RKI Instruments 65-2336RKSS User Manual

65-2336RKSS

Carbon Monoxide Transmitter

Part Number: 71-0345
Revision: P1
Released: 10/21/14

Operator’s Manual

RKI Instruments, Inc.

www.rkiinstruments.com

WARNING

Read and understand this instruction manual before operating
detector . Improper use of the dete ctor could result in bodily harm
or death.

Periodic calibration and maintenance of the detector is essential
for proper operation and correct readings. Please calibrate and
maintain this detector regularly! Frequency of calibration
depends upon the type of use you have and the sensor types.
T ypical calibration frequencies for most applications a re between
3 and 6 months, but can be required more often or less often
based on your usage.

65-2336RKSS CO Transmitter

Product Warranty

RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in
materials, workmanship, and performance for a period of one year fr o m date of shipment
from RKI Instruments, Inc. Any parts found defective withi n tha t period will be repaired
or replaced, at our option, free of charge. This warranty does not apply to those items
which by their nature are subject to deterioration or consumption in normal ser v ice, and
which must be cleaned, repaired, or replaced on a routine basis. Examples of such items
are:

W arranty is voided by abuse including mechanical damage, alteration, rough handling, or
repair procedures not in accordance with the operator’s manual. This warranty indicates
the full extent of our liability , a nd we are not r esponsible for removal or r eplacement costs,
local repair costs, transportation costs, or contingent expenses incurred without our prior
approval.

a) Absorbent cartridges d) Batteries
b) Pump diaphragms and valves e) Filter elements
c) Fuses

THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER
WARRANTIES AND REPRESENTATIONS, EXPRESSED OR IMPLIED,
AND ALL OTHER OBLIGATIONS OR LIABILITIES ON THE PART OF
RKI INSTRUMENTS, INC. INCLUDING BUT NOT LIMITED TO, THE
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. IN NO EVENT SHALL RKI INSTRUMENTS,
INC., BE LIABLE FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
LOSS OR DAMAGE OF ANY KIND CONNECTED WITH THE USE OF
ITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO FUNCTION OR
OPERATE PROPERLY.

This warranty covers instruments and parts sold to users by authorized distributors,
dealers, and representatives as appointed by RKI Instruments, Inc.

We do not assum e i ndemnification fo r a ny accident or dama g e ca u s e d by the operation of
this gas monitor, and our warranty is limited to the replacement of parts or our complete
goods.

65-2336RKSS CO Transmitter

Table of Contents

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

CO Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Mounting the CO Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Wiring the CO Transmitter to a Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Replacing Components of the CO Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Preparing for Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Setting the Zero Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Setting the Response Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Returning to Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

65-2336RKSS CO Transmitter

Overview

!

This instruction manual describes the 65-2336RKSS carbon monoxide (CO) transmitter.
This manual also describes how to insta ll, start up, configure, maintain, and calibrate the
transmitter when using it with a gas monito ring controller. A parts list at the end of this
manual lists replacement parts and accessories for the CO transmitter. See the controller
operator’s manual for information specific to the controller.

Specifications

WARNING: Do not use this product in a manner not specified in thi s instruction

manual.

Table 1 lists specifications for the CO transmitter.

Table 1: Specifications

Target Gas Carbon Monoxide
Area Classification Explosion-proof for Class I, Groups B, C, and D
Temperature Code T6
Installation Category Installation Category 1. Signal level, special equipm ent or parts of

Input Voltage 11 VDC - 30 VDC
Sampling Method Diffusion
Signal Output 4 to 20 mA
Detection Range 0 to 300 ppm (parts per million)
Accuracy ± 5% of reading or ± 5 ppm CO (whichever is greater)
CO Detector Signal Output 0.3 mA at 0 ppm CO nominal

Response Time 90% in 30 seconds
Operating Temperature 23°F to 104°F (-5°C to 40°C)

NOTE: The following symbol on the detector label is a caution to the user to refer to this

documentation for installation and operation instructions:

equipment, telecommunication, electronic, etc., with smaller
transient overvoltages than Installati on Category (Overvoltage
Category) II (ref. IEC 664).

2.5 mA at 300 ppm CO nominal

WARNING: When using the 65-2336RKSS, you must follow the instructions and

warnings in this manual to assure proper and safe opera tion of the
65-2336RKSS and to minimize the risk of personal injury. Be sure to
maintain and periodically calibrate the 65-2336RKSS as described in this
manual.

