Det-Tronics R8471E User manual

Instructions 95-8410
Carbon Monoxide Controller
R8471E
2.1 8/07 95-8410

Table of Contents
Section I - General Information
DESCRIPTION................................................................................................1
FEATURES......................................................................................................1
SPECIFICATIONS...........................................................................................2
Controller ..................................................................................................2
Sensor.......................................................................................................2
SYSTEM OPERATION....................................................................................3
Sensor.......................................................................................................3
Controller ..................................................................................................3
Section II - System Installation
INSTALLATION ...............................................................................................9
Sensor Location........................................................................................9
General Wiring Requirements...................................................................9
Sensor Wiring .........................................................................................10
Controller Wiring.....................................................................................11
Controller Programming..........................................................................14
INSTALLATION CHECKLIST........................................................................15
Section III - System Startup
STARTUP PROCEDURE..............................................................................15
SETPOINTADJUSTMENT............................................................................16
Setpoint Display Mode............................................................................16
Setpoint Adjustment Procedure ..............................................................16
CALIBRATION...............................................................................................17
Calibration Procedure.............................................................................17
Current Output Calibration......................................................................18
Section IV - System Maintenance
ROUTINE MAINTENANCE...........................................................................18
Manual Check of Output Devices ...........................................................18
Checkout in Normal Mode ......................................................................18
Hydrophobic Filter...................................................................................18
SENSOR CELL REPLACEMENT..................................................................19
TROUBLESHOOTING ..................................................................................19
REPLACEMENT PARTS...............................................................................19
DEVICE REPAIR AND RETURN...................................................................21
ORDERING INFORMATION.........................................................................21

Section I
General Information
Carbon monoxide (CO) is a colorless, odorless gas
that is toxic to human life at low concentrations.
Figure 1 shows the effects of various concentrations
of CO on the human body.
DESCRIPTION
The R8471E is a single channel, rack mounted
controller that provides continuous monitoring of a
Det-Tronics electrochemical CO sensor or any other
CO sensor/transmitter assembly capable of generating
a 4 to 20 ma dc signal. Controller response includes
actuation of solid state or optional relay outputs for
direct control of field response devices, a full array
of faceplate indicators, as well as an optional 4 to 20
ma output for transmitting system information to other
devices. FEATURES
• Controller accepts a 4 to 20 ma input.
• Digital display, bar graph display and high intensity
LEDs indicate important system status information.
• AutoCal feature provides easy and accurate calibra-
tion.
• Microprocessor based controller is easily field pro-
grammable.
• Three independent alarm outputs with field select-
able setpoints.
• Base model is furnished with solid state alarm and
fault outputs.
• Premium model is furnished with relay outputs and a
4 to 20 ma dc output.
• Current output is selectable for isolated/non-isolated
operation.
• Available operating ranges are 0 to 100, 0 to 500
and 0 to 1000 ppm.
• Rack compatible with Det-Tronics R7400 series
flame controllers.
INSTRUCTIONS
Carbon Monoxide Controller
R8471E
2.1 ©Detector Electronics Corporation 2007 8/07 95-8410
CLEAN AIR
MAXIMUM PERMISSIBLE (8 HR)
HEADACHES
DIZZINESS
UNCONSCIOUSNESS
DEATH
NAUSEA
CEILING LEVEL
1000 PPM
600 PPM
200 PPM
50 PPM
0 PPM A1531
Figure 1—Effects of CO on the Human Body

95-84102.1 2
SPECIFICATIONS
CONTROLLER
OPERATING VOLTAGE—
24 vdc. Can operate in the range of 18 to 32 vdc.
POWER CONSUMPTION (controller only)—
Base model: 0.7 watt nominal, 1.3 watts maxi-
mum (25 ma nominal, 50 ma maxi-
mum at 24 vdc.)
Premium model: 1.2 watts nominal, 3.5 watts maxi-
mum (50 ma nominal, 145 ma
maximum at 24 vdc.)
Maximum startup current is 0.6 ampere for 10 milli-
seconds. Power supplies with fold back current limit-
ing are not recommended.
MAXIMUM RIPPLE—
Not to exceed 5 volts peak-to-peak.
TEMPERATURE RANGE—
Operating: +32°F to +140°F (0°C to +60°C)
Storage: –49°F to +185°F (–45°C to +85°C).
OPERATING RANGES (not programmable)—
0 to 100 ppm, 0 to 500 ppm, or 0 to 1000 ppm.
SOLID STATE OUTPUTS (Base model only)—
The outputs are open collector transistors with a 100K
resistor from the collector to emitter with the emitter
grounded, rated 100 ma at 32 volts dc maximum.
RELAY CONTACTS (Premium model only)—
SPST relays with selectable normally open/normally
closed contacts, rated 5 amperes at 30 vdc.
CURRENT OUTPUT (Premium model only)—
4 to 20 ma, with a maximum external loop resistance
of 600 ohms at 20 vdc and 1100 ohms at 32 vdc.
DIMENSIONS—
See Figure 2.
SHIPPING WEIGHT (approximate)—
2.0 pounds (0.9 kilogram).
SYSTEM APPROVAL—
The R8471E Controller, base and premium model in
3U and 4U height, has been tested and approved by
FMA. It can be used with any FMA approved sens-
ing device capable of generating a 4 to 20 ma input.
FMA approval of the R8471E Controller, however,
does not include or imply approval of input devices
such as sensors or transmitters, or devices connect-
ed to the controller outputs. To maintain FMA system
approval, all equipment connected to the controller
must be FMA approved.
NOTE
Ensure sensor hazardous (classified) location
rating is applicable for the intended use.
SENSOR
OPERATING RANGE (not programmable)—
0 to 100 ppm, 0 to 500 ppm, or 0 to 1000 ppm.
Sensor operating range must match that of controller.
TEMPERATURE RANGE—
+23°F to +105°F (–5°C to +40°C). Recommended
storage: +32°F to +68°F (0°C to +20°C).
TEMPERATURE RESPONSE—
Less than ±10% of gas concentration or ±3% full
scale, whichever is greater, from –5°C to +40°C.
HUMIDITY RANGE—
15 to 90% RH, non-condensing.
PRESSURE RANGE—
Ambient pressure ±10%.
ACCURACY—
±10 percent of applied gas concentration or ±3% full
scale, whichever is greater.
REPEATABILITY—
±2% of applied gas concentration or ±1% full scale,
whichever is greater.
RESPONSE TIME—
20 percent full range within 18 seconds, 50 percent
full range within 30 seconds when CO concentration
equal to full scale is applied.
➛
➛
9.3 (23.6)
1.0
(2.5)
7.0 *
(17.8)
➛
➛
➛
➛
A1526
* 4U DIMENSIONS SHOWN, 3U HEIGHT IS 5.2 (13.3)
Figure 2—Controller Dimensions in Inches (Centimeters)

