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18

65-2645RK-05-04 M2A Transmitter Operator’s Manual

14. Pull out the detector terminal strip and connect the two wires to the terminal strip as follows (see Figure 8).

Connect the wire corresponding to the detector’s red wire to the 

TOXIC “+”

 terminal.

Connect the wire corresponding to the detector’s black wire to the 

TOXIC “-”

 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 M2A 
junction box’s chassis (earth) ground.  

Figure 8: Wiring the Detector to the M2A

15. Reinstall the detector terminal strip into its socket.

16. If shielded cable is used between the detector junction box and the M2A junction box, connect the cable’s 

drain wire to an available chassis (earth) ground at the M2A junction box. Do not connect the shield drain 
wire at the detector junction box.

Cable

Shield

Red

Blac k

C  

 N

C

  

 NO

 

AL

AR

M

 1

C  

 NC

   

NO

 

AL

AR

M

 2

C  

 N

C

  

 NO

 

FA

IL

   

 S

   

   

+

 

PW

R

/S

IG

T

O

X

IC

  

  

  

  

O

X

Y

+  

  

  

 

 

Detector

Term inal

Strip

+  

  

  

 

 

Blac k

M 2A
J-Box

Detector J -B ox

Calibration A dapter/S plash Guard

Install c onduit seal

within 2 i nches

H2S Detector

Install c onduit seal within

2 i nches ( for G roup B  

env ironm ents) or 18 

inches ( for G roups C and

D e nv ironm ents)

Red

A

  

   

B

  

  

 C

 

RS

 4

8

5

Summary of Contents for 65-2645RK-05-04

Page 1: ...RKI Instruments Inc www rkiinstruments com 65 2645RK 05 04 M2A Transmitter Operator s Manual Part Number 71 0348 Revision F Released 9 9 20...

Page 2: ...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...

Page 3: ...r 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 REPRESENTA...

Page 4: ...8 Internal Description 11 Chapter 3 Installation Startup 15 Overview 15 Mounting the M2A Transmitter 15 Wiring the M2A Transmitter 17 Start Up 20 Chapter 4 Operation 22 Overview 22 Normal Operation 2...

Page 5: ...Replacing Components of the H2S Detector 37 Chapter 8 RS 485 Modbus Output 40 Overview 40 Wiring the M2A in a Modbus System 40 Using the M2A in a 4 wire Modbus System 43 Modbus Mode 43 Supported Modb...

Page 6: ...ch 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 co...

Page 7: ...tings Alarm 1 Alarm 2 10 ppm 50 ppm Construction housing Explosion proof junction box NEMA 4X Area Classification Explosion proof for Class I Groups B C and D Sampling Method Diffusion Input Power 10...

Page 8: ...ons where the detector needs to be installed at an inaccessible location The detector junction box can be installed at the inaccessible location and the M2A junction box can be installed in a more rea...

Page 9: ...he 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 Th...

Page 10: ...o access the plug in sensor for maintenance or replacement A cap gasket seals the interface between the housing and cap A flame arrestor guard is permanently bonded to the cap Rubber Boot and Spacer A...

Page 11: ...A 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 Modbu...

Page 12: ...e M2A NOTE The detector is factory wired to the M2A See Wiring the M2A Transmitter on page 17 for all wiring procedures related to M2A Modbus Terminal Strip The Modbus terminal strip is a three positi...

Page 13: ...rminal 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 Figure 5 Control...

Page 14: ...e 5 Fail LED The fail LED turns on when the M2A 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...

Page 15: ...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 gas...

Page 16: ...ible 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 M2A junction box See the Chapter 9 Parts List on p...

Page 17: ...te construction technique 9 Guide a two conductor shielded cable or two wires in conduit through the top conduit hub of the detector junction box To make wiring more convenient use wire colors that co...

Page 18: ...s chassis earth ground Figure 8 Wiring the Detector to the M2A 15 Reinstall the detector terminal strip into its socket 16 If shielded cable is used between the detector junction box and the M2A junc...

