Transient Protection Terminal Block - Emerson Rosemount 3051 Reference Manual

Installation
May 2017
3. Ensure full contact with Terminal Block screw and washer. When using a direct wiring method, wrap
wire clockwise to ensure it is in place when tightening the terminal block screw.
Note
The use of a pin or ferrule wire terminal is not recommended as the connection may be more susceptible
to loosening over time or under vibration.
4. Plug and seal unused conduit connection on the transmitter housing to avoid moisture accumulation
in the terminal side. Install wiring with a drip loop. Arrange the drip loop so the bottom is lower than
the conduit connections and the transmitter housing.
Power supply for 4-20 mA HART
Transmitter operates on 10.5 –42.4 Vdc. The dc power supply should provide power with less than two
percent ripple.
Note
A minimum loop resistance of 250 ohms is required to communicate with a Field Communicator. If a
single power supply is used to power more than one Rosemount 3051 Transmitter, the power supply
used, and circuitry common to the transmitters, should not have more than 20 ohms of impedance at
1200 Hz.
Figure 3-17. Load Limitation
Maximum loop resistance = 43.5 * (Power supply voltage – 10.5)
1387
1000
500
The Field Communicator requires a minimum loop resistance of 250Ω for communication.
The total resistance load is the sum of the resistance of the signal leads and the load resistance of the
controller, indicator, and related pieces. Note that the resistance of intrinsic safety barriers, if used, must
be included.
Power supply for 1–5 Vdc HART low power
Low power transmitters operate on 6–14 Vdc. The dc power supply should provide power with less than
two percent ripple. The V
3.9.3

Transient protection terminal block

The transmitter will withstand electrical transients of the energy level usually encountered in static
discharges or induced switching transients. However, high-energy transients, such as those induced in
wiring from nearby lightning strikes, can damage the transmitter.
48
Operating
Region
0
10.5 20 30
42.4
Voltage (Vdc)
load should be 100 k
out
Ω or greater.
Reference Manual
00809-0100-4001, Rev KA
Installation