Omega Products TX91A Installation Manual

User’s Guide

Shop online at

Mini

e-mail: [e-mail]

omega.com

For latest product manuals:

omegamanual.info

TX91A (J, K, T, E)

4-20 mA

Temperature Transmitter

OMEGAnet®Online Service Internet e-mail

omega.com [e-mail]

Servicing North America:

U.S.A.: One Omega Drive, P.O. Box 4047

ISO 9001 Certified Stamford, CT 06907-0047

Canada: 976 Bergar

For immediate technical or application assistance:

U.S.A. and Canada: Sales Service: 1-800-826-6342/1-800-TC-OMEGA

Mexico: En Espan˜ ol: [phone]-7803

TEL: [phone]
FAX: [phone]
e-mail: [e-mail]

Laval (Quebec) H7L 5A1, Canad
TEL: [phone]
FAX: [phone]
e-mail: info@omega.c

Customer Service: 1-800-622-2378/1-800-622-BEST
Engineering Service: 1-800-872-9436/1-800-USA-WHEN

e-mail: [e-mail]
FAX: [phone]
[e-mail].m

a

a

®

®

x

®

Servicing Europe:

Czech Republic: Frystatska 184, 733 01 Karviná, Czech Republic

Germany/Austria: Daimlerstrasse 26, D-75392 Deckenpfronn, Germany

United Kingdom: One Omega Drive, River Bend Technology Centre

ISO 9001 Certified Northbank, Irlam, Manchester

It is the policy of OMEGA Engineering, Inc. to comply with all worldwide safety and EMC/EMI
regulations that apply. OMEGA is constantly pursuing certification of its products to the European
New Approach Directives. OMEGA will add the CE mark to every appropriate device upon certification.

The information contained in this document is believed to be correct, but OMEGA accepts no liability for
any errors it contains, and reserves the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, human applications.

This device is marked with the international caution symbol. It is important to read the Setup
Guide before installing
relating

to safety and EMC.

TEL: [phone]
FAX: [phone]

Toll Free: 0800-1-66342
e-mail: [e-mail]

TEL: [phone]­FAX: [phone]
Toll Free in Germany: 0800 639 7678
e-mail: info@omega.d

M44 5BD United Kingdom
TEL: [phone]
FAX: [phone]
Toll Free in United Kingdom: 0800-488-488
e-mail: [e-mail]

or commissioning this device as it contains important information

0

e

i

TTAABBLLEE OOFF CCOONNTTEENNTTSS PPAAGGEE

1.0 GETTING STARTED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Unpacking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Safety and EMC Considerations . . . . . . . . . . . . . . . . . . . . 1

1.3 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.4 Available Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.5 Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.6 Shock Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.0 CONNECTING POWER AND SIGNAL INPUTS. . . . . . . . . 4

3.0 CALIBRATING THE TRANSMITTER. . . . . . . . . . . . . . . . . 6

4.0 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

LIST OF FIGURES AND TABLES

Figure 2-1 Power Input Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 2-2 Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3-1 Calibration Setup using a Millivolt Source . . . . . . . . . . . . . 6

Figure 3-2 Calibration using a Thermocouple Simulator . . . . . . . . . . . 7

Figure 4-1 Case Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 4-2 Transmitter Block Diagram . . . . . . . . . . . . . . . . . . . . . . . 11

Table 1-1 Range/Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Table 2-1 Screw-Terminal Pin Assignment . . . . . . . . . . . . . . . . . . . . 5

Table 3-1 Fahrenheit Temperature to Millivolt Conversion Chart . . . . 8

Table 3-2 Celsius Temperature to Millivolt Conversion Chart . . . . . . . 9

ii

SECTION 1 GETTING STARTED

1.1 Unpacking

Remove the packing list and verify that you have received all equipment. If you have
any questions, contact the nearest Customer Service Department, as listed on the
cover of this manual.

Upon receipt of shipment, inspect the container and equipment for any signs of
damage. Note any evidence of rough handling in transit. Immediately report any
damage to the shipping agent.

Note: The carrier will not honor any claims unless all shipping material is saved for
their examination. After examining and removing contents, save packing materials
and carton in the event reshipment is necessary.

1.2 Safety and EMC Considerations

This instrument is a Class III device (8 to 50 Vdc).
Always use a power supply, which complies with EN 60950 safety standard.

••

Do not expose the transmitter to rain or condensing moisture.

••

Do not operate the transmitter in flammable or explosive atmosphere.

••

As with any electronic instrument, you may encounter high voltage exposure
when installing, calibrating or removing parts of the transmitter.

EMC Considerations

••

Whenever EMC is an issue, always use shielded cables.

••

Never run signal and power wires in the same conduit.

••

Use signal wire connections with twisted-pair cables.

••

Install Ferrite Bead(s) on signal wires close to the instrument if EMC problems
persist.

Failure to follow all instructions and warnings may result in injury!

1.3 General Description

The TX91A Series transmitter accepts thermocouple sensor types J, K, T, and E and
will produce a standard 4-20 mA output signal proportional to that produced by its
attached thermocouple millivolt input. The transmitter does NOT provide isolation
between its input and the 4-20 mA output; therefore, an ungrounded thermocouple
junction is suggested to prevent possible ground loops.

The transmitter provides cold reference junction compensation for the thermocouple
types as well as amplification, common-mode rejection and controlling the current
drawn from an 8-to-50 Vdc source to produce the 4-to-20 mA output signal. As
much as 800 ohms dropping resistance may be used in the power leads of the
TX91A when the unit is energized from a 24 Vdc source because of the small
compliance voltage needed by the unit.

1

1.4 Available Ranges

As specified in Table 1-1, the transmitter has 10 ranges. Depending upon the range,
the transmitter can measure temperature span as narrow as 160°F or as wide as
1000°F. A multi-turn, top-accessible potentiometer provides fine span tuning. A
second top-accessible, multi-turn potentiometer provides a zero adjustment which
allows placement of the 4-mA output temperature within +/- 25% for Fahrenheit and
+/- 10% for Celsius of nominal span (refer to Section 3.0, Calibrating the Transmitter,
for more details).

Table 1-1. Range/Models

RRaannggee MMooddeell

0 to 200°FJ2K2T2E2
0 to 300°FJ3K3T3E3
0 to 500°FJ4K4T4E4
0 to 750°FJ5K5T5E5

0 to 1000°F J6 K6 N/A E6

-0 to 100°CJ7K7T7E7

-0 to 150°CJ8K8T8E8

-0 to 250°CJ9K9T9E9

-0 to 400°C J10 K10 T10 E10

-0 to 500°C J11 K11 N/A E11

2