant system and equipment involved, safety and engineering personnel. The
agreement reached on the location of detectors should be recorded.
5.2 Mounting the transmitter
The Sensepoint XCD RFD transmitter has an integral mounting plate consisting of four
mounting holes on the transmitter body. The transmitter may be xed directly to a surface
mounting, or to a horizontal or vertical pipe/structure, 40.0-80.0mm (1.6 to 3.1 inches) in
diameter/cross section. The Pipe Mounting Bracket accessory (optional accessory) may
be used for this purpose.
Caution: The location of gas detectors should be made in accordance with any relevant
local and national legislation, standards or codes of practice. Always replace sensors
with a sensor of the same type.
Diagram 5: Outline and mounting dimensions
All dimensions are shown in mm.
¾”NPT entries for
UL / CSA
Versions

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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5.3 Installing the sensor
WARNINGS
If using an anti-seize compound, the threads should be thinly coated with an approved
silicone free compound e.g. petroleum jelly
Take care when handling old sensors as they may contain corrosive solutions.
Take care when removing or replacing the Sensor Retainer as there may be sharp edges
present on the adjoining threads.
The equipment is designed and constructed as to prevent ignition sources arising, even in
the event of frequent disturbances or equipment operating faults.
The sensor head must be tted with the supplied weather protection, and mounted so that
the sinter is pointing downward to provide ingress protection IPX6.
The weather protection is a potential electrostatic charging hazard. The manufacturer’s
instructions should be observed.
A remotely mounted sensor should be mounted using a suitable junction box . For further
details regarding mounting sensors to suitable junction boxes refer to the relevant sensor
manual.
1. Connect the remote sensor/junction box to the Sensepoint XCD RFD transmitter
using suitable cable with wires of diameter 0.5 ~ 2.5mm2 (20AWG ~ 13AWG).
2. Connect the cable to the transmitter enclosure via the bottom entry.
3. Cable based installation in many countries including Europe must use appropriately
certified cable glands and refer to the Sensepoint XCD RFD Control Drawing
3001EC091 shown in section 17 for conduit based installation in the Americas.
Note: The maximum cable length between the remotely mounted sensor and the
Sensepoint XCD RFD transmitter is 30 meters (100 feet).
4. Terminate the wires from the sensor in the transmitter as shown in chapter 6.2.
5. Select sensor type at conguration menu after remote sensor mounting. Refer to the
chapter 12.1 Sensor Replacement and the chapter 13.3.1 Sensor Selection.
Cable Gland Sensor
Transmitter
Junction Box
Sensepoint XCD RFD with Sensepoint Remote Sensor

