Summary of Contents for RKI Instruments 65-2645RK-05-04
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65-2645RK-05-04 M2A Transmitter Operator’s Manual Part Number: 71-0348 Revision: F Released: 9/9/20 RKI Instruments, Inc. www.rkiinstruments.com...
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Typical calibration frequencies for most applications are between 3 and 6 months, but can be required more often or less often based on your usage. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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.
Chapter 1: Introduction Overview This chapter briefly describes the 65-2645RK-05-04 M2A Transmitter. This chapter also describes the 65- 2645RK-05-04 M2A Transmitter Operator’s Manual (this document). Table 1 at the end of this chapter lists the specifications for the M2A. About the M2A Transmitter The M2A transmitter is a fixed mount, continuous-monitoring detector head.
When using the M2A, you must follow the instructions and warnings in this manual to assure proper and safe operation of the M2A and to minimize the risk of personal injury. Be sure to maintain and periodically calibrate the M2A as described in this manual. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
3/4 NPT Conduit Hub Term inal Strip Magnetic W and W indow 3/4 NPT Conduit Hub Junction Detector Junction Box Hydrogen Sulfide 3/4 NPT Detector Conduit Hub Calibration Adapter/ Splash Guard Figure 1: M2A External Components 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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S detector consists of the detector housing body, detector housing cap, cap gasket, rubber boot, spacer, and the plug-in sensor. Detector Housing Body Cap Gasket H2S Plug-in Sensor Spacer Rubber Boot Detector Housing Cap Flame Arrestor Guard Figure 2: H S Detector Component Location 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
A 20 position connector at the bottom of the terminal PCB is used to connect the terminal PCB to the 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 M2A. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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The push button switches are located along the bottom edge of the control PCB (see Figure 5). The UP/YES button is on the left, the DOWN/NO button is in the middle, and the ENTER button is on the right. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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The alarm 2 LED is on when the M2A is experiencing an alarm 2 condition. • RX & TX LED’s These LED’s indicate data being received (RX) and transmitted (TX) when the M2A’s Modbus output is operating. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
Mount the detector junction box with the detector facing down as shown in Figure 7. 4.59 5.00 3/4 NPT 2.41 Conduit Hub, 5.86 5.23 1.02 .30 (2X) .47 (2X) Figure 6: Outline & Mounting Dimensions, M2A Junction Box 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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 M2A junction box. See the “Chapter 9: Parts List” on page 50 for available tubing. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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• If the M2A will be wired into a Modbus network, see “Chapter 8: RS-485 Modbus Output” on page 40. See Figure 9 below for field wiring connections to the M2A. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
0 ppm NOTE: Allow the M2A’s detector to warm up for 15 minutes before you continue with the next section, “Adjusting the Fresh Air Reading.” 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Adjusting the Fresh Air Reading When the M2A is shipped from RKI Instruments, Inc., it is factory calibrated. If a full calibration is desired at startup, see “Calibration” on page 35. Verify that the M2A is in a fresh air environment (environment known to be free of combustible or toxic gas vapors and of normal oxygen content, 20.9%).
There are several circumstances where the signal output will not track the display reading but will behave as follows: • When the M2A is in its warm-up period, the signal output will be fixed at 3.5 mA (zero). 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
You can select normally energized (N. EN) or normally de-energized (N. DE-EN) alarm 1 and alarm 2 relay settings in Configuration Mode. The following sections describe the standard factory setting for these relays which is N. DE-EN. The fail relay is factory set as N. EN and is not user-adjustable. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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If the ENTER button is pressed while the M2A is in an alarm 2 condition, the A2 LED will flash but all other indications will remain unchanged. You cannot de-energize the alarm 2 relay until the gas reading falls below the alarm 2 setpoint. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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When the input power increases above 10.0 volts, the M2A will begin its warm-up sequence. Verify that the M2A enters normal operation after its warm-up sequence. If necessary, perform a fresh air adjustment. See “Adjusting the Fresh Air Reading” on page 21. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
The gas reading at which the M2A initiates an alarm 1 condition. (10 ppm) ALARM-1 (activation) Indicates if the alarm 1 circuit is activated by gas readings increasing (Increase) (Increase) or decreasing (Decrease) to the ALARM-1 Level. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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SELF-RST. It can be set in 1 second increments from 0 - 60 seconds, in 1 minute increments from 1 - 15 minutes, and in 15 minute increments from 15 - 60 minutes. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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M2A will return to the first adjustable parameter. Go back to step 3 and continue. If you wish to save the adjustments made, press and release the UP/YES button. Config Saved is indicated on the display for a few seconds and the M2A returns to normal operation. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
The target gas is factory set and does not normally need to be changed. The standard setting for the 65-2645RK-05-04 is hydrogen sulfide. Gas Type Mode includes a 5-minute time-out feature. If you do not press a button for 5 minutes, the M2A automatically returns to normal operation.
