detcon inc. Detcon MicroSafe™ IR-622 Combustible Hydrocarbon Sensor (0-100% LEL) Operator’s Installation & Instruction Manual November 26, 2007 • Document #2195 • Version 6.3 CAUTION: Before operating the Model IR-622 sensor, read this manual thoroughly and verify that the configuration of default factory settings are appropriate and correct for your application. The settings include: relay contact outputs (section 3.5.5d), alarm settings (section 3.5.5e and 3.9), and RS-485 ID (section 3.5.5f and 3.12).
Table of Contents 3.0 Description 3.1 Principle of Operation 3.2 Application 3.3 Specifications 3.4 Operating Software 3.5 Installation 3.6 Start-up 3.7 Calibration 3.8 Status of Programming, Alarms, Calibration Level, RS-485 ID, and Sensor Life 3.9 Programming Alarms 3.10 Program Features 3.11 RS-485 Protocol 3.12 Display Contrast Adjust 3.13 Optical Sensor Replacement 3.14 Troubleshooting 3.15 Spare Parts List 3.16 Warranty 3.17 Service Policy 3.
.0 DESCRIPTION Detcon MicroSafe™ Model IR-622, combustible hydorcarbon gas sensors are non-intrusive “Smart” sensors designed to detect and monitor combustible hydorcarbon gas in air over the range of 0-100% lower explosive limit (LEL). One of the primary features of the sensor is its method of automatic calibration which guides the user through each step via instructions displayed on the backlit LCD.
Porous Membrane H H H H C H C H H H Optical Sample Gas Chamber Optical Filter Optical Filter Reference Detector Active Detector Lamp 3.0.2 Microprocessor Control Circuit The control circuit is microprocessor based and is packaged as a plug-in field replaceable module, facilitating easy replacement and minimum down time.
The sensors are packaged in a cast metal explosion proof enclosure. The enclosure is fitted with a threaded cover that has a glass lens window. Magnetic program switches located behind the transmitter module face plate are activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive operator interface with the sensor. All calibration and alarm level adjustments can be accomplished without removing the cover or declassifying the area.
tained, excessive loss in useable signal eventually gives way to noise and unstable readings. The optical sensor may, over long periods of time (3-7 years), lose its IR lamp source filament, and in this case an optical sensor modular replacement is required. The IR-622 has an extensive list of Fault Diagnostics to alert and pin-point operational problems. See section 3.10 3.
Clearing Time 90% < 35 seconds Repeatability ± 3% FS Range 0-100% (lower explosive limit) LEL Operating Temperature -40° to +175° F Accuracy ± 3% FS Sensor Warranty 5 year pro-rated Power Consumption Normal operation = 95 mA (2.3 watts); Full alarm = 123 mA (<3 watts) Zero Drift < 5% per year Output 3 relays (alarm 1, alarm 2, and fault) contact rated 5 amps @ 250 VAC, 5 amps @ 30 VDC; Linear 4-20 mA DC; RS-485 Modbus™ Input Voltage 22.5-28 VDC 3.
3.4.3.1 Program Status The program status scrolls through a menu that displays: * The gas type, range of detection and software version number. The menu item appears as: “LEL 0-100 V6.0” * The alarm set point level of alarm 1. The menu item appears as: “ALM1 SET @ ##%” * The alarm firing direction of alarm 1. The menu item appears as: “ALM1 ASCENDING” or descending. * The alarm relay latch mode of alarm 1. The menu item appears as: “ALM1 NONLATCHING” or latching. * The alarm relay energize state of alarm 1.
3.5.2 Sensor Location Selection of sensor location is critical to the overall safe performance of the product.
a) Remove the junction box cover and un-plug the control circuit by grasping the two thumb screws and pulling outward. b) Securely mount the sensor junction box in accordance with recommended practice. See dimensional drawing (Fig. 2). c) Observing correct polarity, terminate 3 conductor field wiring, RS-485 wiring, and applicable alarm wiring to the sensor base connector board in accordance with the detail shown in Figure 3.
settings of the alarms (jumpers removed) are normally de-energized relays, non-latching relays, and alarm points that activate during descending gas conditions. If a jumper tab is installed in the latch position, that alarm relay will be in the latching mode. The latching mode will latch the alarm after alarm conditions have cleared until the alarm reset function is activated. The nonlatching mode (jumper removed) will allow alarms to de-activate automatically once alarm conditions have cleared.
3.5.
Figure #5A Remote Transmitter IR-622-RT Remote Sensor IR-622-RS 56 RED BRN WHT BLK YEL BLU RED BRN WHT BLK YEL BLU 1234 3.6.2 Programming Magnet Operating Instructions Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the transmitter face plate. DO NOT remove the glass lens cover to calibrate or change programming parameters.
