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937-PP001

937-PP001
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Bulletin 937 Intrinsic Safety Modules Specialized Solutions For Hazardous Location Applications Features and Benefits • Simple maintenance with integrated diagnostics and quick change of modules during ongoing operation • Simple configuration using DIP switches or Field Device Tool software • Comprehensive standards compliance, including up to SIL3 compliance for easy and reliable planning and documentation • Horizontal or vertical mounting with no reduction in operational ratings • Line fault detection for field circuits • Power Rail for drastically reduced wiring, collective error messaging, for efficient troubleshooting and installation • Variety of module types to meet applications needs, including: - Isolated Barriers for complete electrical isolation of intrinsic safety circuits - Converter Barriers to change readings from sensors to industry standardized signals - Zener Barriers for simple limiting of energy allowed through to hazardous locations An intrinsic safety approach can be more cost-effective than other hazardous location protection/mitigation strategies in Class l, Division 1 (Zones 0 and 1) locations. A signal interface bridge between hazardous locations and the control system Bulletin 937 Intrinsic Safety Modules connect intrinsically safe rated equipment – such as transmitters, solenoids, proximity sensors and encapsulated assemblies—with control systems. An intrinsic safety approach can be more cost-effective than other hazardous location protection/ mitigation strategies in Class l, Division 1 (Zones 0 and 1) locations. Intrinsic safety circuits are designed to operate at low enough energy levels that igniting hazardous materials will be averted--even in the event of a fault condition, such as a short circuit. Intrinsic safety circuits do not require expensive inert gas purging/pressurization or “explosion-proof”/ containment strategies for hazardous locations. Bulletin 937 modules are part of the Allen-Bradley signal interface family of products. This family also includes Bulletin 931 signal conditioners, which can be used in less hazardous locations where intrinsic safety capabili

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These modules are available in a range of options that provide for a wide range of functionality in hazardous location applications in industries such as oil and gas, chemical/petrochemical and others. The Bulletin 937 product family consists of: Isolated Barriers With galvanic optical or transformer isolation these modules provide an interface to the intrinsic safety circuit that is electrically separated from the control system, and does not require a ground between the module and the intrinsically safe device. Available in high density (12.5 mm/0.5 in) and standard (20mm/0.8 in)widths....

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Converter Barriers Converters add functionality to the isolators by receiving signals from a hazardous area instrument i.e., temperature sensors, or load cells and then converting them to an industry standardized signal such as 0/4…20mA or 0/2…10V. Pulse evaluation units process a frequency signal at the input. A lead fault monitoring system signals a lead breakage or lead short-circuit on the signal cables. Universal Temp Converter HART Loop Converter Strain Gauge Converter Universal Temperature Converters are designed to connect RTDs, thermocouples or potentiometers in the hazardous area,...

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Zener Barriers Zener barriers have long been a cost-effective solution for providing an intrinsically safe interface with field devices located in the hazardous area. Allen-Bradley Zener barriers provide protection for electrical signals within hazardous areas and feature a narrow profile of just 12.5 mm to maximize control panel space. Zener barrier prevents the transfer of unacceptably high energy from the safe area into the hazardous area. These Zener barriers have a positive polarity, which means the anodes of the Zener diodes are grounded. Depending on the application, increased or...

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