RKI Instruments 65-2619RK-CH4-4 User manual

65-2619RK-CH4-4
M2 Transmitter
Operator’s Manual
Part Number: 71-0289RK
Revision: 0
Released: 12/27/13
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
WARNING
Read and understand this instruction manual before
operating instrument. Improper use of the gas monitor
could result in bodily harm or death.
Periodic calibration and maintenance of the gas
monitor is essential for proper operation and correct
readings. Please calibrate and maintain this instrument
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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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
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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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About the M2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About this Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
External Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Internal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 3: Installation & Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mounting the M2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Wiring the M2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 4: Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Information Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4 - 20 mA Signal Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Alarm Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Chapter 5: Configuration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Viewing & Changing M2 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 6: Gas Type Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Selecting the Gas Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Chapter 7: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Calibration Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Replacing the IR LEL Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chapter 8: RS-485 Modbus Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Wiring the M2 in a Modbus System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Using the M2 in a 4-wire Modbus System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Modbus Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Supported Modbus Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Appendix A: Control Button Quick Reference Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Appendix B: PLC and DCS Device Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Appendix C: Function Code 16 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
(Appendix C available from RKI Instruments, Inc. Not included in manual as normally
provided with M2 detector head.)
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1 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Chapter 1: Introduction
Overview
This chapter briefly describes the 65-2619RK-CH4-4 M2 Transmitter. This chapter also
describes the 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual (this document). Table 1
at the end of this chapter lists the specifications for the M2.
About the M2 Transmitter
The M2 transmitter is a fixed mount, continuous-monitoring detector head. All user
adjustable parameters may be accessed using push button switches. In addition,
calibration may be performed non-intrusively by use of a magnetic wand accessory which
activates magnetic switches through a window at the front face of the detector head.
The M2 displays the current gas reading on an LCD display which is visible through the
window in the cover (front face) and provides a 4 - 20 mA signal which indicates the
target gas reading for use by a gas monitoring controller, recording device, or
programmable controller. The M2 also provides an RS-485 Modbus output. Three sets of
relay contacts, two controlled by the gas alarms and one by the fail alarm, rated at 115
VAC 5 amps are available for controlling devices such as lights or horns or for controlling
higher rated relays.
Four operating modes allow you to display and change setup and calibration settings and
change the gas type. They are Calibration Mode, Configuration Mode, Gas Type Mode,
and Modbus Mode.
About this Manual
The M2 Transmitter Operator’s Manual uses the following conventions for notes, cautions,
and warnings.
NOTE: Describes additional or critical information.
CAUTION: Describes potential damage to equipment.
WARNING: Describes potential danger that can result in injury or death.
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 2
Specifications
Table 1 lists specifications for the M2.
WARNING: When using the M2, you must follow the instructions and warnings in
this manual to assure proper and safe operation of the M2 and to
minimize the risk of personal injury. Be sure to maintain and periodically
calibrate the M2 as described in this manual.
WARNING: M2 detector heads with firmware version 5.0 or later have a different
Modbus register assignment than M2s with previous versions of
firmware. If you are adding M2s with firmware version 5.0 or later to an
existing Modbus network installation, confirm what firmware version is
installed in the M2s already in the network and if necessary, take all steps
required to address the differences in Modbus register assignments. See
“Supported Modbus Functions” on page 40 for information on the current
Modbus register assignments. The firmware version is shown on the
Information Screen described on page 16.
Table 1: M2 Specifications
Target Gas/Detection Range Methane: 0 - 100% LEL, 1% LEL increments
Alarm Settings
(Alarm 1/Alarm 2) 10 %LEL/50 %LEL
Construction (housing) Explosion-proof Junction Box, NEMA 4
Area Classification Explosion-proof for Class I, Groups B, C, and D
Sampling Method Diffusion
Input Power 19 - 30 VDC
Controls • Three push button switches
• Three magnetic switches for non-intrusive calibration
Weight 5.5 lbs.
