Wiring Variations; Loop Wiring Procedure - Honeywell STT750 SmartLine User Manual

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 = 11.8 V (HART) V
XMTR MIN
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.

3.5.2. Wiring Variations

The above procedures are used to connect power to a Transmitter. For loop wiring, sensor wiring and
external wiring, detailed drawings are provided for Transmitter installation in non-intrinsically safe
areas and for intrinsically safe loops in hazardous area locations.

3.5.3. Loop Wiring Procedure

1. See Figure 12,
2. Remove the end cap cover from the terminal block end of the Electronics Housing.
3. Feed loop power leads through one end of the conduit entrances on either side of the
Electronics Housing. The Transmitter accepts up to 16 AWG wire.
4. Connect the positive loop power lead to the positive (+) terminal #1 and the negative loop
power lead to the negative (-) terminal #2. Note that the Transmitter is not polarity-sensitive.
5. Feed sensor input wires through the second housing conduit entry and connect wires per
Figure 12.
6. Replace the end cap, and secure it in place.
Revision 4
= (V
LOOP MAX SUPPLY MIN
= 2.3 V, remote meter
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above, for parts locations. Loosen the end cap lock using a 1.5 mm Allen wrench.
STT750 Temperature Transmitter User's Manual
)  21.8 mA.
– V
- V
XMTR MIN SM
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