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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6 Electrical connections
WARNINGS
Sensepoint XCD RFD is designed for installation and use in Class I, Division 1, Group B,C &
D Hazardous Areas in the Americas.
Installation must be in accordance with the recognized standards of the appropriate
authority in the country concerned.
Access to the interior of the detector, when carrying out any work, must only be conducted
by trained personnel.
Before carrying out any work ensure local regulations and site procedures are followed.
Appropriate standards must be followed to maintain the overall certication of the detector.
If using an anti-seize compound, the threads should be thinly coated with an approved
silicone free compound e.g. petroleum jelly
To reduce the risk of ignition of hazardous atmosphere, de-classify the area or disconnect
the equipment from the supply circuit before opening the detector enclosure. Keep
assembly tightly closed during operation.
Never attempt to open a junction box/enclosure or replace/ret the sensor in potentially
hazardous atmospheres while power is still applied to the transmitter.
The detector must be earthed/grounded for electrical safety and to limit the effects of
radio frequency interference. Earth/ground points are provided inside and outside the unit.
Ensure that all screens/instrument earth/clean earth wiring is earthed/grounded at a single
point (either at the controller or detector - BUT NOT BOTH) to prevent false alarms due to
earth/ground loops.
Take care when handling sensors as they may contain corrosive solutions.
Do not tamper with or in any way disassemble the sensor.
Do not expose to temperatures outside the recommended ranges.
Do not expose sensors under storage conditions to organic solvents or ammable liquids.
The Sensepoint sensor is a possible Electrostatic risk - Do not rub or clean with solvents.
Clean with a damp cloth. High velocity airows and dusty environments can cause
hazardous electrostatic charges.
Refer to the Sensepoint XCD RFD Control Drawing 3001EC091 shown in section 17.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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6.1 Transmitter Wiring
The Sensepoint XCD RFD transmitter may be wired in either Current SOURCE or Current
SINK conguration. These two options are offered to allow greater exibility in the type of
control system that it can be used with. SOURCE/SINK is selectable via the switch located
on the back side of the display module; accessible by removing the display module during
installation / commissioning (see section 9).
Caution: All electrical connections should be made in accordance with any relevant
local or national legislation, standards or codes of practice.
Caution: 250ohm load resistor (RL) is installed in the factory, in case of connection
with controller, this resistor should be removed because controller has load resistor
internally.
Note: Terminate cable screen at detector or controller, not both.
XCD Source 3 Wire 4-20mA (Source)
XCD Sink 3 Wire 4-20mA (Sink)
Controller
+VE
Signal
1
2
3
Detector
+VE
Signal
-VE
R
L
-VE
1
3
2
Controller
+VE
Signal
1
2
3
Detector
+VE
Signal
-VE
R
L
-VE
1
3
2
R
L
Controller
+VE
Signal
1
2
3
Detector
+VE
Signal
-VE -VE
1
3
2
R
L
Controller
+VE
Signal
1
2
3
Detector
+VE
Signal
-VE -VE
1
3
2

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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6.2 Terminal connections
Note: Ensure that none of the wires in the terminal area cause an obstruction when
retting the Display Module. Ensure that the socket on the Display Module is fully engaged
in the Display Module Connector on the Terminal Module.
Diagram 6: Sensepoint XCD RFD Terminal module
Terminal Block
Ground/Earth
Point
Power & Signal
Display Module
Connector
Display Module
Alignment Pin
Locator
Terminal Block
for Relays
Terminal block for
Sensepoint or 705
Flammable sensor
Note: Terminal
Blocks are
plug/socket type
and may be
removed to ease
wiring.
Terminal Module Connections
Terminal
Number Marking Connection Description
1 24V +VE Supply(16-32VDC)
Controller Connections
2 0V -VE Supply(0VDC)
3 4~20mA Current Output Signal
4 COM Common MODBUS RTU. RS485
(Optional)
5 TxD MODBUS A(+)
6 RxD MODBUS A(-)
7 RLY1/NC Normally Closed Programmable Relay 1
(Default A1)
8 RLY1/COM Common
9 RLY1/NO Normally Open
10 RLY2/NC Normally Closed Programmable Relay 2
(Default A2)
11 RLY2/COM Common
12 RLY2/NO Normally Open
13 RLY3/NC Normally Closed Programmable Relay 3
(Default Fault)
14 RLY3/COM Common
15 RLY3/NO Normally Open
16 +VE Sensitive (Sensor Brown Wire)
RFD Sensor Connection17 -VE Non-Sensitive (Sensor Blue Wire)
18 01 Signal (Sensor White Wire)
Table 1: Transmitter terminal connections
Note: The 705 HT sensor (UL Certied only) must be earthed either at the remote junction
box or at the transmitter as appropriate. Avoid earth loops.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
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6.3 Power
The Sensepoint XCD transmitter requires a power supply from the controller of between
16Vdc and 32Vdc. Ensure that a minimum supply of 16Vdc is measured at the sensor,
taking into account the voltage drop due to cable resistance.
The maximum loop resistance in the eld cable is calculated as follows
R loop = (V controller – V detector min) / I detector
Example;
The controller is supplying a nominal 24Vdc (V controller), the detector minimum allowable
voltage is 16Vdc (V detector min), therefore the maximum allowable voltage drop between the
controller and detector is 8Vdc; this means a voltage drop of 4V in each core (+ve core
and -ve core).
Power consumption of the detector is 5.0W. The current required to drive the detector at
the minimum voltage is (I = P / V), 5 / 16 = 312.5 mA (I detector).
So, the maximum eldcable loop resistance (R loop) = 8 / 0.31 = 26 Ohms, or 13 Ohms
per core, (allowing for component variations, losses, etc.).
The following tables show the maximum cable distances between the controller and
transmitter assuming a voltage drop of 3V in each core and for different cable parameters.
The tables are examples only and actual cable parameters and source power supply
voltage for the application should be used to calculate the maximum cable distance
allowed at the installation site.
Typical cable data Maximum Cable length (L)
Cable size
(cross sectional area)
Cable resistance
Ω/km (Ω/mi) Meters Feet
0.5mm2 (20AWG*) 36.8 (59.2) 353 1158
1.0mm2 (17AWG*) 19.5 (31.4) 666 2185
1.5mm2 (16AWG*) 12.7 (20.4) 1023 3356
2.0mm2 (14AWG*) 10.1 (16.3) 1287 4222
2.5mm2 (13AWG*) 8.0 (12.9) 1621 5318
*nearest equivalent
Table 2: Maximum cable distances
+24V
+20V
(wrt Controller 0V)
+4V
(wrt Controller 0V)
0V
4-20mA
Field Cable (L)
Signal
Diagram 7: Power Connection
16V (min) Controller
XCD