Signal Output • 4 to 20 mA, 500 ohms impedance max
• RS-485 Modbus
Operating Temperature -20°C to 50°C
Accuracy ± 5% of reading or ± 2% of full scale (whichever is greater)
*These are the RKI factory settings. You can change the alarm settings in Configuration Mode. See
“Viewing & Changing M2 Parameters” on page 21.
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3 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Chapter 2: Description
Overview
The M2 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 chapter describes the components of the M2 transmitter. The transmitter is a 4 - 20
mA type detector head. It consists of the combustible gas detector, calibration adapter/
splash guard, terminal PCB, the M2 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 M2 junction box can be installed in a more readily accessible
area.
External Description
This section describes the junction boxes and all external components of the M2
transmitter.
Figure 1: M2 External Components
3/4" NPT Conduit Hub Terminal
Strip
Magnetic
Wand
Detector
Junction Box
3/4" NPT Conduit Hub
Calibration Adapter/
Splash Guard
IR LEL Detector
Mounting Slot (2x)
Window
M2 Junction Box
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 4
M2 Junction Box
The M2’s cast aluminum junction box protects the terminal PCB and wiring connections
made to the terminal PCB. Use the top 3/4’’ conduit hub to connect wiring from the
terminal PCB to external power and/or to an external device, typically an RKI controller.
Use the bottom 3/4” conduit hub to wire the remotely installed IR LEL detector. Use the
junction box’s two mounting slots to mount the M2 to a vertical surface at the monitoring
site. The window in the cover on the front of the junction box allows you to view the LCD
display and use the magnetic wand to actuate the magnetic control switches so you can
perform non-intrusive calibration. Removing the cover allows you to access the interior of
the junction box.
Detector Junction Box
The detector junction box is intended to be installed remotely from the M2 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 M2 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.
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 terminal strip.
Calibration Adapter/Splash Guard
A calibration adapter/splash guard is installed on the IR LEL detector. A fitting at the
bottom of the calibration adapter/splash guard allows a length of tubing to be connected
for calibration and routed to a more easily accessible location (near the M2 junction box is
optimal for ease of calibration). The calibration adapter/splash guard also protects the
detector from splashing water or direct water spray.
Magnetic Wand
The magnetic wand is a short plastic rod with a magnet in one end. It is used to actuate
the magnetic control switches on the control PCB while the junction box cover is still
installed so that non-intrusive calibration can be performed.
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5 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Internal Description
This section describes the internal components of the M2. The internal components of the
M2 include the terminal PCB which provides for all the wiring connections to the M2 and
the control PCB which displays the gas reading and has the control buttons.
Figure 2: M2 Internal Components
Terminal PCB
The terminal PCB is encapsulated in epoxy for protection against moisture and physical
damage. It is mounted into the rear of the junction box with three standoffs and rests on a
thin layer of foam. A banana jack is screwed into each of the standoffs and used for
mounting the control PCB. The terminal PCB converts the electrical output from the
detector to a signal which can be displayed by the LCD display, a 4 - 20 mA signal (that is
proportional to the detection range), and an RS-485 Modbus output signal. The 4 - 20 mA
signal may be used by a recording device, gas monitor controller, or programmable
controller. The Modbus output may be used to connect the M2 to a Modbus network. The
terminal PCB also controls three relays, one fail and two gas alarm relays.