65-2336RKSS CO Transmitter • 1

Description

r

Fa ctory Ad just Pot

This section describes the components of the CO transmitter. The CO transmitter is a 4 to
20 mA type detector head. It consists of the CO detector, amplifier, and junction box.

Controller
Terminal
Strip

Span Pot

10 0m V - 500m V

Range

Zero Pot

+ Test Point (Red)

- Test Poi nt (B l ack)

Amplifie

SPAN

ZERO

S

SIG/PWR

TO X IC OX Y

Detector
Terminal
Strip

J-Box

2 • 65-2336RKSS CO Transmitter

CO
Detector

Figure 1: CO Transmitter Component Location

CO Detector

The CO detector consists of the detector housing body, detector housing cap, cap gasket,
plug-in sensor, and the charcoal filter.

Detector Housing Body

Cap Gasket

Plug-In CO Sensor

Rub ber Boot With
Charcoal Filter

Detector Hou sing Cap

Flame Arrestor
Guard

Figure 2: CO Detector Component Location

Detector Housing Body

The detector housing body protects the electronic components within the housing. Use the
mounting threads at the top of the housing to screw the CO detector into the 3/4” NPT
hub on the bottom of the junction box. Two wires extend from the top of the detector
housing body. Use these wires to connect the CO detector to the amplifier. One of the
wires is red and one of the wires is black.

The housing includes a four-socket pattern. This socket pattern accepts the sensor’s four
pins to secure the sensor within the detector housing. A pre-amplifier, located between the
sockets and two interconnect wires, conditions the sensor’s signal before the signal
reaches the controller.

Housing Cap & Cap Gasket

The housing cap screws onto the detector housing. It retains the plug-in sensor and
protects it from damage. The housing cap also includes a flame arrestor which contains
any sparks that may occur within the detector and a flame arrestor guard which protects
the flame arrestor fro m damage. Unscrew the detector cap to access the plug-in sensor for
maintenance or replacement. A cap gasket seals the interface between the housing and
cap.

Plug-In CO Sensor

The sensor is secured within the detector assembly by the housing cap. Through a series
of chemical and electrical reactions, the sensor produces an electrical output that
corresponds to the detection range of the transmitter.

Charcoal Filter

The disc-shaped charcoal filter is secured to the face of the CO sensor with a rubber boot.
The charcoal filter prevents interference gas e s ( hydrogen sulfid e [H

S] and certain hydro-

2

carbons) from producing false CO readings.

65-2336RKSS CO Transmitter • 3

Amplifier

The amplifier converts the electrical output from the detector to a 4 to 20 mA signal that
corresponds to the detection range and transmits the signal to a gas monitoring controller .
A foam gasket that orients the amplifier and keeps it from rotating is installed on the
bottom of the amplifier. The amplifier includes the controller terminal strip, detector
terminal strip, zero pot, span pot, and test points (see Figure 1).

Controller Terminal Strip

The controller terminal strip is a two position plug-in style terminal s trip located at the
top edge of the amplifier. Use the controller terminal strip to wire the amplifier to a
controller.

Detector Terminal Strip

The detector terminal strip is a four position plug-in style terminal strip located below the
controller terminal strip. Two of the positions are for use with an oxygen detector and are
not used in the CO transmitter. Use the two detector terminal strip positions that are
labeled “TOXIC” to connect the detector to the amplifier.

NOTE: The detector is factory-wired to the detector terminal strip. See “Wiring the CO

Transmitter to a Controller” on page 6 for all wiring procedures related to the
transmitter.

Zero Pot

The zero pot is located in the upper left corner of the amplifier (see Figure 1). Use a small
flat blade screwdriver to turn the zero pot’s adjustment screw and adjust th e amplifier’s
zero (CO free) output during the start-up and calibration procedure. Turn the adjustment
screw clockwise to increase the zero output and counterclockwise to decrease the zero
output.

Span Pot

The span pot is located to the right of the zero pot (see Figure 1). Use a small flat blade
screwdriver to turn the span pot’s adjustment screw an d adjust the amplifier’s response
output during the start up and calibration procedure. Turn the adjustment screw
clockwise to increase the response output and counterclockwise to decrease the response
output.

CAUTION: The amplifier includes an additional pot. It is factory-set. Do not adjust it .

