Detcon FP-100 User Manual

Model FP-100

FP-100 Combustible Gas Sensors

DETCON, INC.

FP-100

LEL

100 %

Operator’s Installation and Instruction Manual

Covers all Model FP-100 Sensors

DETCON, Inc.

3200 Research Forest Dr.,

The Woodlands, Texas 77387

Ph.281.367.4100 / Fax [phone]

www.detcon.com

October 12, 2011 • Document #3736 • Revision 0.0

Model FP-100

This page left intentionally blank

Model FP-100 ii

Model FP-100

Table of Contents

1. Introduction ..................................................................................................................................................1

1.1 Description.......................................................................................................................................... 1

1.2 Modular Mechanical Design............................................................................................................... 2

1.3 Model 100 Standard Terminal Board (Optional)................................................................................ 4

1.4 Model 100 Display Terminal Board (Optional).................................................................................. 4

1.5 Model 100 Series Display (Optional) ................................................................................................. 5

1.6 Wireless Transceiver and Battery Pack (Optional)............................................................................. 5

2. Installation ....................................................................................................................................................6

2.1 Hazardous Locations Installation Guidelines for Safe Use................................................................. 6

2.2 Sensor Placement ................................................................................................................................6

2.3 Sensor Contaminants and Interference ............................................................................................... 7

2.4 Sensor Mounting................................................................................................................................. 8

2.5 Electrical Installation .......................................................................................................................... 9

2.6 Field Wiring...................................................................................................................................... 10

2.6.1 Model 100 Display Terminal Board Settings ............................................................................... 11

2.7 Initial Start Up................................................................................................................................... 11

2.7.1 Toxic Gas Sensors ........................................................................................................................ 11

3. Operation ....................................................................................................................................................13

3.1 Normal Operation ............................................................................................................................. 13

3.2 Calibration ........................................................................................................................................ 14

3.2.1 Zero Calibration............................................................................................................................ 14

3.2.2 Span Calibration ........................................................................................................................... 15

3.3 Fault Diagnostic/Failsafe Feature ..................................................................................................... 17

4. Service and Maintenance............................................................................................................................18

4.1 Replacement of Plug-in Sensor......................................................................................................... 18

4.2 Replacement of ITM......................................................................................................................... 18

4.3 Replacement of the Model 100 Terminal Board............................................................................... 19

5. Troubleshooting Guide...............................................................................................................................21

6. Customer Support and Service Policy ........................................................................................................25

7. FP-100 Sensor Warranty ............................................................................................................................26

8. Specifications .............................................................................................Error! Bookmark not defined.

8.1 Spare Parts, Sensor Accessories, Calibration Equipment ................................................................. 28

8.2 Revision Log..................................................................................................................................... 30

Model FP-100 iii

Model FP-100

Table of Figures

Figure 1 Sensor Assembly with Optional J-Box and LED Display ..................................................................... 1

Figure 2 Sensor Cell Construction ....................................................................................................................... 1

Figure 3 Wheatstone Bridge................................................................................................................................. 2

Figure 4 Response Curves.................................................................................................................................... 2

Figure 5 Sensor Assembly Breakaway................................................................................................................. 3

Figure 6 Functional Block Diagram..................................................................................................................... 3

Figure 7 Plug-in Sensor NEED NEW PICTURE................................................................................................. 3

Figure 8. Standard Terminal Board...................................................................................................................... 4

Figure 9 Model 100 Display Terminal Board ...................................................................................................... 4

Figure 10 Model 100 Series Display.................................................................................................................... 5

Figure 11 Approvals Label................................................................................................................................... 6

Figure 12 Typical FP-100 Sensor Assembly and Mounting Dimensions ............................................................ 9

Figure 13 Typical Installation ............................................................................................................................ 10

Figure 14 Magnetic Programming Tool............................................................................................................. 13

Figure 15 Magnetic Programming Switches ...................................................................................................... 13

List of Tables

Table 1 Wire Gauge vs. Distance ........................................................................Error! Bookmark not defined.

Table 2 Model 100 Terminal Board Jumper ...................................................................................................... 11

Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381

Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067

Phone: [phone] • Fax: [phone] • H

Model FP-100 iv

www.detcon.comH •

Model FP-100

1. Introduction

1.1 Description

Detcon Model FP-100 combustible gas sensors are non-intrusive 4-20mA output sensors designed to detect
and monitor combustible gases in air. Range of detection is 0-100% LEL. The basic sensor assembly consists
of a set of catalytic beads mounted in a stainless steel housing and includes a stainless steel Splash Guard
Adapter. Optionally, the sensor may be installed on an explosion proof junction box and may include a Model
100 Series Display. Other options are available, contact Detcon for more information.