Two columns of plug-in style terminal strips are used to make all wiring connections to
the M2. The column on the left consists of the power/signal, detector, and Modbus
terminal strips. The column on the right consists of the relay terminal strips. A 20 position
connector at the bottom of the terminal PCB is used to connect the terminal PCB to the
Alarm 1 LED
Fail LED
TX LED
RX LED
Alarm 2 LED
UP/YES
ENTER
LCD Display
ENTER
DOWN/NO
Push Button
Control Switches
C NC NO
ALARM 1
LEL
R W G B
R W G B
FAIL
C NC NO
PWR/SIG
- S +
- S +
Detector Terminal Strip
Power/Signal
Terminal Strip
Programming
Connector
(Factory Use)
Detector
Current Pot
(Factory
Adjust)
UP/YES
DOWN/NO
Termination
Jumper
View With Cover Removed
Modbus
Terminal Strip
View With Cover and
Control PCB Removed
Display
Ribbon Cable
Connector
3/4" NPT Conduit Opening
for Wire Entry
LEL PWR/SIG
RKI INSTRUMENTS
M2 TRANSMITTER
A B C
R S 485
A B C
RS485
ALARM 2
C NC NO
Relay
Terminal
Strips
Junction Box
Magnetic
Switches
Terminal PCB
Control PCB
3/4" NPT Conduit
Opening for
Detector J-Box
Wiring
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 6
control PCB with a ribbon cable. A 5 position connector on the left side of the terminal
PCB is used by factory or field service personnel to program the M2. A factory adjust pot
just above the programming connector is used to set the detector current.
Power/Signal Terminal Strip
The power/signal terminal strip is a three position plug-in style terminal strip located at
the top of the left terminal column. It is used to connect 24 VDC power to the M2 and to
connect the 4 - 20 mA output signal to a device.
The signal output, the S terminal, does not have to be connected for the M2 to function.
The S terminal is used if you want to connect the 4 - 20 mA output signal to another device
such as a gas monitoring controller, chart recorder, or programmable controller (PLC).
Detector Terminal Strip
The detector terminal strip is a four position plug-in style terminal strip and is the middle
terminal strip in the left terminal column. All four terminals are used to connect the
detector to the M2.
Figure 3: Detector Terminal Strip
NOTE: The detector is factory-wired to the M2. See “Wiring the M2 Transmitter” on
page 11 for all wiring procedures related to M2.
Modbus Terminal Strip
The Modbus terminal strip is a three position plug-in style terminal strip and is the
bottom terminal strip in the left terminal column. It allows connection of the M2 into a
Modbus network.
Relay Terminal Strips
The right column of terminal strips consists of, from top to bottom, the fail, alarm 1, and
alarm 2 relay terminal strips. They are three-position plug-in style terminal strips. The
relay terminal strips are used to connect devices such as lights and horns that are
controlled by the relay contacts. The relay contacts are rated at 115 VAC, 5 amps. The relay
contacts may also be used to control higher rated relays.
FAIL
- S +
PWR/SIG
C NC NO
A B C
ALARM 2
RS485
PWR/SIG
- S +
LEL
Detector
Terminal Strip
RS485
A B C
R W G B
C NC NO
LEL
ALARM 1
C NC NO
R W G B
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7 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Termination Jumper
A two pin header with a termination jumper installed is located below the Modbus
terminal strip. The jumper has no function unless the M2 is wired into a Modbus
installation. See “Chapter 8: RS-485 Modbus Output” on page 35 for a description of using
the M2 in a Modbus system.
Control PCB
The LCD display and control switches are located on the control PCB. It is installed on top
of the terminal PCB by lining up its three spacing standoffs with the banana jacks in the
terminal PCB mounting standoffs and pushing it onto the banana jacks. The jacks retain
the control PCB.
LCD Display
The LCD display is located at the top of the control PCB. It indicates the current gas
reading and displays messages and parameters in the M2’s programs.
Control Buttons
The M2 includes three push button switches that allow you to enter the M2’s operating
modes, navigate through the modes, update settings, and save changes to the settings.
The push button switches are located along the bottom edge of the control PCB (see
Figure 2). The UP/YES button is on the left, the DOWN/NO button is in the middle, and
the ENTER button is on the right.