Test Points

The test points are on the left side of the amplifier (see Figure 1). The test points produce a
100 mV to 500 mV output that corresponds to the transmitter’s 4 to 20 mA output. Use the
test points and a voltmeter to measure the amplifier’s output during the start-up and
calibration procedures. The black test point in the lower left corner is the negative (-) test
point and the red test point below the zero pot is the positive (+) test point.

Junction Box

The stainless steel, corrosion resistant junction box allows you to install the detector at a
mounting site that is remote from a controller, and it protects the amplifier and wiri ng
connections made to the amplifier. Two conduit hubs allow you to mount the detector to
the junction box and connect the wiring from the detector to a controller. An O-ring seals
the interface between the junction box cover and the junction box base.

4 • 65-2336RKSS CO Transmitter

Installation

The amplifier is factory installed in the junction box. A cover on the front of the junction
box allows access to the interior of the junction box. A locking set screw on the junction
box cover allows you to secure the junction box cover and prevent it from being removed.

This section describes procedures to mount the CO transmitter in the monitoring
environment and wire the transmitter to a controller.

Mounting the CO Transmitter

1. Select a mounting site that is representative of the monitoring environment. Consider
the following when you select the mounting site:

• Select a site where the transmitter is not likely to be bumped or disturbed. Make

sure there is sufficient room to perform start-up, maintenance, and calibration
procedures.

• Select a site that is at normal breathing level.

8.20 max

3.66

3.15

2.40

3.34

3/4 NPT
Female,
2X

.20 Dia. x .45
Slot, 2X

J-Box

CO Detector

1.10

Figure 3: Mounting the CO Transmitter

2. At the monitoring site you select, hang or mount the junction box with the detector
facing down (see Figure 3).

65-2336RKSS CO Transmitter • 5

Wiring the CO Transmitter to a Controller

WARNING : Always verify that power to the co ntroller is off before you make wiring

connections.

1. Turn off the controller.

2. Turn off power to the controller.

3. Remove the junction box cover.

4. The detector leads are factory wired. Verify that the detector leads are wired to the
amplifier’s detector terminal strip as shown in Figure 4.

5. To gai n a ccess to a plug-in terminal strip for wiring, pull it out of its sock et by
grasping the terminal strip and pulling. The detector terminal strip is keyed so that
the controller and detector terminal strips cannot be reversed inadvertently.

WARNING: To maintain the explosion proof classification of the CO detector/junction

box combination, a conduit seal must be used within 18 inches of the
junction box conduit hub used for wir ing to the controller.

6. Guide either a two-conductor, shielded cable, or two wires in conduit through the top
conduit hub of the junction box.

7. Pull out the controller terminal strip, and connect the two wires to the terminal strip
as follows (see Figure 4):

• Connect the positive wire to the SIG/PWR “+” terminal.

• Connect the signal wire to the SIG/PWR “S” terminal.

CAUTION: If shielded cable is used, leave the cable shield ’s drain wire disconnected and

insulated at the transmitter. You will connect the opposite end of the cable’s drain
wire to the controller’s chassis (earth) ground.

8. Reinstall the controller terminal strip into its socket.

9. Secure the junction box cover to the junction box.

10. Route the cable or wires leading from the CO transmitter through one of the conduit
hubs at the controller housing.

CAUTION: Do not route power and transmitter wiring through the same controller conduit hub.

The power cabl e may disrupt the transmission o f the transmitte r signal to the
controller.

11. Connect the wires to the applicable detector/transmitter terminal strip at the
controller as shown in Figure 4.

6 • 65-2336RKSS CO Transmitter

Controller Detector/

Transmitter Terminals,

Typical Designations

Controller Housing

S

+

Cable Shield

SPAN

ZERO

S

TO X IC OX Y SIG/P WR

Black

J-Box

Red

CO Detector

Figure 4: Wiring the CO Transmitter to a Controller

12. If shielded cable is used, connect the cable’s drain wire to an available chassis (earth)
ground at the controller. RKI controllers typically have a ground stud that can be used
to ground the cable’s drain wire.

65-2336RKSS CO Transmitter • 7

Start Up

This section describes procedures to start up the CO transmitter and place the transmitter
into normal operation.

