EFJohnson 8500 manual Classification of Areas Division, Classification of Atmospheres Class/ Group

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INTRINSICALLY SAFE CLASSIFICATION

Classification of Areas (Division)

Areas are classified as Division 1or 2 as shown below. Since a Divi- sion 1 area is considered most hazardous, a transceiver approved for a specific Division 1 atmosphere can also be used in the same Division 2 atmosphere. The intrinsically safe rating applies to Division 1 areas and the nonincendive rating applies to Division 2 areas.

Division

Area

1An area where there is or could be an explosive atmosphere most of the time in normal operations.

2An area where an explosive atmosphere exists only as a result of a fault (something going wrong).

Classification of Atmospheres (Class/ Group)

For the purposes of testing and approval, various atmospheric

mixtures have been grouped on the basis of their hazardous characteris- tics. Equipment is approved for a class of material and also for the specific group of gas, vapor, or dust in that class. Class I materials include gases and vapors, and Class II materials include combustible dusts. The typical hazardous materials in each group and class are shown in the following table.

ATMOSPHERE CLASSIFICATION

Typical Hazard

Group

Class

Acetylene

A

1

Hydrogen

B

1

Ethylene, ethyl ether, cyclopropane

C

1

Gasoline, naphtha, butane, propane, alcohol

D

1

acetone, benzol, natural gas

 

 

Metal dust including aluminum, magnesium,

E

2

and their alloys

 

 

Carbon black, coal or coke dust

F

2

Flour, starch, or grain dusts

G

2

Ignitable fibers/flyings such as rayon and cotton

–

3

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Contents Series Safety Information Battery Recycling Information Page Quick Reference Guide Page Table of Contents Operation with Optional Remote Control Unit Front Panel Controls ControlsControls Optional Keys for Telephone Calls Front Panel Display Display InformationDisplay Information Receiving a Standard Call Standard CallsIntroduction Placing a Standard CallPlacing a Special Call Special CallsReceiving a Special Call Landside-Originated Calls Additional Phone Mode InformationDialing The Number Intercept Tone Supervisory TonesKey Press Tone Clear-To-Talk ToneConfirmation Tone Proceed Dialing Tone System ScanCall Proceed Tone End Call ToneTransmitting In Scan Scan Resume DelaySystem and Group Lockout Clear-To-Talk Other FeaturesScanning Multi-Net Systems Scanning Conventional SystemsGroup Scan Time-Out TimerRTN Return Key Call IndicatorEmergency Button Transmit Inhibit Keypad DisablePriority Calls High/Low Power Select Key Press Tone DisableGroup Select MULTI-NET and Conventional ModesChannel Monitoring Supervisory TonesTransmit Disable When Busy Conventional Mode OperationMonitoring Before Transmitting Call Guard Squelch Receive-Only and Talk-Around ChannelsOperation with Optional Remote Control Unit Control Unit Controls Miscellaneous Operating Information Operation with Optional Remote Control Unit Sending Status Information Miscellaneous InformationAuto-Registration System Operator Programming Busy QueuingDisplay Messages Setting Volume LevelBattery Pack Rechargeable Battery PackTransceiver Operation At Extended Range Speaking Into MicrophoneFCC Licensing Intrinsically Safe Classification Transceiver ServiceClassification of Atmospheres Class/ Group Classification of Areas DivisionApproved
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