Just above each push button switch is a magnetic switch with the same function as the
push button switch below it. The magnetic switches are for use in non-intrusive
calibration. They are actuated by bringing the magnetic wand close enough to them to
actuate them. Although the magnetic switches have the same functions as the push button
switches, it is not practical to use them for operations other than calibration because it is
not possible to actuate two magnetic switches at once with only one magnetic wand. Since
displaying the Information Screen only requires the use of one switch, the wand may be
used to show the Information Screen (see “Information Screen” on page 16).
Table 2: M2 Control Button Functions
Switch Function
UP (YES) • Saves settings
• Changes the displayed setting
• Enters the Calibration Program
• Enters Gas Type Mode (press with DOWN/NO button)
• Enters Configuration Mode (press with ENTER button)
DOWN (NO) • Cancels setting changes
• Changes the displayed setting
• Enters Gas Type Mode (press with UP/YES button)
• Enters Modbus Mode (press with ENTER button)
• Displays the Information Screen
ENTER • Initiates operations
• Enters Configuration Mode (press with UP/YES button)
• Enters Modbus Mode (press with DOWN/NO button)
• Functions as an alarm reset switch
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 8
Status LEDs
The M2 includes five status LEDs that are located above the display (see Figure 2).
• Fail LED
The fail LED turns on when the M2 is experiencing a fail condition. A fail condition
can be caused by a detector failure or low detector signal.
• Alarm 1 LED
The alarm 1 LED is on when the M2 is experiencing an alarm 1 condition.
• Alarm 2 LED
The alarm 2 LED is on when the M2 is experiencing an alarm 2 condition.
• RX & TX LED’s
These LED’s indicate data being received (RX) and transmitted (TX) when the M2’s
Modbus output is operating.
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9 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Chapter 3: Installation & Startup
Overview
This chapter describes procedures to mount the M2 Transmitter in the monitoring
environment and wire it to input power and devices.
Mounting the M2 Transmitter
1. Select a mounting site that is representative of the monitoring environment. Consider
the following when you select the mounting site.
• For the M2 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.
2. Use #10 screws through the M2 junction box’s two mounting slots to secure the
junction box to a vertical surface. Figure 4 shows the outline and mounting
dimensions the M2 junction box. Figure 5 shows the outline and mounting
dimensions for the detector junction box. Mount the detector junction box with the
detector facing down as shown in Figure 5.
Figure 4: Outline & Mounting Dimensions, M2 Junction Box
.30 (2X)
3/4 NPT
Conduit Hub
5.23
.47 (2X)
2.41
5.00
1.02
5.86
4.59
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 10
Figure 5: Outline & Mounting Dimensions, Detector Junction Box
3. Install 3/16 inch I.D. flexible polyurethane tubing to the fitting at the bottom of the
calibration adapter/splash guard and route it to an accessible area that is close to the
M2 junction box. See the “Parts List” on page 45 for available tubing.
.382.70
Rubber
Spacer,
3X
J-Box
.75
3/4 NPT
Female
3.65
IR LEL
Detector
9.00 MAX
Calibration
Adapter/
Splash Guard
5.25
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11 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Wiring the M2 Transmitter
WARNING: Always verify that the power to the M2 is off before you make wiring
connections.
1. Confirm that no power is being applied to the M2.
2. Remove the detector junction box’s cover from the junction box.
3. Remove the M2 junction box’s cover from the junction box.
4. Grasp the control PCB by its edges.
5. Gently pull until the control PCB is pulled away from the banana jacks. Take care not
to pull too hard and damage the cable which connects the control and terminal PCBs.
6. Let the control PCB hang by the cable. The terminal strips are now visible on the
terminal PCB. The control PCB may be left hanging while wiring is done. If desired,
the control PCB may be disconnected from the cable and set aside while wiring.
7. 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.
8. Connect the detector leads to the terminal block in the detector junction box.
9. Secure the detector junction box’s cover to the junction box.
10. Guide the other end of the four-conductor, shielded cable or four wires in conduit
through the bottom conduit hub of the M2 junction box.
11. To gain access to a plug-in terminal strip for wiring, pull it out of its socket by
grasping the wall between two terminal positions with needle nose pliers and pulling.