Introducing Incoming Power

1. Complete the installation procedures described earlier in this manual.

2. Verify that the power wi ring to the controller is correct and secure. Refer to the
controller operator’s manual.

3. Turn on power to the controller.

4. Turn on the controller.

5. Verify that the controller is on an d op erating properly. Refer to the controller
operator’s ma nual.

CAUTION: Allow the transmitter to warm up for 5 minutes before you continue with the next

section, “Setting the Zero Signal”.

Setting the Zero Signal

WARNING: Do not remove the detector housing cap or junction box cover while the

circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap and junction box cover tightly closed during
operation.

NOTE: If you can verify that the detector is in a fresh air environment (environment

known to be of normal oxygen content and free of toxic and combustible gases),
it is not necessary to apply zero air when verifying or setting the fresh air
reading.

The procedure below describes applying zero emission air, usually called zero air , using a
calibration kit that includes a calibration cup, calibration gas, sample tubing, and a fixed
flow regulator with an on/off knob. RKI Instruments, Inc. recommends using a 0.5 LPM
(liters per minute) fixed flow regulator.

1. Unscrew and remove the junction box cover from the junction box.

2. Set a voltmeter to measure in the millivolt (mV) range.

3. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead
into the red (+) test point; plug the negative lead into the black (-) test point.

4. Screw the calibration cup onto the bottom of the CO detector.

5. Screw the regulator into the zero air calibration cylinder.

6. Use the sample tubing to conn ect the regulator to the calibrat ion cup.

7. Turn the regulator’s on/off knob counterclockwise to open it. Gas will begin to flow.

8. Allow the gas to flow fo r two minutes.

9. Verify a voltmeter reading of 100 mV (±2 mV).

10. If necessary, use a small flat-blade screwdriver to adjust the zero pot until the
voltmeter reading is 100 mV (±2 mV).

8 • 65-2336RKSS CO Transmitter

11. Turn the regulator’s on /off knob clockwise to close it.

12. Unscrew the calibration cup from the detector.

13. Unscrew the regulator from the zero air calibration cylinder. For convenience, leave

14. Store the components of the calibration kit in a safe and conve nient place.

15. Remove the voltmeter leads from the test points.

16. Secure the junction box cover to the junction box.

Maintenance

This section describes maintenance procedures. It includes preventive maintenance,
troubleshooting, and component replacement procedures.

Preventive Maintenance

This section describes a preventive maintenance schedule to ensure the optimum
performance of the CO transmitter. It includes daily, monthly, and quarterly procedures.

Daily

Verify a display reading of 0 ppm CO at the controller. Investigate significant changes in
the display reading.

the sample tubing connected to the regulator and the calibration cup.

Monthly

This procedure describes a test to verify that the CO transmitter responds properly to
carbon monoxide. It describes the test using a calibration kit that includes a ca libration
cup, calibration gas, sample tubing, and a fixed f low regulator with an on/off knob.

NOTE: Performing a response test on the CO transmitter may cause alarms. Be sure to

put the controller into its calibration mode or disable external alarms before
performing this test.

Preparing for the response test

1. Place the controller into its calibration program or disable external alarms.

2. Verify that the controller display reading for the channel you are testing is 0 ppm.
If the display reading is not zero, set the zero reading of the transmitter as described

in the Start Up section of this manual, then continue this procedure.

WARNING: Do not remove the detector housing cap or junction box cover while the

circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap and junction box cover tightly closed during
operation.

3. Unscrew and remove the junction box cover.

4. Set a voltmeter to measure in the millivolt (mV) range.

5. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead
into the red (+) test point; plug the negative lead into the black (-) test point.

6. Use the following formula to determine the correct test points output for the test
sample.

Output (mV) = (calibrating sample/fullscale) X 400 + 100

65-2336RKSS CO Transmitter • 9

For example, with a test sample of 50 ppm CO and a fullscale setting of
300 ppm, the correct output is 167 mV.

167 (mV) = (50/300) X 400 +100

7. Screw the regulator into the calibration cylinder.

8. Use the sample tubing to conn ect the regulator to the calibrat ion cup.

Performing the response test

1. Turn the regulator’s on/off knob counterclockwise to open the regulator. Gas will
begin to flow.

2. Allow the gas to flow for two minutes, then verify that the reading is within ± 20% of
the response reading you determined earlier.

NOTE: If the readings are not within ± 20% of the correct response reading, calibrate the

affected transmitter(s) as described in “Calibration” on page 14.