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
19
6.4 Cabling
The use of industrial grade, suitably armoured eld cable is recommended.
For example, screened 3 cores (plus screen 90% coverage), suitably mechanically
protected copper cable with a suitable 3/4" explosion-proof gland with 0.5 to 2.5 mm2 (20
to 13 AWG) conductors. Ensure the cable gland is installed correctly and fully tightened.
All unused cable entries must be sealed with a suitable certied sealing plug (one plug is
supplied).
Remote Mounting Cable Details
Type Cable Spec Max Length
RFD Remote AWM2464 AWG20~AWG13 Shield 30meters (98 feet)
6.5 Cable and Earth/Ground regimes
Effective Earth/Ground bonding is important to ensure good EMC and RFI immunity.
The following diagrams show examples of how to earth/ground bond the cable at
enclosures. These bonding techniques provide good RFI/EMC performance. Earth/ground
loops must be avoided to prevent the risk of false signal variation.
Cable to Transmitter
Diagram 8: Controller Grounding
Diagram 9: System grounding
Cable outer sheath Cable inner sheath
Clean / Instrument
Earth Screen
Controller
Power & Signal
Earth Screen
Controller
Transmitter
Note: The Sensepoint HT sensor requires an earth core if the remote junction box does
not have a suitable earth point.

Sensepoint XCD RFD Technical Manual SPXCDHMRFENU Issue 1
20
The Earth Screen of the eld cable should be “tied to Earth” or connected to Ground at
one point only. It is common practise to adopt a STAR EARTH connection regime where
all instrumentation Screens are connected at one common point.
The Screen at the other end of the cable should be “parked” or terminated into a blank
terminal.
The following diagrams show how to install the wire into the ground screw of the
enclosure.
6.6 Ground Terminal Wiring
Internal Ground connection: Utilize the shield of the wiring cable recommended in the
wiring instructions. For connection to this terminal. Twist the shield wire to avoid stray
shield wires, Loosen the screw sufciently and wrap the wire around the screw in a “U”
shape. Raise the clamp and place the wire between the clamp and ground base, lower the
clamp and tighten the screw to 6.9lb-in torque.
External Ground Connection: If required by local authority, Utilize a No 14 AWG copper,
(Stranded or Solid), wire. Loosen the screw sufficiently to enable ‘wrapping the wire
around the screw in a “U” shape. Raise the clamp and place the wire between the clamp
and ground base, lower the clamp and tighten the screw to10.4lb-in torque. A suitable
Ring or Spade type insulated crimp terminal may also be used to accommodate the M4
size external earth screw.
Loosen the bolt Insert cable Fasten the bolt