Be careful not to exert too much force on the wall to avoid damage to the terminal
strip. The detector terminal strip and the alarm 1 relay terminal strip may be removed
by grasping them with your fingers if the adjacent terminal strips have been removed.
WARNING: If the M2 is installed in a hazardous location, use appropriately rated
conduit, conduit fittings, and appropriate construction technique that
complies with the local electrical code.
In addition, use appropriately rated conduit, conduit fittings, and
appropriate construction technique to maintain the NEMA 4
environmental rating of the junction box and avoid water entering the
junction box at the conduit hubs.
12. Pull out the detector terminal strip and connect the four wires to the terminal strip as
follows (see Figure 6).
• 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.
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 12
• 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 M2 junction box’s chassis (earth) ground.
Figure 6: Wiring the Detector to the M2
13. Reinstall the detector terminal strip into its socket.
14. If shielded cable is used between the detector junction box and the M2 junction box,
connect the cable’s drain wire to an available chassis (earth) ground at the M2 junction
box. Do not connect the shield drain wire at the detector junction box.
15. Guide multi conductor shielded cable or cables or wires in conduit through the top
conduit hub of the M2 junction box. The number of cables or wires needed will
depend on whether the M2 is wired to a gas monitoring controller or just to power,
whether any relays are used, and whether the Modbus output is used.
NOTE: If the M2 is being wired to a PLC or DCS device, see “Appendix B: PLC and
DCS Device Wiring” on page 47, then continue with step 8.
Red
White
Green
Black
C NC NO
IR LEL Detector
Detector J-Box
ALARM2 ALARM1
C NC NO C NC NO
FAIL
- S +
LEL
R W G B
- S +
PWR/SIGRS 485
R W G B
Detector
Terminal
Strip
LEL PWR/SIGRS 485
A B C
A B C
Calibration Adapter/Splash Guard
Black
Green
White
Red
Cable
Shield
M2
J-Box
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13 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
Use the following recommendations to determine how to wire the M2:
• If Modbus connections will not be used and only the PWR/SIG connections will
be used, use a two or three conductor shielded cable or two or three wires in
conduit for connections to the power/signal terminal strip depending on whether
or not the signal (S) terminal is used. The S terminal has a 4 - 20 mA output, but if
you do not need to monitor this signal and do not connect to the S terminal to
access this signal, the M2 will still function completely.
• If the PWR/SIG connections and one or more relays are used, route the
connections to the M2 in conduit. Use shielded cable in the conduit for the PWR/
SIG connections and unshielded cable or individual wires for the relay
connections. Make sure any wire or cable used for relay wiring is appropriately
rated for the power that it will carry.
CAUTION: If shielded cable is used for the PWR/SIG connections, leave the cable shield’s drain
wire insulated and disconnected at the M2 junction box. You will connect the
opposite end of the cable’s drain wire at the controller or device.
• If the M2 will be wired into a Modbus network, see “Chapter 8: RS-485 Modbus
Output” on page 35.
See Figure 7 below for field wiring connections to the M2.
Figure 7: Wiring the M2 Junction Box to a Controller and Alarm Devices
Table 3: Wire Size for PWR/SIG Connections
Max Distance to Controller
w/18 Gauge Wire Max Distance to Controller w/16 Gauge Wire Max Distance toController w/14 Gauge Wire
2,500 ft. 5,000 ft. 8,000 ft.
LEL
FAIL
C NC NO
PWR/SIG
S
Fail
Alarm
Device
Alarm 1
Alarm
Device
ALARM 2
Alarm Device
Power
RS 485
A B C
Typical Alarm
Wiring Shown
Alarm 2
Alarm
Device
RKI Controller
Terminals
(24 VDC) +
4-20mAIn(S)
(24 VDC) -
Cable Shield
See
Detector
Wiring
See
Modbus
Wiring
R W G B
ALARM 1
C NC NO
C NC NO
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65-2619RK-CH4-4 M2 Transmitter Operator’s Manual 14
16. Re-install the control PCB (and ribbon cable if necessary). Be sure the ribbon cable is
routed down below the control PCB so it will not be damaged by the cover when it is
screwed back on.