Page 19: ...to prevent water from entering through the top port NOTE If the M2A is being wired to a PLC or DCS device see Appendix B PLC and DCS Device Wiring on page 52 then continue with step 8 Use the followin...

Page 20: ...tions 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 M2A 5 The OLED display will indicate the firmware ve...

Page 21: ...asing a button Touching the glass and keeping the wand in place is the same as pressing and holding a button WARNING The M2A is not an active gas monitoring device during the fresh air adjustment proc...

Page 22: ...Continue holding the DOWN NO button to keep the Information Screen on the display The top line indicates the operating voltage that is connected to the M2A The second line indicates the firmware that...

Page 23: ...5 mA Alarm Indications NOTE The M2A includes alarm on and alarm off delay settings for alarm 1 and alarm 2 The alarm indications described in this section operate according to the factory set alarm se...

Page 24: ...falls below the alarm 1 setpoint Alarm 2 Condition Alarm 2 Condition Indications When the gas reading reaches the alarm 2 setpoint the M2A senses an alarm 2 condition The M2A alerts you to an alarm 2...

Page 25: ...olts or less WARNING While in a low power condition the M2A is not an active gas monitor When the M2A senses a low power condition it alerts you as follows The F LED turns on The message LowPower is i...

Page 26: ...uttons when the following screen appears 2 If you want to exit Configuration Mode press and release the DOWN NO button and the M2A will return to normal operation If you want to continue in Configurat...

Page 27: ...ng at which the M2A initiates an alarm 2 condition ALARM 2 activation Increase Indicates if the alarm 2 circuit is activated by gas readings increasing Increase or decreasing Decrease to the ALARM 1 L...

Page 28: ...zero suppression is 2 0 ppm the M2A will display a reading of 0 ppm for gas readings from 2 ppm to 2 ppm It is settable from 0 to 6 of the detection range FILTER 5 secs The filter feature helps smooth...

Page 29: ...turned on Selecting the Gas Type 1 While in normal operation or during the warm up sequence press and hold the UP YES and DOWN NO buttons for five seconds Release them when the following screen appear...

Page 30: ...d move to the next one Use the UP YES and DOWN NO buttons to adjust a setting See Chapter 5 Configuration Mode on page 26 for a complete description of Configuration Mode 7 When you have reviewed and...

Page 31: ...button for 5 seconds to enter Calibration Mode but since a calibration is required only a momentary push is needed to enter Calibration Mode after changing the gas type 11 See Calibration on page 35...

Page 32: ...probable causes and recommended action for problems you may encounter with the M2A NOTE This troubleshooting guide describes M2A problems only If the M2A is connected to a controller see the controlle...

Page 33: ...ed See Wiring the M2A Transmitter on page 17 2 Verify that the detector wiring is correct and secure 3 Increase the filter setting in Configuration Mode 4 Increase the zero suppression setting in Conf...

Page 34: ...or this operation 4 Use the flexible tubing coming from the calibration adapter splash guard to connect the regulator to the calibration adapter splash guard 5 Turn the regulator s on off knob counter...

Page 35: ...lowing procedure assumes the use of a calibration kit which includes a calibration gas cylinder a zero air cylinder and a fixed flow regulator with an on off knob NOTE The detector must be calibrated...

Page 36: ...lease 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 To skip adjusting the fresh air reading press and rele...

Page 37: ...ation screen and the message REMOVE CAL GAS for 1 minute If the calibration gas has not been removed from the detector remove it now to avoid unwanted alarms During this 1 minute period the signal out...

Page 38: ...up for 5 minutes before you continue with the next step 12 Calibrate the transmitter as described in the Calibration on page 35 Replacing the H2S Detector NOTE In most cases it is only necessary to re...

Page 39: ...M2A Transmitter Operator s Manual 39 CAUTION Allow the replacement detector to warm up for 5 minutes before you continue with the next step 11 Calibrate the replacement detector as described in Calibr...