3. Turn the regulator’s on/off knob clockwise to close the regulator.

4. Unscrew the regulator from the calibration cylinder.

5. Unscrew the calibration cup from the CO detector.

6. Remove the voltmeter leads from the amplif ier test points.

7. Reinstall the junctio n box cover.

8. When the controller displa y reading falls below the alarm setpoints, return the
controller to normal operation.

9. Store the components of the calibration kit in a safe p l ace.

Quarterly

Calibrate the CO transmitter as described in “Calibration” on page14 of this manual. See
the calibration frequency discussion in “Calibration Frequency” on page 14 to determine
if a quarterly calibration schedule fits your needs.

Troubleshooting

The troubleshooting guide describes symptoms, probable causes, and recommended
action for problems you may encounter with the CO transmitter.

NOTE: This troubleshooting guide describes transmitter problems only. See the

controller instruction manual for problems you may encoun ter with the
controller.

10 • 65-2336RKSS CO Transmitter

.

Table 2:Troubleshooting the CO Transmitter

Condition Symptom(s) Probable Causes Recommended Action

Fail Condition Controller indicates a

fail condition.

Slow or No
Response/
Difficult or
Unable to
Calibrate

• Transmitter responds
slowly or does not
respond to response
test.

• Unable to accurately
set the zero or
response reading
during calibration.

• Transmitter requires
frequent calibration.

Note: Under “normal”
circumstances, the
transmitter requires
calibration once every 3
months.

Some applications
may require a more
frequent calibration
schedule.

• The transmitter wiring
to the controller is
disconnected or
misconnected.

• The plug-in sensor is
not properly plugged
into the sockets in the
detector housing body.

• The wiring from the
detector to the
amplifier is
disconnected or
misconnected.

• The transmitter’s zero
reading is low enough
to cause a fail
condition.

• The transmitter is
malfunctioning.

• The calibration cylinder
is low, out-dated, or
defective.

• The flame arrestor in
the detector housing
cap is wet or clogged
with dirt or other
particulates.

• The calibration gas is
not an appr opriate
concentration.

• The transmitter is
malfunctioning.

1. V erify that the transmitter wiri ng to the
controller is correct and secure.

2. Confirm that the plug-in sensor is
installed properl y.

3. V erify that th e wiring from the detector
to the amplifier is correct and secure.

4. Perform a zero adjustment. A full
calibration is recommended.

5. If the fail condition continues, replace
the plug-in sensor as described later
in this section.

6. If the fail condition continues, contact
RKI for further instruction.

1. Verify that the calibration cylinder
contains an adequate supply of a
fresh test sample.

2. Check the detector housing cap to
determine if the flame arrestor is wet
or dirty. Clean if necessary.

3. Verify that the calibration gas
concentration is appropriate for the
transmitter. Zero emission air (20.9%
oxygen) is normally used for a zero
adjustment if the environment is
suspect and 50 PPM CO in air is
normally used for a response
adjustment.

4. If the calibration/response difficulties
continue, replace the plug-in sensor
as described later in this section.

5. If the calibration/response difficulties
continue, contact RKI for further
instruction.

Unexplained
Upscale
Readings or
Alarms

• Controller indicates a
CO reading that
cannot be verified.

• CO alarms occur at
the controller that
cannot be explained.

• Charcoal filter is
saturated and no
longer scrubbing out
interfering gases.

1. Replace char co al filter.

2. If difficulties continue, contact RKI for
further instructions.

65-2336RKSS CO Trans mitt er • 11

Replacing Components of the CO Transmitter

This section includes a procedure to replace the CO plug-in sensor, charcoal filter, and
amplifier. A procedure to replace the entire detector assembly is at the end of this section.
In most cases, it is not necessary to replace the entire detector assembly.

Replacing the Plug-In CO sensor

CAUTION: The sensor contains electrolyte which is a dilute acid. Do not dis assemble the sens o r

when replacing it with a new one. If sensor electrolyte comes in co ntact with your
skin, wash affected area thoroughly with soap and water.

1. Turn off the controller.

2. Turn off or unplug power to the contro ller.

3. Unscrew the detector housing cap from the detector housing body. Make sure not to
lose the cap gasket.

4. Unplug and remove the CO sensor with the boot and charcoal filter attached.

5. Remove the rubber boot and charcoal filter from old sensor.

6. Install the rubber boot with charcoal filter onto the replacement sensor’s face.

7. Carefully plug the replacement sensor into the fou r-socket pattern that is located in
the detector housing.

8. Make sure the cap gasket is in place and screw the detector housing cap back onto the
detector housing body.

9. Turn on or plug in power to the controller.

10. Turn on the controller and place into normal operation.

CAUTION: Allow the r ep la cem ent sens or to w arm up for 5 m inu tes before you continue with the

next step.

