Honeywell STT850, STT750 Quick Start Guide

STT850/750 SmartLine Temperature Transmitter

Quick Start Guide

34-TT-25-04, Revision 9, November 2020

This document provides descriptions and procedures for the Quick Installation of Honeywell’s family of SmartLine Temperature Transmitters.

The SmartLine Temperature Transmitter is available in a variety of models for measuring Ohms, mV and temperature from RTD’s and thermocouples.

For full details refer to the manuals listed below for Protocols, User Interface (HMI) Operation, Installation, Configuration, Calibration, Maintenance, Parts, Safety and Approvals etc. including options.

Copyrights, Notices and Trademarks

Copyright 2020 by Honeywell Revision 9, November 2020

Trademarks

SFC, SmartLine, STT850 are U.S. registered trademarks of Honeywell Inc.

HART® and FOUNDATION™

Trademarks of FieldComm

Group™

Documentation

To access complete documentation, including language variants, scan the QR code below using your smart phone/device or QR code scanner.

Go to the APP store for your free Smartphone QR scanner

Or you can follow the URL to access the online SmartLine HUB page.

The HUB page will contain direct links to open SmartLine product documentation.

URL

QR Code

https://hwll.co/SmartLineHUB

Table of Contents
URL ...........................................................................................................	1
Note...........................................................................................................	1
Installation .................................................................................................	1
Features and options ................................................................................	1
Mounting the Transmitter ..........................................................................	1
Bracket Mounting ................................................................................	2
Optional Mounting Bracket .................................................................	2
Conduit Entry Plugs and Adapters............................................................	2
Wiring Connections and Power Up...........................................................	2
Wiring Variations.................................................................................	3
Input Sensor Wiring ............................................................................	3
Digital Output Wiring...........................................................................	4
Setting Failsafe Direction and Write Protect Jumpers........................	4
Write Protect Jumper on Foundation Fieldbus (FF) .................................	5
Figures
Figure 1 – Electronics Housing Components ...........................................	1
Figure 2 –STT with adapter housing - Horizontal Wall Mounting.............	1
Figure 3 - Pipe Mount, Vertical .................................................................	1
Figure 4 - Pipe Mount with adapter housing - Horizontal & Vertical.........	2
Figure 5: Flat and Angle Mounting Brackets secured to Horizontal or
Vertical Pipe ..............................................................................................	2
Figure 6: Electronic Housing Conduit Entries...........................................	2
Figure 7: HART and DE Transmitter Operating Ranges ..........................	2
Figure 8: Transmitter 9-Screw Terminal Board and Grounding Screw ....	3
Figure 9: HART/DE/FF Single Input Wiring Diagram ...............................	3
Figure 10: DE Dual Input Wiring Diagram ................................................	3
Figure 11: HART/FF – Dual Input Wiring Diagram ...................................	3
Figure 12: HART/FF Dual Input Wiring Diagram, mixed sensors ............	3
Figure 13: Digital Output Connections for mA Load (HART only)............	4
Figure 14: Digital Output Connections for PLC Counting Input (HART
only)...........................................................................................................	4
Figure 15: Jumper Location HART/DE .....................................................	4
Figure 16: Jumper Settings.......................................................................	4
Figure 17: Fieldbus Write Protect .............................................................	5

Note

This Quick Start Guide is for both STT850 and STT750 transmitters. Please note the following do not apply to the STT750: Foundation Fieldbus, DE, Dual Inputs, Advanced Display, Advanced Diagnostic, MID and Marine approvals.

Installation

Evaluate the site selected for the Transmitter installation with respect to the process system design specifications and Honeywell’s published performance characteristics for your particular model.

Temperature extremes can affect display quality. The display can become unreadable at temperature extremes; however, this is only a temporary condition. The display will again be readable when temperatures return to within operable limits.

The display will show power up message as "SmartLine Temperature Transmitter”. If there are any critical fault messages on the display, then refer to the STT850 Temperature transmitter user's manual (34-TT-25-03) document for recommended corrective actions and different screen formats

Features and options

The STT850 and STT750 are packaged in one major assembly: the Electronics Housing.

