Emerson 3051N manual Grounding the Transmitter Case, Environmental Considerations

Page 48

Rosemount 3051N

Reference Manual

00809-0100-4808, Rev CA June 2008

Grounding the Transmitter Case

ENVIRONMENTAL CONSIDERATIONS

Access Requirements

Cover Installation

The transmitter case should always be grounded in accordance with national and local electrical codes. The most effective transmitter case grounding method is direct connection to earth ground with minimal impedance. Methods for grounding the transmitter case include:

•Internal Ground Connection: The Internal Ground Connection screw

is inside the FIELD TERMINALS side of the electronics housing. This screw is identified by a ground symbol ( ), and is standard on all Rosemount 3051N transmitters.

•External Ground Assembly: This assembly is included as standard with the transient protection terminal block (T1) included with the Rosemount 3051N

NOTE

Grounding the transmitter case using the threaded conduit connection may not provide a sufficient ground. The standard transient protection terminal block (T1) does not provide transient protection unless the transmitter case is properly grounded. Use the above guidelines to ground the transmitter case. Do not run the transient protection ground wire with signal wiring as the ground wire may carry excessive current if a lightning strike occurs.

The following guidelines can help optimize transmitter performance. Mount the transmitter to minimize ambient temperature changes, vibration, mechanical shock, and to avoid external contact with corrosive materials. “Specifications and Reference Data” in Section 5 lists transmitter temperature operating limits.

When choosing an installation location and position, take into account the need for access to the transmitter.

Process Flange Orientation

Mount the process flanges with sufficient clearance for process connections. For safety reasons, place the drain/vent valves so the process fluid is directed away from technicians when the vents are used. In addition, consider the possible need for a testing or calibration input.

Housing Rotation

See “Housing Rotation” in Section 3.

Terminal Side of Electronics Housing

Mount the transmitter so that the terminal side is accessible. A 0.75-inch (19

mm)clearance is required for cover removal. Use a conduit plug on the unused side of the conduit opening.

Circuit Side of Electronics Housing

Provide 0.75 inches (19 mm) clearance for cover removal. Three inches of clearance is required for cover removal if a meter is installed.

Exterior of Electronics Housing

The integral span and zero adjustments are located under the label plate on the top of the transmitter. Allow a minimum of 1.0 inch of clearance above the transmitter if you intend to use the integral zero and span adjustments.

Always install the electronics housing covers metal-to-metal to ensure a proper seal.

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Contents Reference Manual Important Notice -- Errata Rosemount 3051N Return of Material Changes from June 2006 to June OldChanges Rosemount 3051N Table of Contents Installation TroubleshootingSpecifications Reference Data Options Appendix aHart Communicator Glossary Index Using this Manual Section IntroductionRosemount 3051N Overview Safety Messages Transmitter FunctionsAlarm Level Verification TransmitterSecurity Configuring Transmitter Alarm and Security Jumper Procedure Physical Removal Local Zero and Span Local KeysElectronics Board Setting the Loop to Manual Wiring Diagrams Bench Hook-up Wiring Diagrams Field Hook-up Review Configuration Data Check OutputProcess Variables Sensor Temperature Basic SetupSet Process Variable Units Set OutputRerange Rerange with a Communicator OnlyRerange with a Pressure Input Source and a Communicator Span and Zero Adjustment Buttons Detailed Setup Diagnostics ServiceTransmitter Test Loop TestCalibration Transmitter Bench Calibration Tasks Field Calibration Tasks Configure the Analog Output Parameters Calibration OverviewSensor Trim URVZero Trim Typical Zero vs Non-zero-Based Application IllustrationsFull Trim Digital Trim Connection Drawing 4-20 mA TransmittersDigital-to-Analog Trim Using Other Scale Recall Factory Trim Recall Factory Trim- Sensor TrimRecall Factory Trim- Analog Output Analog Output TrimZero Effect HTc = URV + S URV Ps Rosemount 3051N Section Installation Rosemount 3051N Typical Installation Flowchart General Considerations Special Draft Range ConsiderationsMechanical Considerations 156 181 16 x 11/4 Bolts for Mounting to 54.1 Transmitter 120 127 66.8 Traditional Flange Option Code H2 Dimensional Drawing Mounting Rosemount 3051N GAS or Liquid Service GAS Service Steam Service Process Connections Housing Rotation Power SupplyElectrical Considerations Wiring Power Supply Load LimitationsAccess Requirements Cover Installation Grounding the Transmitter CaseEnvironmental Considerations Troubleshooting Symptom Corrective Actions Returning Rosemount Products and MaterialsNuclear Specifications SeismicModel Range Code Hydrostatic Test Pressure Performance Specifications Ambient Temperature Effect12Reference Accuracy DriftPower Supply Effect Load Effect Mounting Position Effect Overpressure Effect Static Pressure EffectRange Code Overpressure Effect Range Code Static Pressure Zero Effect1Functional Specifications ServiceTemperature Limits OutputSpan and Zero, Zero Elevation, Suppression Range Minimum Span Upper URL Lower LRLRange Code Minimum Time Constant Tc Including Dead Time Td Maximum Working Pressure12Static Pressure Limits Overpressure Limits Burst PressurePhysical Specifications Materials of Construction Option Code Description Add Ordering Information Configuration Information Housing Material Conduit Entry SizeMounting Bracket Options Meters optionalDate  On Rosemount 3051N Exploded View with Coplanar Process Flange Rosemount 3051N Rosemount 3051N Overview Safety Messages LCD Meter Section OptionsCustom Meter Configuration Installing the Meter Exploded View of the Rosemount 3051N with Optional LCD MeterRosemount 3051N Diagnostic Messages ErrorPress Limit Operation Mounting BracketsTraditional Flange H2 Transient Protection Terminal Block T1Transient Protection Terminal Block T1 Rosemount 3051N Introduction Safety Messages Appendix a Hart CommunicatorRosemount 3051N Online Menu Function Hart Fast Key Sequence Figure A-3. Rosemount Hart terminal access door Connections and HardwareFigure A-4. Bench Hook-up MA Transmitters Rosemount Communicator KeysAction Keys Function Keys Alphanumeric and Shift KeysData Entry Fast Key Sequences Fast Key Sequence Conventions Fast Key Sequence ExampleMenus Functions Main MenuOnline Menu Touch Alphanumeric Keys Multifunction LEDTouch Screen Multifunction LED Processing IndicationRosemount 3051N Diagnostic Messages Fast Key Sequences Hot Key optionsMessage Description Rosemount 3051N Uploadvariable Rosemount 3051N Rosemount 3051N Glossary Smart Family Index 00809-0100-4808, Rev CA June Security Page ¢00809-0100-4801V¤
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