11. Calibrate the transmitter as described in “Calibration” on page 14.

Replacing the Charcoal Filter

1. Turn off the controller.

2. Turn off or unplug power to the contro ller.

3. Unscrew the detector housing cap from the detector housing body.

4. Unplug and remove the CO sensor with the boot and charcoal filter attached.

5. Remove the rubber boot that secures the charcoal filter to the CO sensor.

6. Remove the charcoal filter from the rubber boot.

7. Place the replacement filter in the rubber boot in the same position as the filter you
removed in the previous step.

8. Reinstall the rubber boot with charcoal filter to the CO sensor.

9. Carefully plug the replacement sensor into the fou r-socket pattern that is located in
the detector housing.

10. Make sure the cap gasket is in place and screw the detector housing cap back onto the
detector housing body.

11. Turn on or p lug in power to the controller.

12 • 65-2336RKSS CO Transmitter

12. Turn on the controller and place into normal operation.

Replacing the CO Detector

NOTE: In most cases, it is only necessary to replace the plug-in CO sensor.

1. Turn off the controller.

2. Turn off or unplug power to the contro ller.

3. Remove the junction box cover.

4. Remove the detector terminal strip from its socket.

5. Disconnect the detector leads from the detector terminal strip. Note the position of the
color-coded leads as you remove them.

6. Unscrew the detector from the junction box conduit hub.

7. Guide the detector leads of the replacement detector through the bottom conduit hub
of the junction box, then screw the mounting threads of the detector into the conduit
hub. If necessary for environmental conditions, apply thread sealant or teflon tape to
the hub and/or detector threads to seal them.

8. Connect the detector leads to the appropriate detector terminal strip terminals.
Connect the red wire to the terminal labeled TOXIC+ and the black wire to the
terminal labeled TOXIC-. See Figure 4 for the detector wiring connections to the
amplifier.

9. Reinstall the detector terminal strip into its socket.

10. Turn on or plug in power to the co ntroller.

11. Turn on the controller and place it into normal operation.

CAUTION: Allow the replacem ent detector to warm up for 5 minutes before you co ntinue with

the next step.

12. Calibrate the replacement detector as described in “Calibration” on page 14.

13. Secure the junction box cover to the junction box.

Replacing the Amplifier

1. Turn off the controller.

2. Turn off or unplug power to the contro ller.

3. Remove the junction box cover.

4. Unplug the detector terminal strip and controller terminal strip from their sockets.
You may leave the wires connected to the terminal strips.

5. Unscrew and remove the screw with th e flat and lock washers that secures the
amplifier to the junction box. The screw is at the bottom right of the amplifier.

6. Remove the old amplifier.

7. Place the new amplifier in the same position as the old amplifier. A foam gasket that
orients the amplifier and keeps it from rotating is installed on the bottom of the
amplifier. Make sure the amplifier is seated flat in the junction box.

8. Install the new amplifier into the junction box with the screw, lock washer, and flat
washer you removed in Step 5.

9. Install the detector and controller terminal strips into th e ir sockets on the new

65-2336RKSS CO Trans mitt er • 13

amplifier as shown in Figure 4. If controller leads or detector leads were removed
during this procedure, refer to Figure 4 for the det ect or and amplifier connections.

NOTE: When a transmitter is first powered up with a new amplifier, the initial output

may be either high or below zero depending on the setting of the zero pot. Be
sure to make arrangements so that this does not cause unwanted alarms.

10. Turn on or plug in power to the co ntroller.

11. Turn on the controller and place it into normal operation.

12. Allow the transmitter to warm up for 5 minutes.

13. Calibrate the CO transmitter as described in “Calibration” on page 14.

Calibration Frequency

Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 months is adequate for most CO transmitter applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the CO transmitter.

If an application is not very demanding, for example detection in a clean, temperature
controlled environment, and calibration adjustments a re minima l at calibration, then a
calibration frequency of every 6 months is adequate.