The elements in the Electronic Housing are connected to the process sensors, measure the process variables, respond to setup commands and execute the software and protocol for the different temperature measurement types. Figure 1 shows the assemblies in the Electronics Housing with available options.

Mounting the Transmitter

Transmitter models can be attached to a two-inch (50 millimeter) vertical or horizontal pipe using Honeywell’s optional angle; alternately you can use your own bracket.

Honeywell’s optional wall mounting bracket is also shown below:

For Housing with Adaptor refer to Honeywell drawings 50095917 (Pipe mount) and 50095918 (Wall mount) for detailed mounting specifications.

For Housing without adaptor refer to Honeywell drawings 32306827 (No-Adaptor, Pipe mount) and 32306828 (No-adaptor, Wall mount).

TRANSMITTER ENCLOSURE CAN BE ROTATED A TOTAL OF 90O FROM THE STANDARD MOUNTING POSITION

Figure 2 –STT with adapter housing - Horizontal Wall Mounting

Figure 1 – Electronics Housing Components
An optional 3-button assembly is located under the nameplate and provides a user
interface and operation capability without opening the transmitter to set up and make
adjustments to the transmitter.	Figure 3 - Pipe Mount, Vertical

STT850/750 Quick Start Guide

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			Optional Mounting Bracket
			Position bracket on 2-inch (50.8 mm) and install “U” bolt around pipe and through holes
			in bracket. Secure with nuts and lock washers provided. Optional mounting bracket, see
			Figure 5
				HORIZONTAL FLAT PIPE	VERTICAL FLAT PIPE
Figure 4 - Pipe Mount with adapter housing - Horizontal & Vertical
Bracket Mounting
If you are using an optional bracket, start with Step 1.
1.	Align the two mounting holes in the transmitter with the two slots			HORIZONTAL ANGLE PIPE	VERTICAL ANGLE PIPE
	in the mounting bracket and assemble the (2) M8 hex cap
	screws, (2) lockwashers and (2) flat washers provided. Rotate			Figure 5: Flat and Angle Mounting Brackets secured to Horizontal or Vertical Pipe
	transmitter assembly to the desired position and torque the M8
	hex cap screws to 27,0 Nm/20,0 Lb-ft maximum.
2.	Pipe Mount Option: Refer to Figure 5. Position the bracket on a 2-
	inch (50.8 mm) horizontal or vertical pipe, and install a “U” bolt
	around the pipe and through the holes in the bracket. Secure the
	bracket with the nuts, flat washers and lock washers provided.
3.	Wall Mount Option: Position the bracket on the mounting surface
	at the desired location and secure the bracket to the mounting
	surface using the appropriate hardware (Wall mounting hardware
	requirements to be determined and supplied by the end user).
	Existing mounting bracket, see Figure 5
Conduit Entry Plugs and Adapters			Wiring Connections and Power Up
Procedures			Summary
It is the User/Installer’s responsibility to install the Transmitters in accordance			The transmitter is designed to operate in a two-wire power/current loop with
with national and local code requirements. Conduit entry plugs and adapters			loop resistance and power supply voltage within the HART and DE
shall be suitable for the environment, shall be certified for the hazardous			operating ranges shown in Figure 7.
location when required and acceptable to the authority having jurisdiction for
the plant.
CONDUIT ENTRY PRECAUTIONARY NOTICE
THE CONDUIT/CABLE GLAND ENTRIES OF THIS PRODUCT ARE
SUPPLIED WITH PLASTIC DUST CAPS WHICH ARE NOT TO BE USED IN
SERVICE.
IT IS THE USER’S RESPONSIBILITY TO REPLACE THE DUST CAPS
WITH CABLE GLANDS, ADAPTORS AND/OR BLANKING PLUGS WHICH
ARE SUITABLE FOR THE ENVIRONMENT INTO WHICH THIS PRODUCT
WILL BE INSTALLED. THIS INCLUDES ENSURING COMPLIANCE WITH
HAZARDOUS LOCATION REQUIREMENTS AND REQUIREMENTS OF
OTHER GOVERNING AUTHORITIES AS APPLICABLE.
				Figure 7: HART* and DE Transmitter Operating Ranges
			*Only HART available for STT750 transmitter
			For DE operation, add 3.0V to these values.
			Loop wiring is connected to the Transmitter by simply attaching the positive
			(+) and negative (–) loop wires to the positive (+) and negative (–) terminals
			on the transmitter terminal block in the Electronics Housing, shown in
			Figure 8.
			Grounding Details:
	Figure 6: Electronic Housing Conduit Entries		Connect the Loop Power wiring shield to earth ground only at the power
			supply end.
Note. No plugs come installed in the housings. All housings come with			Note: The transmitter is not polarity-sensitive.
temporary plastic dust protectors (red) installed and are not certified for use
in any installation.

