Emerson Rosemount 3051 Reference Manual page 77

Reference Manual
00809-0100-4007
4.6.2 Power supply for a 4-20 mA HART
The transmitter operates on 10.5-4.2 Vdc at the terminal of the transmitter. The dc power
supply should provide power with less than two percent ripple. Loops with a 250 Ω
resistance require a minimum of 16.6 V.
Note
The transmitter must have a minimum of 250 Ω to communicate with a Field
Communicator. If you are using a single power supply to power more than one Rosemount
3051 Transmitter, make sure the power supply used and the circuitry common to the
transmitters do not have more than 20 Ω of impedance at 1200 Hz.
Figure 4-5: Load Limitation
Maximum loop resistance = 43.5 x (power supply voltage - 10.5)
A. Load (Ωs)
B. Voltage (Vdc)
C. Operating region
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 you use intrinsic
safety barriers, make sure to include the resistance and voltage drop.
4.6.3 Wire the transmitter
CAUTION
Equipment damage
Incorrect wiring can damage test circuit.
Do not connect the power signal wiring to the test terminals.
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).
Reference Manual
Electrical installation
®
August 2019
77