95-8410
2.1 3
ENCLOSURE MATERIAL—
Aluminum.
DETECTOR RATINGS—
The C7066E is designed to meet FM and CSA require-
ments for Class I, Division 1, Groups C and D.
DIMENSIONS—
See Figures 3 and 4.
SHIPPING WEIGHT (Approximate) —
1.0 pound (0.5 kilogram).
WARRANTY—
Limited warranty 12 months on hardware, 24 months
on sensor cell.
SYSTEM OPERATION
SENSOR
The C7066E CO Sensor consists of an explosion-
proof aluminum housing with a field replaceable
electrochemical sensor cell. The transmitter circuitry
for generating a 4 to 20 ma output signal is contained
within the sensor housing, eliminating the need for a
separate transmitter.
The sensor is designed for use in Class I, Division 1,
Groups C and D hazardous locations.
The C7066E uses a hydrophobic filter to protect the
electrochemical sensor cell from contamination by
dirt and moisture. Unlike metal filters that significantly
restrict the passage of gases to the sensor cell when
the surface is coated with water, the hydrophobic filter
sheds water and will not inhibit the flow of CO gas to
the sensor cell. As with any filter, the hydrophobic
filter must be kept free of contaminants to allow CO
gas to reach the sensor cell.
The hydrophobic filter and electrochemical sensor cell
can be replaced quickly and conveniently in the field.
Sensor Cross Sensitivity
Table 1 shows the response of a typical
electrochemical CO sensor when exposed to various
commonly encountered substances.
CONTROLLER
Faceplate Description
The controller faceplate provides LEDs for identifying
system status conditions, a digital display and a
bar graph display for indicating the sensor input,
and pushbuttons for programming, calibrating and
resetting the system. See Figure 5 for the location of
indicators and pushbuttons.
1. Digital Display - The digital display provides a
continuous reading in parts per million (ppm) of
the sensor input in both the Normal and Calibrate
modes. In the event of a fault, it identifies the
nature of the fault using an alpha-numeric
code. In other operating modes it shows the
alarm setpoints and programmed calibration gas
concentration. A negative zero drift condition is
indicated by a minus (–) sign in the left hand digit.
Since this display is always on, it also functions
as a power indicator (except during the power-
up time delay, when the Fault LED is on and the
digital display is off).
A1527
5.0
(12.7)
3/4 INCH (20 MM)
STANDARD PIPE THREAD
1.1
(2.8)
2.2
(5.6)
3.77
(9.6)
1.28
(3.3)
3.46
(8.8)
4.7
(11.9)
2.7
(6.9)
5.2
(13.2)
5.86
(14.9)
B2281
Figure 4—Junction Box Dimensions in Inches (Centimeters)
Figure 3—C7066E Sensor Dimensions in Inches (Centimeters)
Gas Concentration Signal
Carbon Dioxide 25% 0
Chlorine 10 ppm 0
Ethylene 100 ppm <50
Hydrogen 100 ppm <60 ppm
Hydrogen Chloride 100 ppm 0
Hydrogen Cyanide 100 ppm 0
Hydrogen Sulfide 100 ppm <5 ppm
Methane 5% 0
Nitric Oxide 100 ppm <5 ppm
Nitrogen Dioxide 100 ppm <5 ppm
Sulfur Dioxide 100 ppm <5 ppm
Table 1—Cross Sensitivity of Electrochemical CO Sensor

95-84102.1 4
NOTE
In the event of an over-range condition, the
digital display flashes as long as the over-range
condition exists. The user must exercise caution
if an over-range reading is indicated, since a
dangerous condition could exist. The hazardous
area should be checked with a portable detection
instrument to determine the actual level of CO
gas present.
2. Bar Graph Display - The 20 segment bar graph
display provides a reading of sensor input.
3. High Alarm LED - Flashes in response to a sen-
sor signal that exceeds the high setpoint.
4. Auxiliary Alarm LED - Flashes in response to a
sensor signal that exceeds the auxiliary setpoint.
5. Low Alarm LED - Flashes in response to a sensor
signal that exceeds the low setpoint.
NOTE
Alarm LEDs flash when the setpoint is reached
and are on steady (until reset) when the CO
level drops below the setpoint, whether the
corresponding alarm output is latching or non-
latching.
6. CAL LED - Illuminated while the controller is in the
calibrate mode.
NOTE
In the Setpoint Display or Setpoint Adjust mode,
a flashing alarm LED identifies the particular
setpoint currently being indicated on the digital
display. A flashing CAL LED indicates that the
programmed calibration gas concentration in ppm
is currently being shown on the digital display.
7. FAULT LED - Flashes upon detection of a system
fault and is on steady during the power-up time
delay.
8. RESET Pushbutton - Used for various system
programming and calibration functions as well as
for resetting the controller.
9. SET Pushbutton - Used for various system pro-
gramming and calibration functions.
Operating Ranges
The R8471E is available in three operating ranges:
• 0 to 100 ppm
• 0 to 500 ppm
• 0 to 1000 ppm.
The operating range is not field programmable and
must be specified when ordering.
It is essential for the operating range of the sensor to
match the operating range of the controller to which
it is connected. Note that three sensor housings and
three electrochemical cells are offered. Be sure that
all equipment is compatible when installing the new
system and when replacing sensor cells. Refer to the
“Ordering Information” section.
Setpoints
The R8471E CO Controller has three independent
alarm outputs (low, high and auxiliary), with field
selectable setpoints.
The programmed calibration gas concentration in
ppm is also displayed and adjusted with the alarm
setpoints. This value must be equal to the ppm
concentration of the calibration mixture that is used
for the span adjustment.
Refer to Table 2 for a list of setpoint adjustment
ranges.
Alarm setpoints and calibration gas concentration
can be checked and/or changed using pushbuttons
95-84104
HIGH LED
DIGITAL DISPLAY
BAR GRAPH
CAL LED
FAULT LED
B1384
RESET
PUSHBUTTON
SET
PUSHBUTTON
LOW LED
AUXILIARY LED
Figure 5—Controller Front Panel

