Detcon IR-642 - Manual (Page 8)

3.4.3 Program Mode
The program mode provides a program status menu, allows for the adjustment of alarm set point levels, and the
selection of the calibration gas level setting..
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: “CO2 RANGE V6.0”
* The alarm set point level of alarm 1. The menu item appears as: “ALM1 SET @ ##%”
* The alarm f iring 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. The menu item appears as: “ALM1 DE-ENERGIZED” or energized.
* The alarm set point level of alarm 2. The menu item appears as: “ALM2 SET @ ##%”
* The alarm f iring direction of alarm 2. The menu item appears as: “ALM2 ASCENDING” or descending.
* The alarm relay latch mode of alarm 2. The menu item appears as: “ALM2 LATCHING” or nonlatching.
* The alarm relay energize state of alarm 2. The menu item appears as: “ALM2 DE-ENERGIZED” or energized.
* The alarm relay latch mode of the fault alarm. The menu item appears as: “FLT NONLATCHING” or latching.
* The alarm relay energize state of the fault alarm. The menu item appears as: “FLT ENERGIZED” or deenergized.
* The calibration gas level setting. The menu item appears as: “CalLevel @ #.##%”
* Identif ication of the RS-485 ID number setting. The menu item appears as: “485 ID SET @ ##”
* Sensor temperature in °C appears as: “TEMPERATURE ## °C”
* The estimated remaining sensor life. The menu item appears as: “OPTICS AT 100%”
3.4.3.2 Alarm 1 Level Adjustment
The alarm 1 level is adjustable over the range 10 to 90% of full-scale range. For CO2 gas sensors, the level is factory
set at 20% of full-scale range. The menu item appears as:
“SET ALM1 @ #.##%”
3.4.3.3 Alarm 2 Level Adjustment
The alarm 2 level is also adjustable over the range 10 to 90% of full-scale range. For CO2 gas sensors, the level is
factory set at 60% of full-scale range. The menu item appears as:
“SET ALM2 @ #.##%”
3.4.3.4 Calibration Level Adjustment
The Calibration level is adjustable from 10% to 90% of full-scale range. The menu item appears as: “CalLevel @ #.##%”
3.5 I
NSTALLATION
Optimum performance of ambient air/gas sensor devices is directly relative to proper location and installation practice.
3.5.1 Field Wiring Table (4-20 mA output)
Detcon Model IR-640/IR-642 CO2 sensor assemblies require three conductor connection between power supplies
and host electronic controllers. Wiring designators are + (DC), – (DC) , and mA (sensor signal). Maximum single
conductor resistance between sensor and controller is 10 ohms. Maximum wire size for termination in the sensor
assembly terminal board is 14 gauge.
AWG Meters Feet
20 240 800
18 360 1200
16 600 2000
14 900 3000
Note 1: This wiring table is based on stranded tinned copper wire and is designed to serve as a reference only.
Note 2: Shielded cable may be required in installations where cable trays or conduit runs include high voltage
lines or other sources of induced interference.
Note 3: The supply of power must be from an isolating source with over-current protection as follows:
AWG Over-current Protection AWG Over-current Protection
Detcon Model IR-640/IR-642 Carbon Dioxide Sensor PG.8