Univex 5100-02-IT, IT Series Product Description, 1.1GENERAL, 1.2PRODUCT CONFIGURATION, Page

Model 5100-02-IT Combustible Gas Sensor Module

1. PRODUCT DESCRIPTION

1.1GENERAL

The Model 5100-02-IT Catalytic Bead Combustible Gas Sensor Module is a member of the Sentry Information Technology ”IT” family of gas sensor transmitter modules. IT modules offer a broad array of features including:

•Integral Alphanumeric display

•180 day calibration frequency

•Integral alarm relays (3)

•4-20 mA output

•Modbus® RTU interface

•SMC Sentry interface

•316 Stainless steel enclosure option

•Remote alarm reset

•Auxiliary relay option

•Remote sensor option

•Auxiliary connector option

IT modules are designed, and approved for installation and operation in hazardous locations.

1.2PRODUCT CONFIGURATION

Various module configuration options are available. Where applicable, these options are factory configured prior to shipment.

1.3THEORY OF OPERATION

Catalytic bead gas sensors detect gas by comparing the resistance of two heated elements. One element is catalytic to enhance the burning of combustible gases, the other element is passive. Electronic circuits are used to compare the change in the catalytic bead resistance relative to the passive bead. The relative change is calibrated to determine the concentration of the gas of interest.

1.4MODES OF OPERATION

1.4.1SENTRY INTERFACE

All IT gas sensor modules can be installed on Sierra Monitor Sentry Model 5000 controllers. Catalytic bead modules communicate as a combustible gas sensor module (Type 2 communication) and are automatically detected by the Sentry controller. When it is installed in a Sentry system the IT module must have a unique address which can be established by setting an address between 1 and 8 on the rotary switch accessible from the cover plate as illustrated in Figure 3-1. Figure 3-4 in this manual provides the wiring terminations for connections to the Sentry controller.

When the module is operated in conjunction with a Sentry controller, the alarm relay setup (See section 4.3) should be set to “Sentry”, allowing the Sentry controller to manage alarm relay action rather than the 5100-02-IT Gas Sensor Module.

An available option, applicable only to Sentry installations, is a connector card which allows daisy chain installation using the Sentry multiplex capability. Use of the connector card reduces costs by avoiding the requirement for wiring junction boxes. The connector card has two sets of connections, allowing for a continuous run to the next module.

®Registered trademark of Schneider Electric.

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