95-8410
2.1 5
located on the front panel of the controller. See
the “Set-point Adjustment” section for complete
information.
Outputs
The R8471E Controller is available in a Base version and
a Premium version. The differences between the two
models are the output configuration and programming
options.
BASE MODEL
The base controller is furnished with open collector
transistor outputs (rated 100 ma at 32 volts dc) for
the Low alarm, High alarm, Auxiliary alarm and Fault
circuits. The normally de-energized alarm outputs
are energized when their corresponding setpoints are
reached. The fault output is normally energized and
becomes de-energized upon detection of a system
fault.
The low alarm, auxiliary alarm and fault outputs are non-
latching. The high alarm output is latching.
PREMIUM MODEL
The premium model is furnished with a set of four relays
in place of the four solid state outputs. Relays have
SPST contacts rated 5 amperes at 30 vdc.
This model also includes a selectable isolated/non-
isolated 4 to 20 ma dc current output for transmitting
system information to other devices. The linear 4 to
20 ma output corresponds to CO levels from 0 ppm to
100% full scale (0 to 100, 0 to 500 or 0 to 1000 ppm,
depending on controller model). If a system fault is
detected, the output drops to less than 1.0 ma. The
current output can be calibrated in the field to ensure
maximum accuracy. Refer to the “Calibration” section.
PROGRAMMING OPTIONS (PREMIUM MODEL ONLY)
Each of the four relays is field selectable for either
normally open or normally closed contacts using jumper
plugs located on the printed circuit board inside the
controller. (See Table 3.)
The alarm relays are also switch programmable for either
normally energized or normally de-energized operation
(programmable as a group only, not individually). The
fault relay is normally energized.
The low and auxiliary alarm relays are programmable
for either latching or non-latching operation. The high
alarm relay is always latching and the Fault relay is
non-latching. Latching relays are reset using either the
Reset pushbutton on the front panel of the controller or
an external reset switch.
The 4 to 20 ma circuit is selectable for isolated or non-
isolated operation.
Automatic Diagnostics and Fault Identification
The microprocessor based controller features self-
testing circuitry that continuously checks for problems
that could prevent proper system response. When
power is applied, the microprocessor automatically tests
memory. In the Normal operating mode, it continuously
monitors the input signal from the sensor to ensure
proper functioning. In addition, a “watchdog” timer
is maintained to ensure that the program is running
correctly. If a fault should occur:
— The FAULT LED flashes.
— The digital display identifies the nature of the fault
using an alpha-numeric code. Refer to Table 4 for
an interpretation of the codes.
95-84105
Range Low Alarm High Alarm Auxiliary Alarm Calibration Gas
0 to 100 5 to 50 10 to 90 5 to 90 30 to 90
Default 10 20 20 50
0 to 500 25 to 250 50 to 450 25 to 450 150 to 450
Default 50 100 100 250
0 to 1000 50 to 500 100 to 900 50 to 900 300 to 900
Default 100 200 200 500
Table 3—Selectable Relay Options
Relay Selectable Selectable Selectable
Normally Normally Latch/
Open/Closed Energized/ Non-Latch
De-Energized
Low Y Y1Y
1
High Y Y1N
2
Auxiliary Y Y1Y
1
Fault Y N3N
4
Y = Yes N = No
1Selectable as a group, not individually 2Latching only
3Normally energized only 4No latching option
Table 2—Setpoint Adjustment Ranges in PPM

95-84102.1 6
— The normally energized Fault output is de-ener-
gized.
— The dc current output drops to less than 1.0 ma.
NOTE
The fault code will be shown for about 2 seconds
out of every 5 seconds. The gas concentration at
the sensor will be displayed during the remaining
time. If more than one fault should occur, the
highest priority fault will be displayed. (Table 4
lists the faults in order of priority.)
An alarm condition will normally over-ride a fault
condition unless the fault condition occurred first. F10
and F2X will not over-ride an alarm. Faults that affect
the actual function of the controller (F50, F60, F70, F9X)
can impair the ability of the controller to maintain an
alarm output.
All faults automatically reset except the F9X, F20 and
F10 faults. After the fault condition has been corrected,
the fault output automatically switches to the normal
(energized) state, the dc current output returns to
normal, and the FAULT LED turns off. Clearing F9X
faults requires removing operating power from the
controller for approximately one second.
CAUTION
The fault detection circuitry does not monitor the
operation of external response equipment or the
wiring to these devices. It is important that these
devices be checked periodically to ensure that
they are operational.
Operating Modes
NOTE
The following section is intended to acquaint the
operator with the basic operation of the controller.
For complete step-by-step programming and
calibration procedures, refer to corresponding
sections in this manual.
The controller can operate in any of the following modes.
Operating modes other than Normal are selected by
pressing the appropriate pushbutton(s) located on the
controller front panel. See Figure 6.
POWER-UP TIME DELAY
When power is applied to the controller, it enters a
time delay mode to allow the sensor output to stabilize
before beginning normal operation. During this time
the outputs are inhibited, the FAULT LED is illuminated
and the current output indicates a fault condition (less
than 1.0 ma). At the end of the time delay, the controller
automatically enters the Normal operating mode.
NORMAL
In Normal operating mode with no alarm condition:
— Digital display is on and indicates the sensor input
in ppm.
95-84106
Table 4—System Status Codes
Status Condition
F9X Initialization failure. (Subcodes are as fol-
lows.)
F91 EPROM sumcheck failure.
F92 Sensor failure during startup - current too
high or too low.
F93 Watchdog timer failure.
F94 RAM failure.
F95 Internal 5 volt power supply failure during
startup.
F96 External 24 volt power supply failure dur-
ing startup.
F97 Controller type invalid. Error in data from
RAM.
F98 Watchdog timer reset the controller.
F70 External reset button has been activated
for 15 seconds or longer. Self clearing
when button is released.
F60 External 24 vdc power input is not in the
18 to 32 vdc range.
F50 Internal 5 volt power supply is not in the
4.75 to 5.25 volt range.
F40 Sensor fault (after startup). Input is above
35 ma or below 2 ma.
F30 Negative zero drift. Sensor input is –9%
full scale or lower.
F2X Calibration error. (Subcodes are as fol-
lows.)
F20 General calibration fault, or calibration
aborted due to a higher priority fault.
F21 Time ran out while waiting for calibration
gas to be applied to the sensor.
F22 Sensor input is too low. The sensor cannot
generate enough offset to get an accurate
calibration. Replace sensor.
F23 Sensor is too sensitive for the controller to
read 100% full scale. Replace sensor.
F24 Zero gas level too high, or sensor zero
input over limit.
F10 Sensor reaching end of life. Consider
replacing the sensor within the next two
calibration periods.

