RKI Instruments 65-2394RK-CH4-4 User manual

65-2394RK-CH4-4
Combustible Gas Transmitter
Operator’s Manual
Part Number: 71-0277RK
Revision: P1
Released: 4/9/13
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65-2394RK-CH4-4 Combustible Gas Transmitter
WARNING
Read and understand this instruction manual before
operating transmitter. Improper use of the transmitter could
result in bodily harm or death.
Periodic calibration and maintenance of the transmitter is
essential for proper operation and correct readings. Please
calibrate and maintain this transmitter regularly! Frequency
of calibration depends upon the type of use you have and
the sensor types. Typical calibration frequencies for most
applications are between 6 and 12 months, but can be
required more often or less often based on your usage.
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65-2394RK-CH4-4 Combustible Gas 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 from date of shipment
from RKI Instruments, Inc. Any parts found defective within that 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 service, and
which must be cleaned, repaired, or replaced on a routine basis. Examples of such items
are:
Warranty 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, and we are not responsible for removal or replacement costs,
local repair costs, transportation costs, or contingent expenses incurred without our prior
approval.
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 assume indemnification for any accident or damage caused by the operation of
this gas monitor, and our warranty is limited to the replacement of parts or our complete
goods.
a) Absorbent cartridges d) Batteries
b) Pump diaphragms and valves e) Filter elements
c) Fuses
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65-2394RK-CH4-4 Combustible Gas Transmitter
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Combustible Gas Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Calibration Cup/Splash Guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Amplifier Junction Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Detector Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Mounting the Combustible Gas Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Wiring the Detector to the Amplifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Wiring the Amplifier to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing Components of the Combustible Gas Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Determining Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Preparing for Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Setting the Response Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Returning to Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
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65-2394RK-CH4-4 Combustible Gas Transmitter • 1
Overview
This manual describes the 65-2394RK-CH4-4 combustible gas transmitter. This manual
also describes how to install, start up, configure, maintain, and calibrate the transmitter
when it is used with a gas monitoring controller. A parts list at the end of this manual lists
replacement parts and accessories for the combustible gas transmitter.
Specifications
Table 1 lists specifications for the combustible gas transmitter.
WARNING: When using the 65-2394RK-CH4-4, you must follow the instructions and
warnings in this manual to assure proper and safe operation of the
65-2394RK-CH4-4 and to minimize the risk of personal injury. Be sure to
maintain and periodically calibrate the 65-2394RK-CH4-4 as described in
this manual.
Table 1:Specifications
Description Specification
Target Gas 65-2394RK-CH4-4: Methane (CH4)
Area Classification Explosionproof for Class I, Groups B, C, and D
Sampling Method Diffusion
Signal Output 4 to 20 mA
Detection Range 0 to 100% LEL
Response Time 90% in 45 seconds
Operating Temperature -4°F to 122°F (-20°C to 50°C)
Accuracy ± 5% of reading or ± 2% of full scale (whichever is greater)
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2 • 65-2394RK-CH4-4 Combustible Gas Transmitter
Description
The 65-2394RK-CH4-4 combustible gas transmitter utilizes an infrared type of detector
which has some advantages over a catalytic type of combustible detector. The infrared
detector will generally have a longer service life than a catalytic detector, it will require
calibration less often, and it can detect combustible gas even if there is no oxygen in the
sample which allows detection of combustible gas in an inert atmosphere.
This section describes the components of the combustible gas transmitter. The transmitter
is a 4 - 20 mA type detector head. It consists of the combustible gas detector, calibration
cup/splash guard, amplifier, the amplifier junction box, and the detector junction box.
The two junction box configuration is intended for situations where the detector needs to
be installed at an inaccessible location. The detector junction box can be installed at the
inaccessible location and the amplifier junction box can be installed in a more readily
accessible area.
Figure 1: Combustible Gas Transmitter Component Location
GWRB
Sensor
Current
mA SPAN
ZERO
Amplifier
Factory Adjust
Pot
57-1053RK
S
S2 001
Jumper Pins,
Factory Use
Only
Detector Terminal
Strip
- Test Point
+ Test Point
Zero Pot
Span Pot
Factory Adjust Pot
Terminal Strip
IR LEL Detector
Detector J-Box
Amplifier J-Box
LEL PWR/SIG
Calibration Cup/Splash Guard
Controller Terminal
Strip
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65-2394RK-CH4-4 Combustible Gas Transmitter • 3
Infrared LEL Detector
The infrared LEL detector is made up of a miniature infrared combustible gas LEL
detector housed and encapsulated in a pipe nipple. The pipe nipple has 3/4” NPT threads
on each end and a 1 1/4” hex that allows removal or installation of the detector with a
wrench. A porous flame arrestor that is coated with a hydrophobic film that repels liquids
is on one end of the detector and allows sample gas to enter the detector. Four color coded
leads, red, white, green, and black, extend from the other end of the detector. The leads
allow you to connect the detector to the amplifier.
Calibration Cup/Splash Guard
A calibration cup/splash guard is installed on the IR LEL detector. A fitting at the bottom
of the calibration cup/splash guard allows a length of tubing to be connected for
calibration and routed to a more easily accessible location. The calibration cup/splash
guard also protects the detector.
