EFJohnson 7780 Possible Ignition Sources, Intrinsically Safe and Nonincendive Ratings

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GENERAL INFORMATION

tion. When electrical equipment is given this rating, the equipment is considered incapable of releasing suffi- cient electrical and thermal energy under normal oper- ation or specified fault conditions per the testing standard to cause ignition of a specific flammable or combustible atmosphere in its most easily ignited con- centration. In other words, this transceiver should not cause a fire or explosion when used in certain flamma- ble atmospheres.

Fault - A defect or electrical breakdown of any compo- nent, spacing, or insulation which alone or in combina- tion with other faults may adversely affect the electrical or thermal characteristics of the intrinsically safe circuit (for example, a shorted transistor).

1.10.3 POSSIBLE IGNITION SOURCES

When a transceiver is checked by Factory Mutual, possible sources of ignition are checked. These sources may be electrical (spark) or thermal (heat). The following could be sources of spark ignition:

•Discharge of a capacitive circuit by a fault such as a short circuit.

•Interruption of an inductive circuit.

•Intermittent making or breaking of a resistive circuit.

•Hot-wire fusing.

The following could be sources of thermal ignition:

•Heating of a small-gauge wire or PC board trace.

•High surface temperature of components.

1.10.4INTRINSICALLY SAFE AND NONINCENDIVE RATINGS

This transceiver is rated intrinsically safe for some types of hazards and nonincendive for other types of hazards. An intrinsically safe rating applies to operation in Division 1 areas, and a nonincendive rating applies to operation in Division 2 areas (see next section). The difference between these ratings is as follows:

The intrinsically safe rating is a higher rating because more severe conditions must be met. To be approved for this rating, the transceiver must not cause

ignition of a particular atmosphere if two of the faults specified in the testing procedure occur. In other words, it must be able to withstand two simultaneous unrelated breakdowns without causing ignition. To receive a nonincendive rating, the transceiver needs to withstand only a single fault without causing ignition of a particular atmosphere.

1.10.5CLASSIFICATION OF HAZARDOUS AREAS AND ATMOSPHERES

Introduction

This transceiver has been submitted for approval to operate in the following hazardous atmospheres and areas. Contact your sales representative or refer to the label on the back of the transceiver to determine the specific atmospheres and areas for which approval was obtained.

Intrinsically Safe - Class I, II, and III, Division 1, Groups C, D, E, F, and G.

Nonincendive - Class I, Division 2, Groups A, B, C, and D.

Temperature Code - T3C

The meanings of these Class, Division, and Group designations are as follows.

Atmosphere Classification (Class/Group)

For the purposes of testing and approval, various atmospheric mixtures have been grouped on the basis of their hazardous characteristics. Equipment is approved for a class of material and also for the specific gas, vapor, or dust in that class. Class I mate- rials include gases and vapors, and Class II materials include combustible dusts. The various classes and some specific groups of gases in each are shown in Table 1-2.

Area Classification (Division)

Areas are either Division 1, 2, or 3 as shown in Table 1-3. Since a Division 1 area is considered the most hazardous, a transceiver approved for a specific Division 1 area can also be used in the same Division 2 Class/Group.

 