95-8410
2.1 7
— Bar graph display reads the same as the digital
display.
— All LEDs are off.
— Alarm outputs are in their normal state (energized
or de-energized as programmed).
— 4 to 20 ma signal level corresponds to sensor
input.
— Fault output is energized.
In the Normal operating mode with a low and/or auxil-
iary alarm condition occurring:
— Digital display and bar graph display indicate the
sensor input in ppm.
— Low and/or Auxiliary LED flashes.
— Low and/or Auxiliary alarm output changes state.
— 4 to 20 ma signal level corresponds to sensor
input.
— Fault output energized and LED off.
When the signal decreases below the low or auxiliary
setpoint:
— Digital display, bar graph display and 4 to 20 ma
output continue to track the sensor input.
— With latching operation programmed: No change
to alarm outputs.
— With non-latching operation programmed: Alarm
outputs return to their normal state.
— Low and Auxiliary LEDs are on steady until reset.
In the Normal operating mode and a high alarm con-
dition occurring:
— Same as a low or auxiliary alarm condition, but
High LED and high alarm output are affected.
When the signal decreases below the high alarm set-
point:
— The high alarm is always latching and unaffected
by the latching/non-latching programming for the
low and auxiliary alarms. High LED is on steady
until reset.
In the event of a system fault:
— The normally energized Fault output is de-ener-
gized and the FAULT LED is illuminated.
— 4 to 20 ma output drops to less than 1.0 ma.
RESET
The Reset mode is entered by pressing the RESET
button located on the front panel of the controller.
(See Figure 6.) When the RESET button is momen-
tarily depressed, all LEDs turn off and all outputs
return to their normal condition if no alarms or faults
are occurring (basic reset). When the RESET button
is held for 0.5 second, the LEDs turn off and the out-
puts return to their normal condition even if an alarm
or fault condition still exists (forced reset). Remote
95-84107
POWER-UP
POWER-UP
DELAY
NORMAL RESET
< 0.5 SEC. 1.0 SEC.
HOLD RESET
7 SEC.
SET
1.0 SEC. NO
YES
0.5 SEC 9.0 SEC.
BASIC
RESET FORCED RESET
RELEASE
RESET
RELEASE
RESET
RELEASE
RESET
SETPOINT
DISPLAY
HOLD
RESET
HOLD
RESET
HOLD
RESET
SENSOR
REPLACE
SETPOINT
ADJUST
CURRENT
CALIBRATE
RESET
PUSHED WITH
SET?
CALIBRATE
SET*
RESET
*MUST BE PRESSED BEFORE THE ZERO
CALCULATIONS ARE COMPLETED.
C1385
Figure 6—R8471E Controller Flow Chart

95-84102.1 8
reset capability is also provided. (Remote reset per-
forms a forced reset.)
NOTE
The remote reset performs a reset function only.
It cannot be used for entering other controller
operating modes.
SETPOINT DISPLAY MODE
If the RESET button is held for approximately one
second, the controller enters the Setpoint Display
mode. In this mode, the digital display sequentially
shows the programmed alarm setpoints and
calibration gas concentration. Each value is displayed
for approximately 2 seconds. After completing the
sequence, the controller automatically returns to the
Normal operating mode if the RESET button is no longer
being depressed.
This mode is used only for displaying the setpoints. Use
the “Setpoint Adjust” mode for changing setpoint and
calibration gas values.
CALIBRATE
The R8471E uses a fully automatic calibration procedure
that requires no adjustments by the operator. The
Calibrate mode is entered by pressing and holding the
RESET button until completion of the “Setpoint Display”
sequence described above (approximately 9 seconds).
The controller performs the Zero adjustments, then
signals the operator when to apply and also when
to remove the calibration gas. Upon completion of
a successful calibration, the controller automatically
returns to the Normal operating mode.
If the operator fails to complete the calibration
procedure, if an error in calibrating occurs, or if a
successful calibration cannot be completed, the
microprocessor will automatically return to the Normal
mode and continue to use the previous calibration data
(after 10 minutes or when the gas level drops below the
lowest setpoint). A fault indication (“F2X” status) will be
displayed until a reset occurs. If the microprocessor
determines that the sensor cell is approaching the end
of its useful life, “F10” will be indicated on the digital
display.
See “Calibration” section for complete information.
While in the Calibrate mode, all controller outputs are
inhibited, the CAL LED is illuminated and the dc current
output goes to a preset level (adjustable from 0 to 20
ma, with a default value of 4.0 ma).
SENSOR REPLACEMENT
This mode inhibits all controller outputs to allow
replacement of the sensor cell without removing power
from the controller. In addition, this mode automatically
sets the factory default values for sensor calibration.
Alarm setpoints and calibration gas concentration are
not affected.
CAUTION
Upon entering the Sensor Replacement mode, all
previously entered sensor calibration information
is lost. Sensor calibration must be performed,
even if the sensor cell was not replaced.
To enter the Sensor Replacement mode, either enter the
Calibrate mode as described above and press the SET
button, or hold the RESET button for 7 seconds while in
the power-up time delay. To exit this mode, press the
RESET button. Upon exiting the Sensor Replacement
mode, the controller automatically returns to normal
operation.
SETPOINTADJUST
The Setpoint Adjust mode is entered by depressing
the SET button for approximately one second. In this
mode the alarm setpoints and calibration gas level
are sequentially displayed on the digital display for
approximately five seconds and the corresponding LED
flashes. To change the setpoint, depress the RESET
button to increase the displayed value or the SET button
to decrease the value. If no changes are made for 5
seconds, the microprocessor automatically advances
to the next setpoint. At the end of the sequence, the
microprocessor automatically returns to the Normal
operating mode.
DC CURRENT OUTPUT CALIBRATION
This mode is used to calibrate the 4 to 20 ma dc
output. To enter this mode, hold the SET button, then
press RESET. Initially, a 4 ma output is generated
for approximately 7 seconds while the Low LED
flashes. Then 20 ma is generated while the High
LED flashes. Finally the current output level during
calibration is generated while the CAL LED flashes.
The microprocessor automatically returns to the
normal operating mode at the end of the sequence.
Adjustments to the current output level are made by
pressing the RESET (increase) or SET (decrease)
button. This procedure requires a dc current meter to
monitor the actual controller dc milliampere output.
95-84108

95-8410
2.1 9
Section II
System Installation
INSTALLATION
SENSOR LOCATION
Proper location of the sensor is essential for providing
maximum protection. The formula for determining
the most effective number and placement of sensors
varies depending on the conditions at the job site.
The individual performing the installation must rely on
experience and common sense to determine the number
of sensors needed and the best sensor locations to
adequately protect the area.
The following factors are important and should be
considered for every installation:
1. Select a location for the sensor as close as practi-
cal to an anticipated source of CO gas.
2. Ventilation characteristics of the immediate area
must also be considered. Air movement will
cause the gas to accumulate more heavily in one
area than another. Sensors should be placed
where the most concentrated accumulation of
carbon monoxide gas is anticipated. Also con-
sider the fact that some ventilation systems do not
operate continuously.
3. The sensor should be located where it is safe from
potential sources of contamination.
4. The sensor should be pointed down to prevent
the buildup of contaminants on the filter.
5. The sensor must be accessible for testing and
calibration.
6. Exposure to excessive heat or vibration can
cause premature failure of electronic devices,
and should be avoided if possible. Shielding
the device from intense sunlight will reduce solar
heating and can increase the life of the unit.
GENERAL WIRING REQULREMENTS
NOTE
The wiring procedures in this manual are intended
to ensure proper functioning of the device under
normal conditions. However, because of the
many variations in wiring codes and regulations,
total compliance to these ordinances cannot be
guaranteed. Be certain that all wiring complies
with applicable regulations that relate to the
installation of electrical equipment in a hazardous
area. If in doubt, consult a qualified official
before wiring the system.
The use of shielded cable is highly recommended
for wiring the CO detection system to protect against
interference caused by extraneous electrical “noise.”
In applications where the wiring cable is installed in
conduit, the conduit must not be used for wiring to
other electrical equipment.
Since moisture can be detrimental to electronic devices,
it is important that moisture not be allowed to come in
contact with the electrical connections of the system.
Moisture in the air can become trapped within sections
of conduit. Therefore, the use of conduit seals is
required to prevent damage to electrical connections
caused by condensation within the conduit.
These seals must be watertight and explosion-proof
and are to be installed even if they are not required by
local wiring codes. A seal must be located as close
to the junction box as possible. In no case should this
seal be located more than 18 inches (46 cm) from the
junction box. When an explosion-proof installation is
required, an additional seal may be needed at any point
where the conduit enters a non-hazardous area. Always
observe the requirements of local codes.
When pouring a seal, the use of a fiber dam is required
to assure proper formation of the seal. The seals should
never be poured in temperatures that are below freezing,
since the water in the sealing compound will freeze and
the compound will not dry properly. Contamination
problems can then result when temperatures rise above
the freezing point and the compound thaws.
The shielding of the cable should be stripped back
to permit the seal to form around the individual leads,
rather than around the outside of the shield. This will
prevent any siphoning action through the inside of the
shield. The shield should not be cut.
Conduit breathers are also recommended. In some
applications, alternate changes in temperature and
barometric pressure can cause “breathing,” which
allows the entry and circulation of moist air throughout
the conduit. Joints in the conduit system and its
components are seldom tight enough to prevent this
“breathing.” Moisture in the air can condense at the
base of vertical conduit runs and equipment enclosures,
and can build up over a period of time. This can be
detrimental to electronic devices. To eliminate this
condition, explosion-proof drains and breathers should
be installed to automatically bleed off accumulated
water.
95-84109