Calibration

If an application is very demanding, for example if the environment is not well controlled,
then more frequent calibration than every 3 months may be necessary.

This section describes how to calibrate the CO transmitter. It includes procedures to
prepare for calibration, set the zero reading, set the response reading, an d return to
normal operation. It describes th e te st using a calibration kit that includes a calibration
cup, calibration gas, sample tubing, and a fixed f low regulator with an on/off knob. RKI
Instruments, Inc. recommends using a 0.5 LPM (liters per minute) fixed flow regulat or.

Prepari ng for Ca libration

NOTE: Calibrating the CO transmitter may cause alarms. Be sure to put the controller

into its calibration program or disable external alarms before calibrating.

WARNING: Do not remove the detector housing cap or junction box cover while the

circuits are energized unless the area is determined to be non-hazardous.
Keep the detector housing cap and junction box cover tightly closed during
operation.

1. Unscrew and remove the junction box cover.

2. Set a voltmeter to measure in the millivolt (mV) range.

3. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead
into the red (+) test point; plug the negative lead into the black (-) test point.

4. Use the following formula to determine the correct test points output for the

14 • 65-2336RKSS CO Transmitter

calibrating sample.

Output (mV) = (calibrating sample/fullscale) X 400 + 100

For example, with a calibrating sample of 50 ppm CO and a fullscale setting of
300 ppm, the correct output is 167 mV.

167 (mV) = (50/300) X 400 +100

5. Screw the calibration cup onto the detector housing.

Setting the Zero Reading

NOTE If you can verify that the CO transmitter is in a fresh air environment, you do not

need to apply zero air to the detector before adjusting the zero reading.

1. Screw the regulator into the zero air calibration cylinder.

2. Use the sample tubing to conn ect the regulator to the calibrat ion cup.

3. Turn the regulator knob counterclockwise to open the regulator.

4. Allow the gas to flow for two minutes, then verify a reading of 100 mV (± 2mV). If
necessary, use the zero pot on the amplifier to adjust the reading to 100 mV (± 2mV).

5. Unscrew the regulator from the zero air calibration cylinder.

6. Leave the sample tubing connected to the regulator and the calibration cup.

Setting the Response Reading

1. Screw the regulator into the calibration cyli nd er. Verify that the calibration gas is
representative of the transmitter’s target gas.

2. Turn the regulator knob counterclockwise to open the regulator.

3. Allow the gas to flow for two minutes, then verify that the reading matches the
response reading (± 2mV) you determined earlier. If necessary, use the span pot on the
amplifier to adjust the reading to match the correct response reading.

4. Turn the regulator knob clockwise to close the regulator.

5. Unscrew the regulator from the calibration cylinder.

Returning to Normal Operation

1. Remove the voltmeter leads from the amplif ier test points.

2. Unscrew the calibration cup from the detector.

NOTE: For convenience, leave the components of the calibration kit connected by the

sample tubing.

3. Secure the junction box cover to the junction box.

4. When the display reading falls below the alarm setpoints, return the controller to
normal operation.

5. Verify that the controller display reading decreases and stabilizes at 0 ppm.

6. Store the components o f the calibration kit in a safe and convenient pl ace.

65-2336RKSS CO Trans mitt er • 15

Parts List

Table 3 lists replacement parts and accessories for the CO transmitter.

Table 3: Parts List

Part Number Description

06-1248RK Sample tubing (order by the foot)
07-0033RK Detector housing cap gasket
07-0203RK Rubber retaining boot (for charcoal filter)
07-7151RK O-ring for junction box
10-5153RK Lid locking set screw for junction box
18-0416RK-11 Junction box with cover, stainless steel
33-7101RK Charcoal filter disk
57-1064RK-03 Amplifier (specify target gas when ordering)
65-2336RKSS CO transmitter (includes detector and amplifier), CSA classified
65-2438 CO replacement detector ass embly (includes sensor), CSA classified
71-0345 65-2336RKSS CO Transmitter Operator’s Manual (this document)
81-0064RK-01 Calibration cylinder, 50 ppm CO in air, 34 liter steel
81-0076RK-01 Zero air calibration cylinder, 34 liter s teel
81-1050RK Regulator with gauge and knob, 0.5 LPM, for 17 liter and 34 liter steel calibration

cylinders
81-1117RK Calibration cup
ES-1531-CO CO replacement sensor

16 • 65-2336RKSS CO Transmitter