STT850/750 Quick Start Guide

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Figure 8: Transmitter 9-Screw Terminal Board and Grounding Screw

As shown in Figure 8, each Transmitter has an internal terminal to connect it to earth ground. Connect sensor shield to the internal ground screw. The ground terminal can be added to the outside of the Electronics Housing. Grounding the Transmitter for proper operation is required, as 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 areas that are highly susceptible to lightning strikes. As noted above, the Loop Power wiring shield should only be connected to earth ground at the power supply end.

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: Terminal #3 is for loop test and is not applicable for Fieldbus option. Terminal #4 is for Digital Output and is not applicable for Fieldbus option. Foundation Fieldbus not applicable to STT750

For HART and DE 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 7 With an optional remote meter, the voltage drop for this must be added to the basic power supply voltage requirements to determine the required Transmitter voltage and maximum loop resistance. Additional consideration is required when selecting intrinsic safety barriers to ensure that they will supply at least minimum Transmitter voltage, including the required 250 ohms of resistance (typically within the barriers) needed for digital communications.

Figure 10: DE Dual Input Wiring Diagram

•Resistance temperature detector (RTD) measurements use the 3 or 4 wire approach.

•Dual-input units wired for a 4-wire RTD will automatically disable Input 2.

•DE dual input device needs to be power cycled whenever sensor input wiring changed

•Supports dual thermocouple or RTD inputs for differential temperature measurement

•Supports dual thermocouple sensor inputs for redundant sensor operation.

•To operate DE dual input device, it is required to connect both sensor inputs

•To minimize common noise problems in the application, a strap/jumper should be wired between terminals 6 and 8.

For differential T/C operation on DE Models, a second strap/jumper should be wired between terminals 6 and 7. Do not install this strap for Non-DE models. The output for differential operation is calculated as T/C 1 - T/C 2.

Figure 10: DE Dual Input Wiring Diagram

Thermocouple and RTD Connections (not applicable to single input sensor)

DE not applicable to STT750 transmitter

Wiring Variations

The above procedures are used to connect power to a Transmitter. For loop 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. This procedure shows the steps for connecting power to the transmitter.

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 the SmartLine Transmitter User’s Manual 34-TT-25-03 (STT850) or 34-TT-25-13 (STT750) for details.

NOTE: After wiring, torque the screws to around 4 to 5(lb-in). Maximum should not exceed 1.1 Nm (10 lb-in). Don’t pull the wires after connecting to the screw terminals.

Input Sensor Wiring

Connect the input sensors as shown in Figures below:

Figure 9: HART/DE/FF Single Input Wiring Diagram. *Only HART available for STT750 transmitter

Figure 9: HART*/DE/FF Single Input Wiring Diagram

RTD Thermocouple, mV and Ohm Connections

Figure 11: HART/FF – Dual Input Wiring Diagram

RTD Thermocouple, mV and Ohm Connections

Figure 12: HART/FF Dual Input Wiring Diagram

•For External C/J compensation, the first input is a thermocouple type and the second input is a 3-wire PT100 ohm RTD

•The STT850 can have different sensor types on its inputs for split range or averaging applications

Figure 12: HART/FF Dual Input Wiring Diagram, mixed sensors

Remote C/J and Mixed Sensors Connections

STT850/750 Quick Start Guide

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