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As shown in Figure 15, each Transmitter has an internal terminal to connect it to earth ground.
Optionally, a ground terminal can be added to the outside of the Electronics Housing. While it is not
necessary to ground the Transmitter for proper operation, doing so tends to minimize the possible
effects of noise on the output signal and affords protection against lightning and static discharge. An
optional lightning terminal block can be installed in place of the non-lightning terminal block for
Transmitters that will be installed in an area that is highly susceptible to lightning strikes.
Wiring must comply with local codes, regulations and ordinances. Grounding may be
required to meet various approval body certification, for example CE conformity. Refer to
Appendix A of this document for details.
Note: The right hand terminal is for loop test and not applicable for Fieldbus option.
The Transmitter is designed to operate in a two-wire power/current loop with loop resistance and
power supply voltage within the operating range; see Figure 14. With optional lightning protection
and/or a remote meter, the voltage drop for these options must be added to the basic 10.8-volt supply
requirements to determine the required Transmitter voltage (V
(R
). Additional consideration is required when selecting intrinsic safety barriers to ensure that
LOOP MAX
they will supply at least minimum Transmitter voltage (V
of resistance (typically within the barriers) needed for digital communications.
Transmitter loop parameters are as follows:
R
= maximum loop resistance (barriers plus wiring) that will allow proper Transmitter
LOOP MAX
operation and is calculated as R
In this calculation:
V
= 10.8 V + V
XMTR MIN
V
= 2.3 V, remote meter
SM
Note that V
should only be considered if a remote meter will be connected to the transmitter.
SM
The positive and negative loop wires are connected to the positive (+) and negative (–) terminals on
the terminal block in the Transmitter Electronics Housing.
Barriers can be installed per Honeywell's instructions for Transmitters to be used in intrinsically safe
applications.
3.6.2 Digital System Integration Information
Transmitters that are to be digitally integrated to Honeywell's Total Plant Solution (TPS) system will
be connected to the Pressure Transmitter Interface Module in the Process Manager, Advanced
Process Manager or High Performance Process Manager through a Field Termination Assembly.
Details about the TPS system connections are given in the PM/APM SmartLine Transmitter
Integration Manual, PM12-410, which is part of the TDC 3000
If you are digitally integrating a Transmitter in an Allen Bradley Programmable Logic Controller
(PLC) process system, the same Field Terminal Assembly (FTA) and wiring procedures used with
Honeywell's TPS system are also used with the Allen-Bradley 1771 and 1746 platforms.
Revision 10
= (V
LOOP MAX
+ V
LP
SM
ST 800 SmartLine Pressure Transmitters User's Manual
) and maximum loop resistance
XMTR
), including the required 250 ohms
XMTR MIN
) 21.8 mA.
– V
SUPPLY MIN
XMTR MIN
X
system bookset.
Page 21
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