95-84102.1 10
SENSOR WIRING
The maximum distance between the sensor and con-
troller is limited by the resistance of the connecting
wiring, which is a function of the gauge of the wire
being used. Table 5 shows the maximum wiring dis-
tance allowed for a given wire size.
1. Determine the best mounting locations for the
sensors. Whenever practical, sensors should be
placed where they are easily accessible for cali-
bration.
2. The sensor junction box can be mounted to a wall
or post, or it can be suspended by the conduit.
The junction boxes should be electrically con-
nected to earth ground.
The sensor must be oriented with the filter point-
ing down. Position the junction box with the con-
duit connected to the upper opening. The sensor
will be installed in the lower opening on the junc-
tion box.
3. Remove the cover from the junction box.
NOTE
Do not apply power to the system with the
junction box cover removed unless the area has
been de-classified.
4. Remove the cap from the sensor base. See
Figure 7.
5. Remove the sensor cell from its packaging.
Determine proper orientation, then carefully plug
it into the sensor base.
NOTE
Handle the sensor cell carefully. To avoid
possible damage, observe the normally accepted
procedures for handling electrostatic sensitive
devices. See form 75-1005 for more information.
6. Be sure that the O-ring is in good condition, then
place the cap back on the sensor base. Tighten
only until snug. Do not over tighten.
7. Attach the sensor to the junction box. The sen-
sor should be tight to ensure an explosion-proof
installation, however, do not over tighten.
NOTE
Coat the sensor threads with an appropriate
grease to ease installation. Also lubricate the
junction box cover threads. The recommended
lubricant is a silicone free polyalphaolefin grease
available from Det-Tronics.
8. Connect the sensor wires to the sensor terminal
block inside the junction box. (See Figure 8.)
Connect the controller wiring to the controller ter-
minal block inside the junction box.
Connect the shield to earth ground at the
controller end only. Under normal conditions, the other
B1203
SENSOR BASE
SENSOR CELL
CAP
HYDROPHOBIC FILTER
NOTE: SENSOR APPEARANCE MAY VARY
SLIGHTLY DEPENDING UPON MODEL.
Figure 7—Exploded View of Sensor
Table 5—Maximum Wiring Distances – Controller to Sensor
Maximum Sensor
Wire Size to Controller
(AWG) Distance
Feet Meters
18 5700 1750
16 9000 2800

95-8410
2.1 11
end of the shield should not be connected at the sensor
junction box, unless such a connection is required by
local wiring codes. The wiring code is:
Red lead = “+/power”
Black lead = “–/signal”
Green lead = Chassis (earth) ground
9. Check the sensor wiring to ensure proper connec-
tions, then pour the conduit seals and allow them
to dry (if conduit is being used).
10. Place the cover back on the junction box.
CONTROLLER WIRING
NOTE
The controller contains semiconductor devices
that are susceptible to damage by electrostatic
discharge. An electrostatic charge can build
up on the skin and discharge when an object
is touched. Therefore, use caution when
handling, taking care not to touch the terminals
or electronic components. For more information
on proper handling, refer to Service Memo 75-
1005.
Field Wiring Connector
The controller is furnished with a field wiring connec-
tor backplate that incorporates pressure type screw
terminals for connecting the external wiring and a
circuit board edge connector for attaching to the con-
troller.
The use of a mounting rack is required for mounting
the controller. The backplate is attached to the back
of the rack to allow easy removal of the controller with-
out disturbing the wiring. See Figures 9 and 10.
The controller is designed for installation in a non-haz-
ardous area.
Figure 11 shows the terminal configuration for the
R8471E CO Controller.
Terminals 1 and 2 – 4 to 20 ma dc output.
Non-Isolated Current Output -
If the 4 to 20 ma current loop
is to be non-isolated, wire the
current loop as shown in Figure
12. Note that terminal 2 is not
used with a non-isolated current
loop. Program the controller
for a non-isolated current loop
as described in the “Controller
Programming” section.
Isolated Current Output - If an
isolated current loop is desired,
wire the current loop as shown
in Figure 13 and program the
controller for an isolated cur-
rent loop as described in the
“Controller Programming” sec-
tion of this manual. Note that
this wiring scheme requires an
external power source for the
isolated current output.
Terminal 3 – Connect to chassis (earth)
ground. Ground the cable
shield at this terminal.
Terminal 4 – Connect to the positive (+)
side of the 18 to 32 vdc power
source.
Terminal 5 – Connect to the negative (–) side
of the dc power source.
NOTE
If local wiring codes permit and if a ground fault
monitoring system is not being used, the minus
side of the dc power source can be connected
to chassis (earth) ground. Alternatively, a 0.47
microfarad, 100 volt capacitor can be installed
(terminal 5 to ground) for best immunity against
electromagnetic interference.
SENSOR
CONDUIT SEAL
FIBER DAM
GROUND
BLK (–) TO SIGNAL
RED (+) TO POWER
WIRING TO CONTROLLER
GROUND JUNCTION BOX
ACCORDING TO LOCAL CODES
A1528
RED
BLK
GRN
=
=
=
+
–
GROUND
Figure 8—Sensor Wiring