Model 100

DETCON, INC.

FP-100

LEL

100 %

Figure 1 Sensor Assembly with Optional J-Box and LED Display

Catalytic Bead (Pellistor) Sensor Technology

The sensor technology is a poison-resistant catalytic bead type. Catalytic bead sensors show a strong response
to a long list of combustible gases. The sensor is supplied as a matched-pair of detector elements mounted in a
plug-in replaceable module. One bead is a catalytically active detector and the other is a non-active reference
detector. Each detector consists of a fine platinum wire coil embedded in aluminum oxide. A catalytic
mixture is applied to the active detector while the reference detector is treated so that oxidation of the gas does
not occur. The technique is referred to as non-selective and may be used to monitor most any combustible gas.
Detcon catalytic bead sensors are specifically designed to be resistant to poisons such as sulfides, chlorides,
and silicones. The sensors are characteristically stable and capable of providing reliable performance for
periods exceeding 5 years in most industrial environments.

Platinum Wire

Catalyst

Alumina Bead

Construction

of Detector

Bead

Figure 2 Sensor Cell Construction

Catalytic Beads

Main Housing Insert

Printed Circuit Board
Gold Plated Pins

FP-100 Instruction Manual Rev. 0.0 Page 1 of 30

Model FP-100

Principle of Operation

Method of detection is by diffusion/adsorption. Air and combustible gases pass through a sintered stainless
steel filter and contact the heated surface of both the active and reference detectors. The surface of the active
detector promotes oxidation of the combustible gas molecules while the reference detector has been treated not
to support this oxidation. The reference detector serves as a means to maintain zero stability over a wide range
of temperature and humidity.

When combustible gas molecules oxidize on the surface of the active detector, heat is generated, and the
resistance of the detector changes. Electronically, the detectors form part of a balanced bridge circuit. As the
active detector changes in resistance, the bridge circuit unbalances. This change in output is conditioned by
the amplifier circuitry, which is an integral part of the sensor design. The response and clearing characteristics
of the sensor are rapid and provide for the continuous and accurate monitoring of ambient air conditions.

Sensor

Input

Voltage

Cell

Zero

Adjust

Output

Compensator /
Reference Bead

Detector /
Active Bead

Figure 3 Wheatstone Bridge

Performance Characteristics

The detector elements maintain good sensitivity to combustible gas concentrations in the Lower Explosive
Limit (LEL) range, as shown in the response curves in Figure 4. However, for gas concentrations significantly
above the LEL range (100% LEL = 5% by volume Methane), the bridge output begins to decrease.
Ambiguous readings above the LEL range dictate that alarm control logic be of the latching type, wherein
alarms are held in the “ON” position until reset by operations personnel.

Figure 4 Response Curves

1.2 Modular Mechanical Design

The Model FP-100 Sensor Assembly is completely modular and is made up of four parts (See Figure 5 for
Assembly Breakaway):

1) FP-100 Intelligent Transmitter Module (ITM)

2) Intelligent Plug-in Sensor (varies by detector type)

3) 100 Series Bottom Housing Assembly

4) Splash Guard.

FP-100 Instruction Manual Rev. 0.0 Page 2 of 30

circu

Model FP-100

100 Series Bottom

Housing Assembly

Splash Guard

Plug-in
Replaceable
Sensor

3

" NPT Locking Nut

4

FP-100

100 %

LEL

Interconnect

DETCON, INC.

Wires

Intelligent Transmitter Module (ITM)
Micro-processor controlled circuit
encapsulated in an Explosion proof
housing.

O-Ring

Housing Bottom

Locking Screw

Magnetic

Programming

Switches

Figure 5 Sensor Assembly Breakaway

NOTE: All metal components are constructed from electro polished 316 Stainless Steel in

order to maximize corrosion resistance in harsh environments.

FP-100 Intelligent Transmitter Module

The Transmitter Module is a microprocessor-based package that can be attached to an explosion proof junction
box. Circuit functions include bridge drive circuitry, on-board power supply, microprocessor, magnetic
programming switches, and a linear 4-20mA DC output. Magnetic program switches located on either side of
the ITM are activated via a hand-held magnetic programming tool, allowing non-intrusive operator interface
with the Transmitter Module. Electrical classifications are Class I, Division 1, Groups A, B, C, and D.

