Sierra Monitor Corporation 5100-06-IT, T12020 Model 5100-XX-ITToxic Gas Sensor Module, Page

Model 5100-XX-IT Toxic Gas Sensor Module

The enclosure should be replaced if the cover threads or conduit threads have been damaged, or if the enclosure has been damaged sufficiently that it no longer meets the required NEMA classification.

To replace the enclosure follow the transmitter and sensor assembly removal instructions, remove the damaged enclosure from its conduit, install a new enclosure and replace the transmitter and sensor assembly.

6.3TRANSMITTER REPLACEMENT

The transmitter assembly should be replaced when it is determined that it is unreliable, noisy or cannot be adjusted for calibration. This may occur due to age, corrosion or failed components.

To replace the transmitter assembly:

a.Remove the cover of the main enclosure

b.Unscrew the two thumb screws in the top of the cover plate, lift the assembly and rotate 90o to relieve the wiring service loop

c.Unplug the sensor connector from the transmitter

d.Plug connector into new transmitter (be sure to match numbers between connector and socket).

e.Restore power and allow a minimum of 3 hours for stabilization before re-calibration

6.4SENSOR REPLACEMENT

The gas sensor which is located inside the sensor assembly housing can be replaced without replacement of the housing. The gas sensor needs replacement when:

The “CAL-FAIL” message appears after calibration

The sensor output signal is noisy, causing erroneous gas level readings

To replace the sensor:

a.Confirm that system power has been removed

b.Remove the gas sensor module enclosure cover,

c.Unscrew the two thumb screws in the top of the faceplate, lift the transmitter assembly and rotate 90o to relieve the wiring service loop.

d.Unplug the sensor connector from the transmitter

e.Unscrew the old sensor assembly from the enclosure conduit hub. Remove the sensor assembly with its harness

f.Unscrew sensor housing cover from the sensor (be sure to loosen the set screw first)

g.Carefully pull the old sensor straight up from the socket

h.Press the new sensor into the socket.

i.Reverse the preceding steps to install the sensor assembly.

j.Allow the new sensor to stabilize for a minimum of 3 hours and then calibrate using the procedure in Section 6.

6.5INSTALLATION INSPECTION

Prior to system start-up or trouble shooting the entire system should be visually inspected. The following are guidelines for that inspection:

6.5.1.1CONTROLLER INSTALLATION

•Controller installed in conformance to instruction manual recommendations.

•AC power is correctly grounded.

•Hot AC and relay connections have safety covers installed.

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