Emerson Rosemount 3144P Reference Manual page 26

Rosemount 3144P
Figure 2-10. m Connecting
a Communicator to a
Transmitter Loop (HART/ 4–20
mA).
2-12
Power/Current Loop Connections
Use copper wire of a sufficient size to ensure that the voltage across the
transmitter power terminals does not go below 12.0 V dc.
1. Connect the current signal leads as shown in Figure 2-10.
2. Recheck the polarity and correctness of connections.
3. Turn the power ON.
For information about multichannel installations, refer to page 2-17.
NOTE
Do not connect the power/signal wiring to the test terminal. The voltage
present on the power/signal leads may burn out the reverse-polarity
protection diode that is built into the test terminal. If the test terminal's reverse
polarity protection diode is burned out by the incorrect power/signal wiring, the
transmitter can still be operated by jumping the current from the test terminal
to the "–" terminal. See "Test Terminal" on page 4-3 for use of the terminal.
Power/Signal Terminals
AMS software or a 375 Field Communicator can be connected at any termination
point in the signal loop. The signal loop must have between 250 and 1100 ohms
load for communications.
The signal wire may be grounded at
any point or left ungrounded.
≤ ≤
250 R 1100
L
or*
Reference Manual
00809-0100-4021, Rev EA
March 2007
Power
Supply