95-84102.1 12
Figure 10—Clip Positioning for Mounting Racks
Figure 9—Dimensions of Mounting Rack
(A)
(B)
(C)
1.48 (37.59)
(D)
A1475 ALL CONTROLLER CAGES REQUIRE A MINIMUM OF 10.12 INCHES (257.1 MM) DEPTH CLEARANCE
(E)
1
A1476
FIRE CONTROLLERS ARE APPROX. TWO INCHES
WIDE AND REQUIRE TWO GUIDE RAILS FOR
INSERTION. PLACE THE RETAINING CLIP BETWEEN
RAILS TO FORM SETS, LEAVE A GAP BETWEEN SETS.
SET SETGAP
123 2
THE Q4004 CONTROLLER CAGE HAS BEEN MODIFIED
TO ACCOMMODATE EITHER FIRE OR GAS CONTROLLERS
OR ANY COMBINATION OF THE TWO.
BY FOLLOWING THE INSTRUCTIONS BELOW, THE CAGE
CAN BE SET UP TO ANY CONFIGURATION.
2TO INSERT A BLANK PANEL, PLACE A CLIP IN
THE TOP BRACKET IN LINE WITH THE CLIP IN THE
BOTTOM BRACKET.
3
GAS CONTROLLERS ARE APPROX. ONE INCH WIDE
AND REQUIRE ONE RAIL FOR INSERTION. PLACE CLIPS
IN LINE WITH GUIDE RAILS, CAGES WILL ACCEPT AS
MANY GAS CONTROLLERS AS RAILS PROVIDED.
CONTROLLER
POSITIONS FOR: HT: DIM. (A) DIM. (B) DIM. (C) DIM. (D) DIM. (E)
FIRE GAS INCH MM INCH MM INCH MM INCH MM INCH MM
8 16 4U 19.00 482.6 18.30 464.8 17.36 440.9 4.00 101.6 6.97 177.1
6 12 4U 15.06 382.6 14.36 364.7 13.42 340.9
4 8 4U 11.13 282.6 10.43 264.9 9.49 241.1
3 6 4U 9.16 232.7 8.46 214.9 7.52 191.0
2 4 4U 7.19 182.7 6.49 164.9 5.55 141.0
1 2 4U 5.22 132.6 4.52 114.8 3.58 90.9
16 3U 19.00 482.6 18.30 464.8 17.36 440.9 2.25 57.15 5.22 132.6
12 3U 15.06 382.6 14.36 364.7 13.42 340.9
8 3U 11.13 282.6 10.43 264.9 9.49 241.1
6 3U 9.16 232.7 8.46 214.9 7.52 191.0
4 3U 7.19 182.7 6.49 164.9 5.55 141.0
2 3U 5.22 132.6 4.52 114.8 3.58 90.9

95-8410
2.1 13
Terminal 6 – Connect to the red (+) lead of
the C7066E Sensor.
Terminal 7 – Connect to the black (–) lead of
the C7066E Sensor.
Terminal 8 – A normally open momentary clo-
sure switch can be connected
between this terminal and the
negative (–) side of the power
source for remote reset.
Terminals 9 and 10 – High Alarm Output.
Terminals 11 and 12 – Auxiliary Alarm Output.
Terminals 13 and 14 – Low Alarm Output.
Terminals 15 and 16 – Fault Output.
BASE CONTROLLER
Connections to open collector transistor outputs are
made at terminals 10, 12, 14 and 16. Terminals 9, 11,
13 and 15 are not used. See Figure 14 for an example
of a typical connection to an open collector transistor
output.
NOTE
External equipment that can generate transients
when switching (such as relays) must have
a transient suppression device (diode)
connected across the coil at the time of
installation. (Note proper polarity of the diode.)
This will safeguard the output transistors of the
controller against possible damage. Figure 14
illustrates an inductive load with a diode used for
transient suppression.
Figure 12—ATypical System – R8471E with Relay Outputs,
Non-Isolated Current Output and C7066E Sensor
CURRENT OUTPUT
CHASSIS GROUND
POWER
SENSOR
EXTERNAL RESET
HIGH ALARM
HIGH ALARM / OC
AUX. ALARM
AUX. ALARM / OC
LOW ALARM
LOW ALARM / OC
FAULT
FAULT / OC
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
–
+
+
–
+
–
18 TO 32
VDC
POWER
SIGNAL
2
OC = OPEN COLLECTOR OUTPUT
(BASE MODEL ONLY) B1390
Figure 11—Terminal Configuration for R8471E CO Controller
CURRENT OUTPUT
CHASSIS GROUND
POWER
SENSOR
EXTERNAL RESET
HIGH ALARM
HIGH ALARM / OC
AUX. ALARM
AUX. ALARM / OC
LOW ALARM
LOW ALARM / OC
FAULT
FAULT / OC
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
–
+
+
–
+
–
18 TO 32
VDC
POWER
SIGNAL
HIGH
ALARM
AUXILIARY
ALARM
LOW
ALARM
FAULT
RESET
24
VDC
+
–
C7066E
2
A1529
R8471E CONTROLLER
4 TO 20 MA
BLK
RED
GREEN
+–
OC = OPEN COLLECTOR OUTPUT
(BASE MODEL ONLY)
CURRENT OUTPUT
CHASSIS GROUND
POWER
SENSOR
EXTERNAL RESET
HIGH ALARM
HIGH ALARM / OC
AUX. ALARM
AUX. ALARM / OC
LOW ALARM
LOW ALARM / OC
FAULT
FAULT / OC
1
3
4
5
6
7
8
9
10
11
12
13
14
15
16
–
+
+
–
+
–
18 TO 32
VDC
POWER
SIGNAL
HIGH
ALARM
AUXILIARY
ALARM
LOW
ALARM
FAULT
RESET
24
VDC
+
–
C7066E
SENSOR
2
A1530
R8471E CONTROLLER 4 TO 20 MA
BLK
RED
GREEN
+–24
VDC
+
–
OC = OPEN COLLECTOR OUTPUT
(BASE MODEL ONLY)
Figure 13—ATypical System - R8471E with Isolated Current Output

95-84102.1 14
PREMIUM CONTROLLER
The relay outputs (terminals 9 to 16) are programmed
for the desired operation using the procedure described
in the “Controller Programming” section.
CONTROLLER PROGRAMMING
Refer to Figure 15 to determine the location of
programming jumpers and switches. Table 3 shows the
selectable options for each relay.
IMPORTANT
All jumper plugs must be installed. The
controller outputs will not function properly if a
jumper plug is missing.
Normally Open/Closed Relays
The four relays are individually programmed for either
normally open or normally closed contacts. This is
accomplished by placing a jumper plug on the
appropriate pair of pins. Each relay has a set of three
pins. For normally open operation, place the plug on
the NO and center pins. For normally closed operation,
place it on the NC and center pins. The pin groups are
identified as follows:
J2 – High Alarm
J3 – Auxiliary Alarm
J4 – Low Alarm
J5 – Fault
The controller is programmed at the factory for nor-
mally open relay contacts.
100K
OPEN COLLECTOR OUTPUT
1N4004
TYPICAL
+32 VDC MAXIMUM
B1289
Figure 14—Open Collector Output with Inductive Load
and Transient Suppression Device
Figure 15—Programming Jumper Plugs and Switches
A1392
HIGH ALARM
SW1-1 CLOSED = LATCHING
OPEN = NON-LATCHING
SW1-2 CLOSED = NORMALLY ENERGIZED
OPEN = NORMALLY DE-ENERGIZED
LOW ALARM
FAULT
AUXILLIARY ALARM
NORMALLY
OPEN/CLOSED
RELAY CONTACTS
J1 INT = NON-ISOLATED
EXT = ISOLATED

