Sierra Monitor Corporation 4501-05 Quick Start, Model 4501-XXToxic Gas Sensor Module, Page

Model 4501-XX Toxic Gas Sensor Module

3. QUICK START

3.1OVERVIEW

The gas sensor module has been supplied factory calibrated and ready for immediate installation and operation. An installer familiar with installation and operation of gas detection products can use this section to begin immediate use of the module.

3.2WIRING

Provide two conductor shielded wiring from the power supply/control device to the sensor module location. Use wire that is 16 AWG or larger.

3.3MODULE INSTALLATION

The 4501-XX can be mounted in a variety of configurations supported by the conduit. See figure 1-2 to determine which configuration is best for your specific application. The default configuration enables the modules to be put in line with other modules with the sensor element below the transmitter. To change the configuration simply remove the transmitter and rotate to the appropriate configuration and remount the standoffs and transmitter.

The module is designed to be installed on a ¾” conduit. Two important warnings:

•The installation must meet any hazardous environment codes for electrical equipment

•The sensor module enclosure mounting must be spaced far enough from any vertical surface to allow removal and replacement of the sensor assembly which is threaded into one ¾” conduit entry.

3.4TRANSMITTER INSTALLATION

To install the transmitter printed circuit assembly into the housing, carefully turn the faceplate so that the printing is in the correct horizontal position for the mounting configuration and slide the assembly over the two stand-offs in the enclosure.

Hand tighten the two captive panel thumb screws into the stand-offs. Replace the enclosure cover prior to providing power to the transmitter

•If the transmitter is installed in a classified hazardous area, replace the threaded cover prior to providing power.

3.5START-UP & OPERATION

To begin operation of the sensor module activate the instrument loop with 14-30 VDC. Each time the sensor module is powered up it will perform a warm-up for approximately 2.5 minutes (148 seconds). During this time the display will read “Warm. 148” and count down. The loop output will be held at 4 mA.

After the warm-up period has expired, the display will indicate the gas concentration. Also, the instrument loop will be released to output current in the range of 4 to 20 mA. The actual current is linear with the gas concentration and depends on the selected range. For instance, when the range of 0 to 50 PPM has been selected, a current of 4 mA corresponds to 0 PPM and a current of 20 mA corresponds to 50 PPM.

3.6ZERO STABILIZATION

All electrochemical sensors require at least 30 minutes on power prior to calibration. This allows the electrode potentials to equilibrate, resulting in a stable zero signal level.

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