Sierra Monitor Corporation 5100-06-IT - Manual (Page 10)

Model 5100-XX-IT Toxic Gas Sensor Module
Page: 6
2. CAUTIONS & WARNINGS
2.1 INTRODUCTION
Although the IT Transmitter Modules are designed and constructed for installation and operation in industrial
applications including “hostile” environments, caution should be taken to insure that the installation is made in
compliance with this instruction manual and that certain procedures and conditions are avoided. This chapter
discusses the necessary cautions. Read the entire chapter prior to installation of the equipment.
2.2 GAS SENSOR MODULES - GENERAL
Avoid installing sensor modules where they will be unnecessarily exposed to wind, dust, water (i.e. direct hose
down), shock, or vibration. Observe temperature range limitations.
Sensors may be adversely affected by prolonged exposure to certain materials. Loss of sensitivity, or
corrosion, may be gradual if such materials are present in low concentrations. These materials include:
Halides (compounds containing chlorine, fluorine, bromine, iodine), acid vapors, caustic liquids or mists.
Care has been taken by the manufacturer to ship modules in protective packaging to avoid contamination prior
to installation. It is recommended that the modules remain protected during installation and that the covering
be removed immediately prior to system start-up.
During normal use the O
2
, CO, H
2
S, and SO
2
sensors are protected from dirt and oil contamination by a
sintered metal cover. If this cover becomes clogged, the response of the sensor will be reduced. Protect the
sensor from contamination by careful placement, or by use of rain shields and dust shields.
Sensor modules must not be painted. Paint may contain compounds which will contaminate the sensor. Paint
will cause clogging of the sintered metal cover and will cause difficulties during attachment of the calibration
head or other maintenance activity. It is recommended that the module be tagged
"DO NOT PAINT"
.
2.3 WIRING
The manufacturer recommends that extra caution be taken where the installation is near any sources of
electromagnetic or radio frequency interference. Precautions include:
• Avoid running sensor module cable close to high power cables, radio transmission lines, or cables
subject to pulses of high current.
• Avoid running cables near large electric motors or generators.
• When the sensor module is to be operated in analog (4-20mA output) mode shielded cable is required.
• When shielding is used, it is recommended that shields be grounded at the controller and nowhere
else.
• All splices must be via either a termination hardware system or soldered. Improperly spliced cable can
result in corrosion, resistance changes and system errors. The use of wire nuts and crimp-on
connectors is unacceptable.
NOTE
Installation and wiring must be in accordance with the National Electrical Code.
Voltage AC conductors are not to be run in the same conduit as voltage DC
conductors.
2.4 CALIBRATION FREQUENCY
The 5100-XX-IT calibration frequency is six months (180 days). However, prudent gas detector maintenance
practices normally suggest a simple recalibration following incidences of exposure to high levels of gas that
would lead to alarm activation within any system utilizing the output of the gas sensor module.