Amplifier
The amplifier is located in the amplifier junction box. 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. A label on
the amplifier indicates the detector drive current. This drive current is factory set and is
dictated by the combustible gas to which the detector is calibrated. Consult RKI
Instruments, Inc. if you plan to change the calibration gas for the transmitter, for example
from a methane calibration to a hexane calibration. The amplifier includes the detector
terminal strip, controller terminal strip, span pot, zero pot, and test points (see Figure 1).
Controller Terminal Strip
The controller terminal strip is a three position plug-in style terminal strip located near the
top of the amplifier. Use the controller terminal strip to wire the combustible gas
transmitter 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. Use the detector terminal strip to connect the IR LEL detector to
the amplifier.
NOTE: See “Wiring the Detector to the Amplifier” 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 the amplifier’s
zero (fresh air) output during the start-up and calibration procedures. Turn the adjust-
ment 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 and adjust the amplifier’s gas
response output during the calibration procedure. Turn the adjustment screw clockwise to
increase the gas response and counterclockwise to decrease the gas response.
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4 • 65-2394RK-CH4-4 Combustible Gas Transmitter
CAUTION: The amplifier includes two additional potentiometers. They are factory-set. Do not
adjust them.
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.
Amplifier Junction Box
The amplifier junction box protects the amplifier and wiring connections made to the
amplifier. Use the top 3/4’’ conduit hub to connect wiring from the amplifier to the
controller. Use the bottom 3/4” conduit hub to wire the remotely installed IR LEL
detector. Use the cover on the front of the junction box to access the interior of the junction
box. The amplifier is factory installed in the junction box. Three spacers installed on the
back of the junction box controls the distance of the junction box from a mounting surface.
Detector Junction Box
The detector junction box is intended to be installed remotely from the amplifier junction
box. The IR LEL detector is factory installed in the bottom 3/4” conduit hub. A terminal
strip is provided for wiring connections and the detector is factory wired to one side of
this terminal strip. The other side of the terminal strip is for user-supplied wiring to the
detector terminal strip located in the amplifier junction box. This wiring should go
through the top 3/4” conduit hub. Three spacers installed on the back of the junction box
controls the distance of the junction box from a mounting surface.
Installation
This section describes procedures to mount the combustible gas transmitter in the
monitoring environment and wire the transmitter to a controller.
Mounting the Combustible Gas Transmitter
1. Select a mounting site that is representative of the monitoring environment. Consider
the following when you select the mounting site.
• For the amplifier junction box, select a site where the junction box is not likely to
be bumped or disturbed. Make sure there is sufficient room to perform start-up,
maintenance, and calibration procedures. The site should be easily accessible.
• For the detector junction box, select a site where the target gas is likely to be found
first. For lighter gases, mount the detector near the ceiling; for heavier gases,
mount the detector near the floor.
• The junction boxes should be mounted no further than 200 feet from each other.
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65-2394RK-CH4-4 Combustible Gas Transmitter • 5
Figure 2: Mounting the Combustible Gas Transmitter
2. At the monitoring site you select, hang or mount the detector junction box with the
detector facing down (see Figure 2).
3. Install 3/16 inch I.D. flexible polyurethane tubing to the fitting at the bottom of the
calibration cup/splash guard and route it to an accessible area that is close to the
amplifier junction box. See the “Parts List” on page 18 for available tubing.
.382.70
J-Box
Rubber
Spacer,
3X
.75
3/4 NPT
Female
3.65
Calibration
Cup/Splash
Guard
IRLEL
Detector
9.00 MAX
5.25
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6 • 65-2394RK-CH4-4 Combustible Gas Transmitter
Wiring the Detector to the Amplifier
WARNING: Always verify that the power to the controller is off before you make
wiring connections.
1. Confirm that no power is being applied to the amplifier. If the amplifier has already
been connected to a controller, turn off the controller and turn off or unplug power to
the controller.
2. Remove the detector junction box’s cover from the junction box.
3. Remove the amplifier junction box’s cover from the junction box.
4. Guide a four-conductor, shielded cable or four wires in conduit through the top
conduit hub of the detector junction box. To make wiring more convenient, use wire
colors that correspond to the detector wire colors: red, white, green, and black.
NOTE: Consult RKI Instruments, Inc. for cable lengths longer than 200 feet.
5. Connect the detector leads to the terminal block in the detector junction box.
6. Secure the detector junction box’s cover to the junction box.
7. Guide the other end of the four-conductor, shielded cable or four wires in conduit
through the bottom conduit hub of the amplifier junction box.
8. To gain access to a plug-in terminal strip for wiring, pull it out of its socket by
grasping the terminal strip and pulling. The detector strip is keyed so that the
controller and detector terminal strips cannot be reversed inadvertently.
9. Pull out the detector terminal strip and connect the four wires to the terminal strip as
follows (see Figure 3).
• Connect the wire corresponding to the detector’s red wire to the LEL “R”
terminal.
• Connect the wire corresponding to the detector’s white wire to the LEL “W”
terminal.
• Connect the wire corresponding to the detector’s green wire to the LEL “G”
terminal.
• Connect the wire corresponding to the detector’s black wire to the LEL “B”
terminal.
CAUTION: If shielded cable is used, leave the cable shield’s drain wire disconnected and
insulated at the detector junction box. You will connect the opposite end of the cable’s
drain wire to the amplifier junction box’s chassis (earth) ground.
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