Instruction Manual

IB-106-3081 Rev. 1.5 September 2002

Model 3081FG

pairs are recommended. Ground the trans- mitter housing to an earth ground to prevent unwanted electromagnetic interference (EMI) or radio frequency interference (RFI).

NOTE

For optimum EMI/RFI immunity, shield the 4-20 mA current loop cable and enclose in an earth grounded metal conduit.

NOTE

Never run signal or sensor wiring in the same conduit, or open tray, with power cables. Keep signal or sensor wiring at least 12 in. (0.3 m) away from other electrical equipment and 6.5 ft (2 m) from heavy electrical equipment.

It is necessary to prevent moisture from entering the Model 3081 Transmitter hous- ing. The use of weather-tight cable glands is required. If conduit is used, plug and seal connections on the transmitter housing to prevent moisture accumulation in the termi- nal side of the housing.

Moisture accumulation in the transmit- ter housing can affect its performance and may void its warranty.

b.Oxygen Probe Signal Connections

1.Two signals represent the O2 value and the cell temperature. The probe pro- vides these values to the Model 3081 Transmitter for processing and signal conditioning.

2.Wiring connections for the probe are shown in Figure 2-9.

c.Model 3081 Transmitter 4-20 mA and Signal Connections

1.A 4-20 mA signal represents the O2 value. Superimposed on the 4-20 mA

signal is HART information that is ac- cessible through a Model 275 Hand- held Communicator or AMS software.

2.Two signals representing the O2 value and the cell temperature are supplied to the Model 3081 Transmitter from the oxygen probe.

3.Wiring connections for the Model 3081 Transmitter are shown in Figure 2-10.

NOTE

The ground arrangement shown in Figure 2-10limits the amount of noise introduced into the electronics.

4.Connect wire shields to terminal 1. Connect earth ground as shown.

TERMINAL

BLOCK

 

 

 

 

 

 

 

CONDUIT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+(GY)

-(RD)

 

 

 

 

THERMOCOUPLE

THERMOCOUPLE

 

 

 

 

CELL-(WH)

CELL+(BK)

 

 

 

 

 

 

26020004

Figure 2-9. Oxygen Probe Terminal Block

2-10 Installation

Rosemount Analytical Inc. A Division of Emerson Process Management

Page 28
Image 28
Emerson 3081FG Model 3081 Transmitter 4-20 mA and Signal Connections, Terminal Block Conduit, Thermocouple CELL-WH CELL+BK