Define the area classification, Decide classification method, Determine hazard – Rockwell Automation 1794-APBDPV1 FLEX I/O PROFIBUS Adapter User Manual User Manual

Page 108: Determine temperature rating

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Publication 1794-UM064B-EN-P - May 2014

96 Apply FLEX I/O Modules

Define the Area
Classification

Before you can determine what components will make up your FLEX I/O
system, you must define the area in which that system will operate. You must
determine the following:

• Classification method
• Hazard
• Temperature rating

Decide Classification Method

Your application location will usually decide whether the classification method is
Zone or Class/Division, but the system designer may make this determination.
FLEX I/O IS CERTIFIED FOR ZONE METHOD ONLY. Certification is
pending for Division method.

Determine Hazard

Hazard, typically gas, dust, or fibers, is determined by the material being
processed. For example, a coal mine will generally be rated for dust and methane
gas hazards. FLEX I/O IS CERTIFIED FOR GAS HAZARD ONLY.
Certification is pending for attaching wiring to FLEX I/O modules from a dust
and fiber hazardous area.

Determine Temperature Rating

The spontaneous ignition temperature of the hazard in your application
determines the temperature rating. For example, an application with a hydrogen
hazard may use equipment with a temperature rating of T1 because hydrogen’s
ignition temperature is 550 °C. FLEX I/O IS CERTIFIED AS A T4 SYSTEM.

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