Plug-In

Sensor

Bridge drive

it

Micro-

Processor

RS-485

4-20mA

Power

I/O

Circuit

Protection

RS-485 Port

Analog 4-20mA Out

Power In

Figure 6 Functional Block Diagram

Field Replaceable Plug-in Sensor

The Detcon family of catalytic bead gas sensors are field proven, plug-in sensors with over-sized gold-plated
connections that eliminate corrosion problems. The sensor can be accessed and replaced in the field easily by
releasing the locking screw and unthreading the Bottom Housing. Detcon’s family of catalytic bead sensors
have a long shelf life and are supported by an industry-leading warranty.

Figure 7 Plug-in Sensor

FP-100 Instruction Manual Rev. 0.0 Page 3 of 30

Model FP-100

1.3 Model 100 Standard Terminal Board (Optional)

If the sensor is ordered with an explosion proof condulet/junction box, the sensor will come with the Model
100 Standard Terminal Board mounted in the J-Box (see Figure 8). This terminal board affords the user easy
plug in connectors for use in wiring the unit during installation, and convenient test points for measuring the
milliamp (mA) output.

Figure 8. Standard Terminal Board

This terminal board provides an easy Digital Volt Meter (DVM) connection for reading the mA output from
the sensor. Two test points (TP1 and TP2) provide a connection across a 10Ω resistor that develops a 10mV
voltage drop per 1mA output. Thus a reading of 40mV on a DVM equals 4mA of current. This is an
alternative method to reading the mA output of the sensor for assemblies that do not include the 100 Series
Display option. Refer to section 2.6 Field Wiring for more information about the setup of the Model 100
Terminal Board.

1.4 Model 100 Display Terminal Board (Optional)

If the unit is ordered with the optional display or a battery pack (as used in wireless configurations) the unit
comes with the Model 100 Display Terminal Board mounted in the J-Box (See Figure 9).

WIRELES

S

N

N

U

K

1

B

B

B

D
N
G

/
W

/
W

L

A

C

D

S

S

DISPLAY

G

/

/

W

W

1
P
S

MODBUS OU

WIRELES

︵

BA

D

V

N

4
2

G

MODBUS IN

D
N
G

AB

PROGRAM

N

I

A

J

8

T

S

︶

V
4
2

SW2

J

1

J

4

SW1

J

5

TER

M

R
W
P

L

9

Figure 9 Model 100 Display Terminal Board

FP-100 Instruction Manual Rev. 0.0 Page 4 of 30

WIRELES

JP1

PROGRAM

J

2

J

7

J

6

POWER I

︵

2
N

I

A

V
4
2

S

SOLAR

A
M

D
N
G

SENSO

D
N
G

AB

N
︶

R
W
P

R

V

/
W

2
P
S

Model FP-100

This terminal board includes connectors for the following:

J1 4-Pin Connector – Modbus Out (Wireless Transceiver Option)
J2 6-Pin Header – Wireless Transceiver Programming Header
J3 8-Pin Beau Connector – used for battery operation or display interface dependant on sensor configuration
J4 4-Pin Connector – Modbus In
J5 6-Pin Connector – used for Display interface with battery/wireless configurations
J6 4-Pin Connector – Sensor connections
J7 4-Pin Connector – Auxiliary power in and mA out.
J8 6-Pin Connector – Wireless Transceiver
J9 5-Pin Header – Terminal Board Programming

The Model 100 Display Terminal Board does not provide test points for measuring the milliamp (mA) output.
The mA output is available at J7.

1.5 Model 100 Series Display (Optional)

The Model 100 Series Display is a 4-digit LED display that provides a direct display of the sensor readings. In
units that are ordered with the optional display, the display is mounted directly onto the J3 Beau connector of
the Display Terminal Board so the display can be easily seen through the J-box window. The display
automatically identifies the ITM, the sensor type, and range. This factory installed option must be ordered
along with the sensor assembly.

Figure 10 Model 100 Series Display

Fault Codes are generated by the 100 series sensors, but these fault codes cannot be visualized unless the
sensor incorporates a display. With the display option, fault codes are displayed as “Fxx” where xx is the
code. Fault Codes are described more in depth in Section 5 Troubleshooting Guide.