17. Secure the M2 junction box cover to the junction box.
18. Make controller, device, and relay connections as appropriate. If shielded cable is
used for the PWR/SIG connections, connect the cable shield’s drain wire to an
available chassis ground at the gas monitoring controller, recording device, or
programmable controller.
Start Up
Introducing Incoming Power
1. Complete the installation procedures described earlier in this manual.
2. Verify that all wiring connections are correct and secure.
3. Turn on the incoming power.
4. If necessary, turn on the controller or other monitoring device that is connected to the
M2.
5. The LCD display will indicate the firmware version when the M2 is first powered up
and will then count down a one minute warm-up period before normal operation
begins. During normal operation, the display will indicate the target gas and current
gas reading. Verify that the display is indicating the target gas and current gas reading
after the warm-up period is complete and normal operation begins.
NOTE: Allow the M2’s detector to warm up for 15 minutes before you continue with
the next section, “Adjusting the Fresh Air Reading.”
Adjusting the Fresh Air Reading
When the M2 is shipped from RKI Instruments, Inc., it is factory calibrated. If a full
calibration is desired at startup, see “Calibration” on page 31.
Verify that the M2 is in a fresh air environment (environment known to be free of
combustible or toxic gas vapors and of normal oxygen content, 20.9%).
CAUTION: If you suspect the presence of combustible gas in the monitoring environment, use
the calibration kit and the zero air calibration cylinder to introduce “fresh air” to
the detector and verify an accurate fresh air setting. See the “Calibration” on
page 31 for instructions on how to use a zero air cylinder when performing a fresh
air adjustment.
Non-Intrusive Fresh Air Signal Adjustment
If the M2 is installed in a classified area and non-intrusive zero adjustment is required,
follow the instructions below, but do not remove the junction box cover. Use the
magnetic wand accessory to actuate the magnetic switches instead of pushing the control
switch buttons. To actuate a magnetic switch and perform the same operation as pressing
METHANE
0 %LEL
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15 65-2619RK-CH4-4 M2 Transmitter Operator’s Manual
a control switch button, touch the magnet in the end of the magnetic wand to the M2’s
glass cover directly over the magnetic switch you wish to actuate. Touching the glass and
removing the wand is the same as pressing and releasing a button. Touching the glass and
keeping the wand in place is the same as pressing and holding a button.
WARNING: The M2 is not an active gas monitoring device during the fresh air
adjustment procedure. The 4-20 mA output signal will “freeze” at 3.5 mA
and all relays will remain in their non-alarm state while the M2 is in
Calibration Mode. The output signal will not indicate current readings
and the relays will not resume operating normally until the M2 is in
normal operation again.
NOTE: While in the calibration program, if there is no switch activity for the
calibration time-out period the unit will return to normal operation. The factory
set time-out is 15 minutes. If you want a different time-out period, see
“Viewing & Changing M2 Parameters” on page 21 for instructions to change
the calibration time-out.
1. While in normal operation, press and hold the UP/YES button for 5 seconds to enter
Calibration Mode. Release the button when the following screen appears.
2. Press and release the UP/YES button to continue. The display will indicate the target
gas and CAL Mode for a few seconds before showing FreshAir Adjust?.
3. Press and release the UP/YES button. ENTER will alternate with FreshAir on the top
display line and the current gas reading will be on the bottom display line.
4. Press and release the ENTER button. The M2 will perform a zero operation and the
display will indicate SPAN w/Cal Gas?.
5. Press and release the DOWN/NO button. The display will indicate Leaving CAL
Mode and the M2 will return to normal operation.
Calib?
YES/NO
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