Page 40: ...to be connected together RS 485 repeater s should be used such that no more than 128 M2As reside on any given network segment CAUTION The network segment can only support 128 units if RKI M2As are be...

Page 41: ...e This should only be done if wiring for a system that is being replaced is already installed and it is not practical to run another wire See Figure 12 below for this wiring configuration In this conf...

Page 42: ...in an M2A that is at the end of a Modbus line Any M2A in a Modbus system that is not at the end of a line must have the termination jumper removed see Figure 13 Figure 14 below Figure 13 Multiple M2As...

Page 43: ...atically returns to normal operation NOTE If the M2A returns to normal operation because of a time out it enters a warm up period just as it does when it is first turned on 1 While in normal operation...

Page 44: ...normal operation NOTE All M2As on a Modbus network must be configured with the same baud rate and parity and each M2A must have a unique slave ID For an M2A to participate on a network the ENABLED DI...

Page 45: ...Reading with Sign Decimal Point Bit Field Assignments Bit s Value Field 15 Sign of Reading 0 Positive 1 Negative 14 13 Format of Reading 0 XXX no decimal point 1 XX X 2 X XX 3 XXX 12 0 Numerical value...

Page 46: ...1 Register 14 Register 14 is the alarm 2 set point The decimal point location is the same as specified in Register 1 8 Fail Status 0 Fail Not Asserted 1 Fail Asserted 7 6 Alarm 2 Status 0 No Alarm 1...

Page 47: ...rm 1 relay reset 0 Latching 1 Self Resetting Register 26 Register 26 is the alarm 1 ON delay Integer values are in seconds Register 27 Register 27 is the alarm 1 OFF delay Integer values are in second...

Page 48: ...y 0 and the 1st 0 Register 37 Register 37 is the calibration year Register 38 Register 38 is the calibration outcome Upper Gas Operation Lower Air Operation Calibration Outcome Codes 1 Sensor Missing...

Page 49: ...unction Code 16 see Appendix C Function Code 16 Registers on page 54 Register 16 Register 16 performs the same function as the ENTER button on the M2A It is useful for remotely silencing alarms With t...

Page 50: ...ector assembly includes sensor CSA version 71 0348 65 2645RK 05 04 M2A Transmitter Operator s Manual this document 81 0076RK 01 Zero air calibration cylinder 34 liter steel 81 0076RK 03 Zero air calib...

Page 51: ...Button Quick Reference Chart Mode Entered or Function Performed Button Combination Adjustable or Viewable Parameters Alarm Reset Press and Release ENTER n a Show Information Screen Press and Hold DOW...

Page 52: ...he PWR SIG terminal strip connections and one or more relays are used route the connections to the M2A in conduit Use shielded cable in the conduit for the PWR SIG connections and unshielded cable or...

Page 53: ...PLC and DCS Device Wiring S PWR SIG Alarm 1 Alarm Device Fail Alarm Device Alarm Device Power Typical Alarm Wiring Shown A B C RS 485 4 20 mA In S 24 VDC 24 VDC 24 VDC Power Supply 24 VDC Alarm 2 Ala...

Page 54: ...0 Normally De Energized 1 Normally Energized Register 4 Register 4 is the alarm 1 relay reset 0 Latching 1 Self Resetting Register 5 Register 5 is the alarm 1 ON delay Integer value is in seconds Regi...

Page 55: ...5 second increments Register 15 Register 15 is the calibration timeout Value is in minutes 5 10 15 20 25 or 30 Register 16 Register 16 is explained in Supported Modbus Functions in the M2A manual Reg...

Page 56: ...2A Transmitter Operator s Manual Register 20 Register 20 is the AutoZero Disable 0 AutoZero Enabled 1 AutoZero Disabled Register 21 Register 21 is the Remote Configuration Register 0 No Remote Configu...

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