1.6 Wireless Transceiver and Battery Pack (Optional)

The FP-100 has the option to operate on a wireless network with the addition of a wireless transceiver and
battery pack. These options allow the sensor to be remotely mounted without the need for external wiring.
These options are factory installed. Contact Detcon for more information on these options.

FP-100 Instruction Manual Rev. 0.0 Page 5 of 30

Model FP-100

2. Installation

2.1 Hazardous Locations Installation Guidelines for Safe Use

1. Install sensor only in areas with classifications matching with those described on the approval label.

Follow all warnings listed on the label.

Figure 11 Approvals Label

2. For Ex d installations, ensure that the sensor is properly threaded into a suitable explosion-proof rated

junction box with a downward pointing female ¾” NPT threaded connection. The sensor should be
threaded up at least 5 full turns until tight, with the LED display facing forward. Avoid use of Teflon
Tape, or any type of non-conductive pipe thread coating on the NPT threaded connection.

3. A good ground connection should be verified between the sensor’s metal enclosure and the junction

box. If a good ground connection is not made, the sensor can be grounded to the junction box using
the sensor’s external ground lug. Also verify a good ground connection between the junction box and
earth ground.

4. Proper precautions should be taken during installation and maintenance to avoid the build-up of static

charge on the plastic components of the sensor. These include the Splash Guard.

5. Do not operate the sensor outside of the stated operating temperature limits.

6. Do not operate the sensor outside the stated operating limits for voltage supply.

7. These sensors meet ATEX standards EN60079-0, EN60079-18 and EN60079-11.

8. These sensors pass dielectric strength of 500VRMS between circuit and enclosure for a minimum of 1

minute at a maximum test current of 5mA.

2.2 Sensor Placement

Selection of sensor location is critical to the overall safe performance of the product. Five factors play an
important role in selection of sensor locations:

(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
(5) Maintenance access

Density

FP-100 Instruction Manual Rev. 0.0 Page 6 of 30

Model FP-100

Placement of sensors relative to the density of the target gas is such that sensors for the detection of heavier
than air gases should be located within 4 feet of grade as these heavy gases will tend to settle in low lying
areas. For gases lighter than air, sensor placement should be 4-8 feet above grade in open areas or in pitched
areas of enclosed spaces.

Leak Sources

The most probable leak sources within an industrial process include flanges, valves, and tubing connections of
the sealed type where seals may either fail or wear. Other leak sources are best determined by facility
engineers with experience in similar processes.

Ventilation

Normal ventilation or prevailing wind conditions can dictate efficient location of gas sensors in a manner
where the migration of gas clouds is quickly detected.

Personnel Exposure

The undetected migration of gas clouds should not be allowed to approach concentrated personnel areas such
as control rooms, maintenance or warehouse buildings. A more general and applicable thought toward
selecting sensor location is combining leak source and perimeter protection in the best possible configuration.

Maintenance Access

Consideration should be given to providing easy access for maintenance personnel. Consideration should also
be given to the consequences of close proximity to contaminants that may foul the sensor prematurely.

NOTE: In all installations the gas sensor should point straight down (refer to Figure 13).
Improper sensor orientation may result in false readings and permanent sensor damage.

Additional Placement Considerations

The sensor should not be positioned where it may be sprayed or coated with surface contaminating substances.
Painting sensor assemblies is prohibited.

Although the sensor is designed to be RFI resistant, it should not be mounted in close proximity to high­powered radio transmitters or similar RFI generating equipment.

When possible mount in an area void of high wind, accumulating dust, rain, or splashing from hose spray,
direct steam releases, and continuous vibration. If the sensor cannot be mounted away from these conditions
then make sure the Detcon Harsh Location Dust Guard accessory is used.

Do not mount in locations where temperatures will exceed the operating temperature limits of the sensor.
Where direct sunlight leads to exceeding the high temperature-operating limit, use a sunshade to help reduce
temperature.

2.3 Sensor Contaminants and Interference

Detcon combustible gas sensors may be adversely affected by exposure to certain airborne substances. Loss of
sensitivity or corrosion may be gradual if such materials are present in sufficient concentrations.

The performance of the detector elements may be temporarily impaired during operation in the presence of
substances described as inhibitors. Inhibitors are usually volatile substances containing halogen compounds.
Inhibitors include halide compounds such as Cl

, ClO2, F2, HF, HCl, Br2, vinyl chloride, and methyl chloride.

2

FP-100 Instruction Manual Rev. 0.0 Page 7 of 30