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OVER? YES/NO. Press the UP/YES button and the display will indicate Re-do Config, then display the target gas and the detection range for a few seconds before returning to Configuration Mode. Repeat steps 6 - 8 until the settings are as desired. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Since a complete calibration is required, the calibration sequence will proceed without asking if you want to perform certain operations. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
PCB is securely installed. This ribbon cable plugs into a connector on the top edge of the control PCB and on the bottom of the terminal PCB. 3. If the power difficulties continue, contact RKI for further instruction. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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The detector fresh air 5. If the fail condition continues, signal is low enough contact RKI for further instruction. to cause a fail condition. • The detector is malfunctioning. • The terminal or display PCB is malfunctioning. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
Although there is no particular calibration frequency that is correct for all applications, a calibration frequency of every 3 to 6 months is adequate for most hydrogen sulfide transmitter applications. Unless experience in a particular application dictates otherwise, RKI Instruments, Inc. recommends a calibration frequency of every 3 months.
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. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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If you want to skip adjusting the span reading, press and release the DOWN/NO button. The display will indicate Leaving Cal Mode and the M2A will return to normal operation. It is important to vent the regulator while installing it onto the cylinder. Venting the regulator during 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
Turn off or unplug power to the M2A. Unscrew the calibration adapter/splash guard from the detector housing cap. Unscrew the detector housing cap from the detector housing body. Make sure not to lose the cap gasket. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Connect the detector leads to the terminal block the same way the old detector was wired (see Figure 8 on page 18). Screw the calibration adapter/splash guard onto the new detector housing cap. Reinstall the detector junction box cover. 10. Turn on or plug in power to the M2A. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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 “Calibration” on page 35. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
M2A isn’t wired into a Modbus system or if it is wired into one as shown in Figure 12, the ground jumper should be installed. If the M2A is wired in a Modbus system as shown in Figure 11, the ground jumper should be removed. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Modbus controller is connected to the “-” of the 24 VDC power supply. The ground jumper must be installed in this wiring configuration. Power Supply 10-30 VDC Detector Detector Additional Wiring Wiring M2As Common Input Terminals Modbus Controller Figure 12: Alternate Modbus Wiring 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Not Installed Not Installed ID = 2 ID = 3 ID = 4 ID = 127 Up to 128 M2As can be connected without a repeater Figure 14: Multiple M2As in a Two Branch Configuration 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
If the currently displayed parameter setting is OK, press the ENTER button to proceed to the next parameter. Table 9 lists the M2A Modbus Mode parameters you can set. Table 9 also lists the factory set value for each parameter. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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/ DISABLED setting must be set to ENABLE. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
5 = Calibration 6 = Post-Calibration 7 = Low Power 8 = Setup [11] Gas Type Change 0=Not Changed 1=Changed [10] Configuration Change 0=Not Changed 1=Changed Calibration Activity Flag 0=No Calibration Activity 1=Calibration Activity Has Occurred 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Register 13 is the alarm 1 set point. The decimal point location is the same as specified in Register 1. Register 14 Register 14 is the alarm 2 set point. The decimal point location is the same as specified in Register 1. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Register 30 is the alarm 2 relay reset. 0=Latching 1=Self-Resetting Register 31 Register 31 is the alarm 2 ON delay. Integer values are in seconds. Register 32 Register 32 is the alarm 2 OFF delay. Integer values are in seconds. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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12=LEL Sensor Offset Is Too High 13=LEL Null Operation Failed 14=Operation Not Performed Register 39 Register 39 is the auto-zero disable. 0=AutoZero Enabled 1=AutoZero Disabled Register 40 Register 40 is the remote configuration register access level 0=None 1=Alarm Reset 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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Table 12: Register 16, Button Function NOTE: Register 40 in Function Code 03, the remote configuration register, must be set to 1 in order for Register 16 to work. Value & Field ENTER (used for “Alarm Reset”) 0=Not Pressed 1=Pressed 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
Gas Type UP/YES and DOWN/NO for 5 seconds Modbus Mode Press and Hold • Enable or Disable Modbus DOWN/NO and • Slave ID ENTER for 5 • Baud Rate seconds • Parity • Response Delay 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
M2A. You will connect the opposite end of the cable’s drain wire at the controller or device. • If the M2A will be wired into a Modbus network, see “Chapter 8: RS-485 Modbus Output” on page 40. 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
The decimal point location is the same as specified in Register 1 of Function Code 03. Register 8 Register 8 is the alarm 2 trigger. 0=Decreasing 1=Increasing Register 9 Register 9 is the alarm 2 relay state. 0=Normally De-Energized 1=Normally Energized 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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This register can be used to clear those flags. Table 16: Register 19, Clear Change Flags Bit(s) Value & Field [15:2] Unused Write “1” to this bit to clear “Gas Type Changed” flag Write “1” to this bit to clear “Configuration Changed” flag 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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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 Configuration 1=Reset Alarm 65-2645RK-05-04 M2A Transmitter Operator’s Manual...
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