Power Supply; Wiring The Transmitter - Emerson Rosemount 2051 Reference Manual

Reference Manual
00809-0100-4107, Rev BA
4.6.2

Power supply

4-20 mA HART (option code A)
Transmitter operates on 10.5-42.4 Vdc at the terminal of the transmitter. The dc power supply
should provide power with less than two percent ripple. A minimum of 16.6V is required for
loops with a 250  resistance.
Note
A minimum loop resistance of 250 s is required to communicate with a Field Communicator. If
a single power supply is used to power more than one Rosemount 2051 transmitter, the power
supply used, and circuitry common to the transmitters, should not have more that 20 s of
impedance at 1200 Hz.
Figure 4-5. Load limitation
The Field Communicator requires a minimum loop resistance of 250
The total resistance load is the sum of the resistance of the signal leads and the load resistance
of the controller, indicator, I.S. Barriers, and related pieces. If intrinsic safety barriers are used,
the resistance and voltage drop must be included.
1-5 Vdc Low Power HART (output code M)
Low power transmitters operate on 9-28 Vdc. The dc power supply should provide power with
less than 2 percent ripple. The V
4.6.3

Wiring the transmitter

Do not connect the power signal wiring to the test terminals. Incorrect wiring can damage
test circuit.
Note
Use shielded twisted pairs to yield best results. To ensure proper communication, use 24 AWG
or larger wire and do not exceed 5000 feet (1500 meters). For 1-5V 500 feet (150meters)
maximum are recommended. unpaired three conductor or two twisted pairs is recommended.
Electrical Installation
Maximum Loop Resistance = 43.5 * (Power Supply Voltage – 10.5)
1387
1000
500
0
10.5
out
Operating
Region
20 30
42.4
Voltage (Vdc)

for communication.
load should be 100 k or greater.
Section 4: Electrical Installation
April 2013
59