Emerson 644 manual Sensor Connections, Thermocouple or Millivolt Inputs

Rosemount 644

Figure 2-6. Connecting a

FOUNDATION fieldbus Host

System to a Transmitter Loop

Integrated Power

Conditioner and Filter

Reference Manual

00809-0400-4728, Rev AA

June 2011

6234 ft (1900 m) max

(depending upon cable characteristics)

Terminators

Power

Supply

(The power supply,

filter, first

terminator, and

configuration

tool are typically

located in the control room.)

(Trunk)

(Spur)

FOUNDATION

fieldbus

Configuration

Tool

(Spur)
	Power/
Devices 1	Signal
through 16	Wiring

Sensor Connections

Figure 2-7. Sensor Wiring Diagrams

The 644 is compatible with a number of RTD and thermocouple sensor types. Figure 2-7shows the correct input connections to the sensor terminals on the transmitter. To ensure a proper sensor connection, anchor the sensor lead wires into the appropriate compression terminals and tighten the screws.

644 Sensor Connections Diagram

1 2 3 4	1 2 3 4	1 2 3 4	1 2 3 4
2-wire	3-wire RTD*	4-wire RTD	T/C
RTD and	and	and	and mV

*Emerson Process Management provides 4-wire sensors for all single element RTDs. Use these

RTDs in 3-wire configurations by leaving the unneeded leads disconnected and insulated with electrical tape.

Thermocouple or Millivolt Inputs

The thermocouple can be connected directly to the transmitter. Use appropriate thermocouple extension wire if mounting the transmitter remotely from the sensor. Make millivolt inputs connections with copper wire. Use shielding for long runs of wire.

2-8