Emerson 1154, 00809-0100-4514 manual Transmitter Wiring Connections

Page 17

Reference Manual

00809-0100-4514, Rev BA January 2008

Rosemount 1154

Figure 2-2. Transmitter Wiring Connections.

Figure 2-3. Supply Voltage vs. Load.

Signal wiring need not be shielded, but twisted pairs yield the best results. In electrically noisy environments, shielded cable should be used for best results. Do not run signal wiring in conduit or open trays with power wiring, or near heavy electrical equipment. Signal wiring may be ungrounded (floating) or grounded at any place in the signal loop. The transmitter case may be grounded or ungrounded.

The capacitance-sensing element uses alternating current to generate a capacitance signal. This alternating current is developed in an oscillator circuit with a frequency of 32,000 ±10,000 Hz. This 32,000 Hz signal is capacitor coupled to transmitter case ground through the sensing element. Because of this coupling, a voltage may be imposed across the load, depending on choice of grounding.

The impressed voltage, which is seen as high frequency noise, has no effect on most instruments. Computers with short sampling times in a circuit where the negative transmitter terminal is grounded will detect a significant noise signal. Filter this noise with a large capacitor (1 µf) or by using a 32,000 Hz LC filter across the load. Signal loops grounded at any other point are negligibly affected by this noise and do not need filtering.

Power

Supply

Terminal Side

Cover Removed

4—20 mA DC

	1825			Qualified
1575				Qualified
1575	1500			Region
	1500			Region
(Ω)	1000
Resistance	1000
				Design
	500			Region

Load	0
Load	0		40	50
	0	12	35	45
		12	35	45

13.5Power Supply (V DC)

2-5

Image 17

Contents Reference Manual RosemountImportant Notice -- Errata Rosemount 1154 Alphaline Nuclear Pressure Transmitter Return of Material New Old Changes Revision StatusChanges From June 1999 to January Rosemount Table of Contents Section Maintenance TroubleshootingSpecifications Reference Data TOC-3 TOC-4 Overview About the Transmitter Section IntroductionRosemount Overview General Considerations Section InstallationProcess Connections Mechanical ConsiderationsRosemount Electrical Considerations ConduitTransmitter Wiring Connections Mechanical InstallationProcedures Range Code Pressure DimensionElectrical Liquid ServiceTransmitter Terminal Block Rosemount Overview Calibration Span Adjustment Zero AdjustmentSection Calibration Zero and Span Adjustment Calibration ProceduresZero and Span Adjustment Screws Linearity Adjustment Linearity and Damping Adjustment Damping AdjustmentRosemount Calculate zero adjustment correction in terms of pressure Rosemount Overview Transmitter Operation Section OperationΔ-Cell Demodulator Linearity AdjustmentFV Iref Overview Maintenance TroubleshootingTest Terminals Board Checkout Safety MessagesSensing Module Checkout Process Flange Removal Disassembly ProcedurePart Description Rosemount 1154 Parts ListReassembly Procedure Rosemount Process Flange Reassembly On Next Post Assembly TestsSymptom Potential Source Corrective Action Check for adequate voltage to the transmitter Nuclear Specifications Specifications and Reference DataPerformance Specifications Range Code Overpressure Effect Range Code Response Time Functional SpecificationsRange Code Static Pressure Zero Effect 25 to 0-150 inH2O 0-6.22 to 0-37.3 kPa Range Code Pressure RangesRange Code Overpressure Limit Physical SpecificationsRosemount Ordering Information Rosemount 1154DP 1154HP 1154GP Part Description Order No Rosemount 1154DP, 1154HP, and 1154GP Spare PartsFor use with existing N0026 transmitter only Spare Parts Shelf Life Important Notice Rosemount Current Control Current Limit Index-2 Page ¢00809-XXXX-XXXX ¤