95-8410
2.1 15
Latching/Non-Latching Relays
The Low and Auxiliary alarm relays are programmable
for latching or non-latching operation. The High alarm
relay is always latching. Latching relay operation is
programmed using rocker switch 1 at SW1 (SW1-1).
For latching operation, place the switch in the closed
position. For non-latching operation, place it in the
open position. This switch is set at the factory for non-
latching relay operation.
Normally Energized/De-Energized Relays
The three alarm relays are programmable for normally
energized (fail-safe) or normally de-energized operation.
This is accomplished by setting rocker switch 2 at SW1
(SW1-2). For normally energized alarm relays, place the
switch in the closed position. For normally de-energized
operation, place it in the open position. This switch is
set at the factory for normally de-energized operation.
The Fault relay is always normally energized, regardless
of the setting of SW1-2.
NOTE
If the switch positions of SW1 are changed while
power is applied, power must be cycled for the
change to take effect.
4 to 20 ma Output
Isolated or non-isolated operation of the 4 to 20 ma
output is selected using a jumper plug at J1. For non-
isolated operation, as illustrated in Figure 12, place the
jumper plug in the INT (internal power source) position.
Place the plug in the EXT position for an isolated circuit
(external power source), as illustrated in Figure 13. The
jumper is set at the factory for non-isolated operation.
INSTALLATION CHECKLIST
The following checklist is provided as a means of double
checking the system to be sure that all phases of system
installation are complete and have been performed
correctly.
1. Junction boxes are mounted securely and sen-
sors are pointing down.
2. All cable shields are properly grounded.
3. All junction box covers are tightly installed.
4. Explosion-proof conduit seals have been installed
at all junction box entries (if conduit is being
used).
5. Sensor to controller wiring is correct.
6. Power wiring to the controller is installed and
power source is operational.
7. External loads are properly connected to the con-
troller.
8. Controller is programmed as desired. Record this
information for future reference.
9. Controller is properly installed in the mounting
rack.
10. Proper ventilation is provided to prevent over-
heating of the controller.
Proceed to System Startup, Setpoint Adjustment and
Calibration.
Section III
System Startup
STARTUP PROCEDURE
1. Output loads that are controlled by the system
should be secured (remove power from all output
devices) to prevent actuation.
2. Check all external wiring for proper connection.
Be sure that the sensor has been wired properly.
3. Before installing the controller in the mounting
rack, inspect it to verify that it has not been physi-
cally damaged in shipment. Check the jumper
plugs and rocker switches on the controller for
proper programming, then slide the controller fully
into the mounting rack.
4. Apply power to the system.
NOTE
When power is applied to the system, the
controller enters a time delay mode before
beginning normal operation. During this time
the outputs are inhibited, the FAULT LED is
illuminated and the current output indicates a
fault condition. This delay allows time for the
sensor output to stabilize before normal operation
is begun. The controller automatically exits the
time delay mode after 5 minutes have elapsed or
as soon as the sensor output no longer exceeds
any alarm setpoints.

95-84102.1 16
5. Put the controller in the Setpoint Display mode
to determine the present alarm setpoints and
calibration gas concentration. If changes are
required, perform the Setpoint Adjustment proce-
dure.
6. Perform the calibration procedure.
7. Check the 4 to 20 ma current loop for proper cali-
bration and adjust as required.
8. Remove mechanical blocking devices (if used)
and restore power to the output loads.
SETPOINT ADJUSTMENT
Refer to Table 2 to determine the adjustment ranges for
the alarm setpoints and calibration gas concentration for
the controller model being used.
To check the present levels, use the “Setpoint Display
Mode” described below. To change the values, use the
“Setpoint Adjustment Procedure.”
SETPOINT DISPLAY MODE
1. To enter the Setpoint Display mode, press and
hold the RESET button until the Low LED begins
to blink (approximately one second). Release
the RESET button. The low alarm setpoint will be
shown for two seconds on the digital display.
NOTE
The RESET button should be released as
soon as the controller has entered the Setpoint
Display mode (after one second). If the button
is still depressed at the end of the Setpoint
Display mode (9 seconds), the controller will
automatically enter the Calibrate mode. If the
operator is not prepared to perform a calibration,
a calibration fault will occur. Recycle power to
the controller to exit the calibrate mode without
affecting the calibration settings.
2. At the end of the two second interval, the Low
LED goes out, the High LED blinks and the digital
display shows the high alarm setpoint.
3. Two seconds later the High LED goes out and
the Auxiliary LED blinks. The digital display now
shows the auxiliary alarm setpoint.
4. Two seconds later the Auxiliary LED goes out
and the CAL LED blinks. The digital display now
shows the programmed calibration gas concen-
tration.
5. After displaying the calibration gas concentra-
tion for two seconds, the controller automatically
leaves the Setpoint Display mode and returns to
the Normal operating mode.
6. If adjustments to the setpoints are required, per-
form the “Setpoint Adjustment Procedure.” When
the setpoint levels are acceptable, record this
information for future reference and perform the
“Calibration Procedure.”
SETPOINT ADJUSTMENT PROCEDURE
1. Determine the required alarm setpoint levels and
calibration gas concentration.
2. Press and hold the SET button for one second,
then release. The digital display indicates the
present low alarm setpoint and the Low LED
blinks. Press the RESET button to increase the
reading or the SET button to decrease the read-
ing. (Holding the button will cause the reading to
change rapidly.)
3. When no changes to the setpoint level have been
made for 5 seconds, the Low LED goes out, the
High LED blinks and the digital display shows the
high alarm setpoint. Press the appropriate button
(detailed in step 2 above) to obtain the desired
reading on the digital display.
4. When no changes to the setpoint level have been
made for 5 seconds, the High LED goes out, the
Auxiliary LED blinks and the digital display shows
the auxiliary alarm setpoint. Press the appropriate
button to obtain the desired reading on the digital
display.
5. When no changes have been made for 5 sec-
onds, the Auxiliary LED goes out, the CAL LED
blinks and the digital display indicates the cali-
bration gas concentration. Press the appropriate
button to change the value to match the actual
gas concentration used for sensor calibration.
6. When no changes have been made for 5 sec-
onds, the controller automatically returns to the
Normal operating mode.
7. Record the new values for future reference.
NOTE
The alarm setpoints, calibration gas concentration
and calibration data are stored in non-volatile
memory and are retained in the event of a
power loss. However, if power is interrupted
while performing the “Setpoint Adjustment” or

