Emerson 3051N manual Wiring, Power Supply Load Limitations

Page 47

Reference Manual

00809-0100-4808, Rev CA June 2008

Rosemount 3051N

FIGURE 3-7. Power Supply Load Limitations.

Max. Loop Resistance = 43.5 (Power Supply Voltage – 10.5) ohms

Load (ohms)

1935
1500
1500
1000					Design
					Design
500					Region
0

10.5	20	30	40	55
		Voltage (V dc)

	Communication requires a minimum loop resistance of 250 ohms.
Wiring	To make connections, perform the following procedure:
	1. Remove the housing cover on the side marked “FIELD TERMINALS.” Do
	not remove the cover in explosive atmospheres when the circuit is alive.
	All power to the transmitter is supplied over the signal wiring.
	2. Connect the lead that originates at the positive side of the power supply
	to the terminal marked “+” and the lead that originates from the negative
	side of the power supply to the terminal marked “–”. Avoid contact with
	the leads and terminals. Do not connect the powered signal wiring to the
	test terminals. Power could damage the test diode in the test connection.
	3. Plug and seal unused conduit connections on the transmitter housing to
	avoid moisture accumulation in the terminal side of the housing. If you do
	not seal the unused connections, mount the transmitter with the electrical
	housing positioned downward for drainage. Install wiring with a drip loop.
	Arrange the drip loop so the bottom is lower than the conduit connections
	and the transmitter housing.

	NOTE
	Signal wiring needs to be shielded, but use twisted pairs for best results. In
	order to ensure proper communication, use 24 AWG or larger wire, and do not
	exceed 5000 feet (1 500 meters).

	Do not use inductive-based transient protectors, including the Rosemount
	470, as they can adversely affect the output of Rosemount 3051N 4–20 mA
	transmitters.The Rosemount 3051N includes the transient protection terminal
	block (T1) as standard.
	Signal Wiring Grounding
	Do not run signal wiring in conduit or open trays with power wiring, or near
	heavy electrical equipment. You may ground the signal wiring at any one point
	on the signal loop, or leave it ungrounded. The negative terminal of the power
	supply is a recommended grounding point.

See “Safety Messages” on page 3-1for warning information.

3-13

Image 47

Contents Reference Manual Important Notice -- Errata Rosemount 3051N Return of Material Changes Changes from June 2006 to JuneOld Rosemount 3051N Table of Contents Specifications Reference Data InstallationTroubleshooting Hart Communicator OptionsAppendix a Glossary Index Section Introduction Using this ManualRosemount 3051N Transmitter Functions Overview Safety MessagesSecurity Alarm Level VerificationTransmitter Physical Removal Local Zero and Span Local Keys Configuring Transmitter Alarm and Security Jumper ProcedureElectronics Board Setting the Loop to Manual Wiring Diagrams Bench Hook-up Wiring Diagrams Field Hook-up Process Variables Review Configuration DataCheck Output Set Output Sensor TemperatureBasic Setup Set Process Variable UnitsRerange with a Communicator Only RerangeRerange with a Pressure Input Source and a Communicator Span and Zero Adjustment Buttons Diagnostics Service Detailed SetupCalibration Transmitter TestLoop Test Transmitter Bench Calibration Tasks Field Calibration Tasks Calibration Overview Configure the Analog Output ParametersURV Sensor TrimTypical Zero vs Non-zero-Based Application Illustrations Zero TrimDigital Trim Connection Drawing 4-20 mA Transmitters Full TrimAnalog Output Trim Digital-to-Analog Trim Using Other ScaleRecall Factory Trim Recall Factory Trim- Sensor Trim Recall Factory Trim- Analog OutputZero Effect HTc = URV + S URV Ps Rosemount 3051N Section Installation Rosemount 3051N Typical Installation Flowchart Mechanical Considerations General ConsiderationsSpecial Draft Range 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 Electrical Considerations Process Connections Housing RotationPower Supply Power Supply Load Limitations WiringEnvironmental Considerations Access Requirements Cover InstallationGrounding the Transmitter Case Troubleshooting Returning Rosemount Products and Materials Symptom Corrective ActionsSeismic Nuclear SpecificationsModel Range Code Hydrostatic Test Pressure Drift Performance SpecificationsAmbient Temperature Effect12 Reference AccuracyRange Code Static Pressure Zero Effect1 Power Supply Effect Load Effect Mounting Position EffectOverpressure Effect Static Pressure Effect Range Code Overpressure EffectOutput Functional SpecificationsService Temperature LimitsRange Code Minimum Time Constant Tc Including Dead Time Td Span and Zero, Zero Elevation, SuppressionRange Minimum Span Upper URL Lower LRL Overpressure Limits Burst Pressure Maximum WorkingPressure12 Static Pressure LimitsPhysical Specifications Materials of Construction Option Code Description Add Ordering Information Meters optional Configuration InformationHousing Material Conduit Entry Size Mounting Bracket OptionsDate On Rosemount 3051N Exploded View with Coplanar Process Flange Rosemount 3051N Rosemount 3051N Section Options Overview Safety Messages LCD MeterCustom Meter Configuration Exploded View of the Rosemount 3051N with Optional LCD Meter Installing the MeterRosemount 3051N Error Diagnostic MessagesPress Limit Mounting Brackets OperationTransient Protection Terminal Block T1 Traditional Flange H2Transient Protection Terminal Block T1 Rosemount 3051N Appendix a Hart Communicator Introduction Safety MessagesRosemount 3051N Online Menu Function Hart Fast Key Sequence Connections and Hardware Figure A-3. Rosemount Hart terminal access doorFigure A-4. Bench Hook-up MA Transmitters Action Keys RosemountCommunicator Keys Data Entry Function KeysAlphanumeric and Shift Keys Main Menu Fast Key SequencesFast Key Sequence Conventions Fast Key Sequence Example Menus FunctionsOnline Menu Touch Multifunction LED Processing Indication Alphanumeric KeysMultifunction LED Touch ScreenRosemount 3051N Message Description Diagnostic MessagesFast Key Sequences Hot Key options Rosemount 3051N Uploadvariable Rosemount 3051N Rosemount 3051N Glossary Smart Family Index 00809-0100-4808, Rev CA June Security Page ¢00809-0100-4801V¤