Program Switch #1 Plug-in Microprocessor Control Circuit CONTRAST PGM Display Contrast Adjust MODEL 1 detcon inc. HOUSTON, TEXAS IR-622 Menu Driven Display MicroSafe™ LEL Gas Sensor FLT ALM ALM 2 CAL 1 PGM 2 Alarm & Cal LEDs Figure #7 Program Switch #2 NOTE: If the sensor has been configured for calibration with a gas other than methane you will need to use that gas. See section 3.7 for further information on calibration gas.
NOTE 2: When a “cal fault” occurs, the sensor microprocessor retains its previous calibration references. Zero calibration is complete. 3.7.2 Calibration Procedure - Span CAUTION: Verification of the correct calibration gas level setting and calibration span gas concentration is required before “span” calibration. These two numbers must be equal. Calibration consists of entering the calibration function and following the menu-displayed instructions.
1. Upon entering the calibration menu, the 4-20 mA signal drops to 2 mA and is held at this level until you return to normal operation. 2. If during calibration the sensor circuitry is unable to attain the proper adjustment for zero or span, the sensor will enter into the calibration fault mode which will activate fault alarm functions (see section 3.10) and cause the display to alternate between the sensor’s current status reading and the calibration fault screen which appears as: “CAL FAULT”.
Both alarm 1 and alarm 2 levels are factory set prior to shipment. Alarm 1 is set at 20%; alarm 2 at 60%. Both alarms can be set in 1% increments from 10 to 90%. The following procedure is used to change alarm set points: a) First, enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30 seconds until the display reads “VIEW PROG STATUS”, then withdraw the magnet.
the calibration fault screen which appears as: “CAL FAULT.2”. The following conditions will cause a calibration fault: 1 - Zero calibration cannot converge. 2 - Auto span cannot converge (too noisy or too unstable). 3 - Span gas is not applied before 1 minute elapses. Fail-Safe/Fault Supervision Model IR-622 MicroSafe™ sensors are programmed for fail-safe operation.
The following section explains the details of the Modbus™ protocol that the IR-622 MicroSafe™ sensor supports. Code 03 - Read Holding Registers, is the only code supported by the transmitter. Each transmitter contains 6 holding registers which reflect its current status.
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1-Alarm 1 is latching 1-Alarm 1 Relay is energized 1-Fault is normally energized 1-Fault is latching 1-Fault Relay is energized 0-Alarm 1 is non-latching 0-Alarm 1 Relay is not energized 0-Fault is normally de-energized 0-Fault is non-latching 0-Fault Relay is not energized The following is a typical Master Query for device # 8: Field Name Slave Address Function Start Address Hi Start Address Lo No. of Registers Hi No.
3.13 OPTICAL SENSOR REPLACEMENT PROCEDURE Should the optical gas sensor element (part number 370-365871-212) require replacement, use the following procedure: 1 - (A) If the sensor is mounted in a classified area, system power to the transmitter must first be removed before proceeding further. (B) If in an unclassified area, remove front enclosure cover and unplug transmitter module. 2 - Remove lower half of sensor housing using an alan wrench (3 screws).
Bad 4-20 mA output or RS485 Output 1. Check that wiring is connected to correct terminal outputs. 2. Swap with a known-good transmitter to determine if transmitter is faulty Unstable output/Sudden Spiking/Nuisance Alarms 1. Check condulet for accumulated water. 2. Check transmitter and Terminal PCB for abnormal corrosion. 3. Determine if problem correlates with condensation cycles. 4. Add/change Detcon condensation prevention packet. 5. Check for unstable power supply. 6. Check for inadequate grounding. 7.
Programming Magnet Figure #8 Enclosure glass lens cover Plug-in control circuit Rain Shield Spash Guard Calibration Adapter IR Connector Board Enclosure less cover IR Sensor Housing Assembly Condensation Prevention Packet (replace annually) Field replaceable plug-in optical sensor the original purchaser and ends five years thereafter. The sensor element is warranted to be free from defects in material and workmanship.
LEGEND PGM1 - program switch location #1 PGM2 - program switch location #2 (M) - momentary pass of magnet (3) - 3 second hold of magnet (30) - 30 second hold of magnet INC - increase DEC - decrease # - numeric value AUTO SPAN AUTO ZERO PGM1 (3) PGM2 (3) CALIBRATION 1-ZERO 2-SPAN PGM1 (3) PGM1 (M) ALARM RESET NORMAL OPERATION PGM2 (30) PGM2 (M) ALARM RESET VIEW PROG STATUS SET ALARM 1 LEVEL SET ALARM 2 LEVEL SET CAL LEVEL PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M)
