Detcon IR-522 User 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:
“LEL 0-100 V6.0”
* The calibration gas level setting. The menu item appears as:
“CalLevel @ xx%”
* Sensor temperature in °C appears as:
“TEMPERATURE xx °C”
* The estimated remaining sensor life. The menu item appears as:
“OPTICS AT 100%”
3.4.3.2 Calibration Level Adjustment
The Calibration level is adjustable from 10% to 90% LEL. 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-522 combustible gas sensor assemblies require three conductor connection between power sup-
plies 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
22
3A
16
10A
20
5A
14
20A
18
7A
12
25A
The RS-485 (if applicable) requires 24 gauge, two conductor, shielded, twisted pair cable between sensor and host
PC. Use Belden part number 9841. Two sets of terminals are located on the connector board to facilitate serial loop
wiring from sensor to sensor. Wiring designators are A & B (IN) and A & B (OUT).
3.5.2 Sensor Location
Selection of sensor location is critical to the overall safe performance of the product. Five factors play an important
role in selection of sensor locations:
(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
(5) Maintenance access
Model IR-522 Combustible Hydrocarbon Sensor PG.8