16
Reference Manual
00809-0100-4825, Rev CB
Section 2: Installation
March 2014
Installation
Figure 2-6. Rosemount 248 wiring
2.6.1
Sensor connections
The Rosemount 248 is compatible with a number of RTD and thermocouple sensor types.
shows the correct input connections to the sensor terminals on the transmitter. To
ensure proper sensor connection, anchor the sensor lead wires to the appropriate compression
terminals and tighten the screws. Use extreme caution when making contact with the leads and
terminals.
Figure 2-7. Sensor wiring Diagrams
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 input
connections with copper wire, and use shielding for long runs of wire.
Power, communication and
sensors terminals
Connecting a communicator to a transmitter loop
A. Field communicator
B. Power supply
C. 250
R
L
1100
Note: Signal loop may be grounded at any single point or left ungrounded.
Note: A Field Communicator may be connected at any termination point in the signal loop. The signal loop must have between 250 and
1100 ohms load for communications.
Rosemount 248 Sensor connections diagram
* 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.
44.0 (1.7)
33
12.9 (0.51)
24.5 (0.97)
C
B
A
1 2 3 4
2 3 4
1 2 3 4
1 2 3 4
1
2-wire
RTD and
3-wire*
RTD
and
T/C
and mV
4-wire RTD
and
