Hardware reference guide

Intrinsically Safe Modules
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35013379 11/2011
15.1 Intrinsically Safe Modules - General Information
Intrinsically Safe Modules – General Description
Introduction
The following information is specifically concerned with the application of intrinsic
safety with regards to the installation and field wiring of the Quantum Intrinsically
Safe series of modules. It provides a general description of intrinsic safety and how
it is accomplished in Quantum modules, how they should be installed, precautions
that should be observed, and wiring and grounding practices that must be followed.
Intrinsic Safety
Intrinsic safety is a technique for ensuring that electrical energy supplied to circuits
in a hazardous area is too low to ignite volatile gases either by spark or thermal
means. Intrinsically safe circuits use energy limiting devices known as intrinsically
safe barriers to prevent excess electrical energy from being applied to electrical
equipment located in the hazardous area.
Module Location
The Quantum Intrinsically Safe family of modules are entity certified to be installed
in safe areas to monitor/control intrinsically safe apparatus located In hazardous
areas.
Intrinsically Safe Barriers
All Quantum Intrinsically Safe modules use galvanic isolation to provide the
intrinsically safe barrier between them and the field devices located in hazardous
areas. Opto-isolators are located within the modules between the field side and the
Quantum backplane bus circuitry. The maximum agency specified intrinsically safe
parameters are:
Intrinsically Safe Power Supply
DC/DC converters in Quantum Intrinsically Safe modules provide intrinsically safe
power to field devices located in hazardous areas. No external field power is
required where these modules are installed.