November 1999

1-5

Part No. 001-7780-500

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Contents 7780 Page Page Table of Contents Table of Contents CONT’D List of Figures List of TablesScope of Manual Equipment Description General InformationTransceiver Identification AccessoriesFactory Customer Service Part Number BreakdownFactory Returns AccessoriesAccessory Toll-Free 800Definitions Replacement PartsInternet Home Intrinsically Safe Information Classification of Hazardous Areas and Atmospheres Temperature Code T3CPossible Ignition Sources Intrinsically Safe and Nonincendive RatingsArea Classification Accessing PC BoardsMaterial Classification Typical Hazard Group ClassRemoving Logic Unit Removing RF UnitGeneral SpecificationsControls and Display FeaturesTransceiver Operation Low-Battery Indicator Amber TX Indicator Red Indicates when the transmitter is keyedDisplay DisplayFront Panel Keys Full Keypad Model Backlight Turning Power on and Setting VolumeOption Switches General OperationSee Option Switch FunctionsFunction Conv Scanning Tone ENABLE/DISABLEConventional and SMARTNET/ Smartzone Operation Monitoring Before Transmitting Conventional FeaturesDisplay Mode Selection Call Guard Squelch Monitor ModeBusy Channel Lockout Conventional Mode Scanning Penalty TimerConversation Timer Power Output SelectPriority Channel Sampling Standard Conventional Calls DTMF/ANI SignalingEnhanced Private Conversation Calls SMARTNET/SMARTZONE FeaturesViewing Unit ID Standard Group CallsTransceiver Operation Private Conversation II Calls Telephone Calls Call Alert Sending Status Conditions Emergency Alarm and CallMessaging Dynamic Regrouping Failsoft OperationSMARTNET/SMARTZONE Scanning Supervisory Tones Zone Change Parameter Keypad ProgrammingMenu Description Channel Parameters Channel Change ParameterSystem Parameters Computer Description Programming SetupPctrunk Software Installation Transceiver ProgrammingHelp Files Connecting RPI to Computer and TransceiverStarting and Exiting Programming File TypesCreating and Displaying Systems Screen Pop-Up Buttons and File Size IndicatorProgramming Procedure File Size IndicationMenu Bar Menu CommandsWindow Menu Radio Type MenuDownload Menu Upload Menu Systems MenuZones DefaultsRADIO-WIDE Parameter Screens BandAssign Function Buttons Radio Wide Scan ListRadio-Wide Scan List Screen Modify List ScreenHot Dtmf RADIO-WIDE Conventional ScreenRADIO-WIDE SMARTNET/SMARTZONE Screen Full Spectrum CC ScanConventional System General Screen Adjustable ParametersRADIO-WIDE Portable Options Screen Programming Conventional Systems and ChannelsScan List Button TimersConventional System Modify Scan List Screen Keypad EditingPriority Channel Selection Scan TimersSetting UP Conventional Channels Selected Channel Conventional Channel Screen ParametersTx Time-Out Transmit PowerSignaling Channel TypeSplinter Channels Restricted AccessTime-Out Timer ISW Delay TimePrivate Call SMARTNET/SMARTZONE System Other ID’S ScreenSMARTNET/SMARTZONE System Phone Interconnect Screen Phone InterconnectFailsoft Channel SMARTNET/SMARTZONE System Emergency Settings ScreenEmergency Alarm SMARTNET/SMARTZONE System Talk Groups ScreenMessage Aliasing Screen SMARTNET/SMARTZONE System Lists ScreensTrunking Phone List Screen Control Channels Screen Announcement Groups ScreenTrunking Call List Screen SMARTNET/SMARTZONE Channel Screen Parameters Setting UP SMARTNET/SMART- Zone ChannelsStatus Aliasing Screen Other Screen Parameters SMARTNET/SmartZone Channel ScreenRecommended Tone Call Guard Codes Freq Call Guard CTCSS/DCS Codes and TonesMHz Channels MHz Channels MHz Channels MHz Channels MHz Channels MHz Channels Synthesizer Description Power Switching and RegulationPower Switching Circuit DescriptionCharge Pump Q1, Q2, Loop Filter VCO and Tcxo ModulationSynthesizer Chip IC1 If Amplifier Q2, LIMITER/DETECTOR IC3 Receiver Circuit DescriptionRF Amplifier Q1, First Mixer Q2 Amplifier Q9, Driver Q8 Antenna Switch and LOW-PASS FilterSquelch Circuit IC4A/B, IC5A Transmitter DescriptionReceive Audio Processing Control Logic and DisplayPin Port Name Input or Description Active High Output Microprocessor IC306 Pin DescriptionsHvfulswlrq Receive Data FILTER/DETECTOR IC102A/B, IC107A/B Audio Amplifier IC104-IC106Receive and Transmit Data Processing Transmit Audio Processing Transmit Data Filter IC206B/ IC206ASmartnet Data Processing LOW-PASS Filter IC205A/BFunction Fahrenheit Celsius Battery Pack and Charger InformationBattery Pack Power Setting Operating TimeBattery Pack and Charger Information Test Setup Alignment Procedure and Performance TestsMm/3/32 Mm/1/8 Phone Jack Tune Software HqhudoMain Pctune Screen Preliminary SetupModulation Balance Transmit Frequency and PowerTransmit Power Adjustment Screen High Power Level = 3.0 watts Low Power Level = 1.0 wattData Deviation Squelch AdjustRssi Adjust Audio DeviationReceiver Performance Tests Performance TestsTransmit Modulation Power OutputTransmitter Performance Tests Transmit FrequencyThis page intentionally left blank Ref No Description Parts ListDisplay Assembly Chassis PartsDisplay Assembly KEY AssemblyIf Assembly If AssemblyKEY Assembly RF Unit PLL AssemblyRF Unit NJM2904V-TE1 IC RF Unit Logic Unit Logic Unit TDA7233D IC Logic Unit 200K ERJ3GE MP35 MP18 MP25 EP2 KEY Front PanelEP1 MP32 MP33 MP27 MP34 MP28 MP29 MP23 MP22 MP30 MP24 MP26 MP18 PLL Board Bottom View Schematic Diagrams and Component LayoutsPLL Board TOP View If Board Bottom View If Board TOP ViewRF Unit Transceiver Block DiagramMIC RF Board TOP ViewIf AMP RF Board SchematicHD1 Logic Board TOP ViewReceive Audio Processing Logic Board SchematicGND KEYR3 KEYR2 KEYR1 KEYR0 KEYS3 KEYS2 KEYS1 KEYS0 GND Display Board Bottom ViewDS3 DS4 DS5 Display Board SchematicKEY Board Back View KEY Board Front ViewS S R R R R KEY Board SchematicScan HC2 HC7 HC8 HC3 Schematic Diagrams and Component Layouts
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