95-8410
2.1 17
“Calibration Procedure,” the entire procedure
must be repeated when power is restored.
CALIBRATION
To ensure optimum protection, the CO detection
system must be calibrated on a regularly scheduled
basis. Since each application is different, the length
of time between regularly scheduled recalibrations can
vary from one installation to the next. In general, the
more frequently a system is checked, the greater the
reliability.
Calibration must be performed:
— When a new system is initially put into service
— When the sensor cell is replaced
— When the hydrophobic filter is cleaned or
replaced.
The following calibration schedule is recommended
when placing a new sensor into operation and will
ensure reliable operation in most applications:
1. One hour after power-up
2. One week later
3. Every 30 days thereafter, or as determined by
the needs of the specific application.
IMPORTANT
To ensure adequate protection, the CO
detection system must be calibrated on a
regularly scheduled basis.
Loss of sensitivity can be caused by various factors.
One common cause is by clogging of the hydrophobic
filter by dirt, oil, paint, etc. Problems of this nature will
not be detected by the controller’s diagnostic circuitry.
While performing calibration, the operator should
examine the hydrophobic filter of the sensor. If it cannot
be cleaned properly, it should be replaced.
For best results, a calibration gas concentration
equal to the high alarm setpoint or 50% full scale is
recommended.
NOTE
If the sensor cell is being replaced, refer to
the “Sensor Cell Replacement” section (under
“Maintenance”) for information regarding cell
replacement and sensor calibration.
CALIBRATION PROCEDURE
Calibration typically requires two people, one person
at the controller and another at the sensor. All adjust-
ments are made automatically by the controller.
1. Be certain that the controller is properly pro-
grammed for the ppm concentration being used
for calibration. (See the “Setpoint Adjustment”
section.) Reprogram the controller if required.
Failure to do so will greatly impair system
response.
2. Be sure that only clean air (0 ppm CO) is present
at the sensor. (The microprocessor begins tak-
ing Zero readings immediately upon entering the
Calibrate mode.) If the possibility of background
gases exists, purge the sensor with clean air to
ensure accurate calibration.
3. Depress and hold the RESET button until the CAL
LED is illuminated and the digital display starts to
flash (approximately 9 seconds).
4. When the Zero calculations are complete (30 sec-
onds minimum), the digital display stops flashing
and reads “00.”
5. Apply the calibration gas to the sensor. The digi-
tal display starts to flash and the value indicated
on the display rises. The bar graph display also
indicates the level of gas at the sensor, but does
not flash.
6. When the microprocessor has completed the
Span adjustments (30 seconds minimum), the
digital display stops flashing.
7. Remove the calibration gas. When the gas level
falls below the lowest alarm setpoint, the control-
ler automatically exits the Calibrate mode. All
outputs and indicators return to normal operation.
If the operator fails to complete the calibration procedure
or if the sensitivity of the sensor has deteriorated to
the extent that calibration cannot be successfully
completed, a calibration fault (“F2X” status) will be
generated and the system will automatically revert back
to the former calibration settings (after 10 minutes or
when the gas level drops below the lowest setpoint).
If a successful calibration cannot be accomplished,
replace the sensor cell and recalibrate.
If the microprocessor determines that the sensor cell
is approaching the end of its useful life, “F10” will be
indicated on the digital display. This does not indicate
a system malfunction, but is intended simply to make
the operator aware of this condition. A successful
calibration can still be performed. Press RESET after
completing calibration to clear the display.

95-84102.1 18
CURRENT OUTPUT CALIBRATION
The 4 to 20 ma output is calibrated at the factory
to provide a degree of accuracy that is satisfactory
for most applications. However, the highest level of
accuracy can be obtained by performing the follow-
ing procedure.
1. A dc current meter capable of measuring 4 to 20
ma must be connected to the current loop output.
This can be accomplished by connecting a dc
ammeter in series with the load or by connecting
a digital dc voltmeter across a known load resis-
tance and calculating the current flow using the
formula:
I = voltage/load resistance.
2. Press and hold the SET button, then immediately
press the RESET button. (The RESET button must
be pressed within one second of pressing the
SET button.) Release both buttons. The Low LED
flashes slowly while the system generates a 4 ma
output.
3. Press the RESET (increase) or SET (decrease)
button to obtain a 4.0 ma reading on the meter.
(Holding the button will cause the output to
change rapidly.)
4. When no adjustments have been made for 7 sec-
onds, the controller automatically switches to a 20
ma output. This is indicated by a flashing High
LED. Press the appropriate button to obtain a
20.0 ma reading.
5. When no adjustments have been made for 7 sec-
onds, the controller generates the current output
level for the calibrate mode. This is indicated by
a flashing CAL LED. Press the appropriate button
to obtain the desired current output level for the
calibrate mode. (The default level is 4.0 ma.)
6. When no changes have been made for 7 sec-
onds, the system automatically returns to the
Normal operating mode and saves the data in
non-volatile memory.
7. Remove the meter from the system output and
reconnect the outputs for normal operating condi-
tions.
Section IV
System Maintenance
ROUTINE MAINTENANCE
To ensure reliable protection, it is important to check
and calibrate the CO detection system on a regularly
scheduled basis. The frequency of these checks
is determined by the requirements of the particular
installation.
MANUAL CHECK OF OUTPUT DEVICES
Fault detection circuitry continuously monitors for
problems that could prevent proper system response.
It does not monitor external response equipment
or the wiring to these devices. It is important that
these devices be checked initially when the system
is installed, as well as periodically during the ongoing
maintenance program.
CHECKOUT IN NORMAL MODE
The system must be checked periodically in the Normal
mode to ensure that those items not checked by the
controller diagnostic circuitry (such as output relays) are
functioning properly.
CAUTION
Be sure to secure all output devices that are
actuated by the system to prevent unwanted
activation of this equipment, and remember
to place these same output devices back into
service when the checkout is complete.
HYDROPHOBIC FILTER
The hydrophobic filter on the front of the sensor housing
protects the sensor cell from contaminants in the
environment. The operator should frequently inspect
the hydrophobic filter for cleanliness. A dirty filter can
significantly reduce the amount of CO gas that is able to
reach the sensor cell, thereby impairing the ability of the
system to respond to a hazardous condition. If the filter
becomes dirty and cannot be properly cleaned or if it is
damaged, it must be replaced. Do not use solvents to
clean the filter.
To replace the hydrophobic filter, simply unscrew the
existing filter from the housing, then replace it with a
new filter. Use care not to over tighten.
NOTE
A dirty hydrophobic filter can adversely affect the
response of the sensor by blocking the flow of
gas to the sensor cell. If the detector cannot be