TCX 126
Two-Wire Isolated Thermocouple Transmitter
Instruction Manual
1.0 INTRODUCTION
These instructions refer to the above model. Supplementary
sheets are attached if the unit has special options or features.
For detailed specifications, see page 4 or refer to the Data
Bulletin. All ADTECH instruments are factory calibrated and
supplied with a label detailing the calibration. Adjustments are
normally not necessary. A simple calibration should be
performed to verify calibration before installation.
2.0 GENERAL DESCRIPTION
The ADTECH Model TCX 126 Isolated Two-Wire
Thermocouple Transmitter provides high accuracy conversion
of ISA type J, K, T, E, R, S and B thermocouples and mv to a
standard 4-20 ma de process signal.
The TCX 126 provides 350 volts ac or 600 volts de isolation
from the input to outpuVpower supply.
The primary features of the TCX 126 are:
• Wide range - covers the full range of ISA standard
thermocouples and mv.
• Field adjustable via front accessible switches and
potentiometers.
• Zero suppression of up to 100% of the major range with
a16 position switch.
• High accuracy, repeatability, and ambient temperature
effect stability.
• RFI Protection: Standard.
• NO INTERACTION of zero and span controls.
• Small size - universal mounting package provides
integral RFI protection and an environmental seal.
• Options for NEMA 4 and NEMA 7 housings, SNAP
TRAK and DIN rail mounting (DIN 46 277 standard).
3.0 INSTALLATION
The instrument is supplied in a sturdy die cast aluminum
housing with an epoxy paint finish. The housing is gasketed
providing an environmental seal for the internal electronics
and controls. NEMA 4, NEMA 7 and 12, Snap Track and DIN
rail (TS32 and TS35) are optionally available. Installation
area I location must agree with the supplied instruments
including operating temperature and ambient conditions.
Mounting
Refer to page 3 for outline and mounting dimensions. The
standard instrument is surface mounted with integral #6-32
S.S. thumb screws.
Electrical Connections
The
wire
used to connect the instrument to the control system
Input/ Output
should be twisted pair(s) and sized according
to normal practice. Shielded cable is not normally necessary
(if used, the shield must be grounded at the negative input of
the ADTECH instrument and left floating at the sensor).
Two barrier terminal blocks with #6-32 screws and 0.325"
spacing are provided for I/ 0 connections.
Controls
Instrument controls consist of the following:
• Two 16 position switches for
COARSE
ZERO and SPAN
control.
• One 8 position dip switch for selection of thermocouple
and major range.
• Two multiturn potentiometers;
FINE
ZERO and SPAN
controls.
All controls are accessible through the front of the instrument.
An integral gasketed cover provides an environmental seal for
the controls and internal electronics when the controls are not
in use.
4.0 MAINTENANCE
These instruments are electronic and require no maintenance
except periodic cleaning and calibration verification. If the unit
appears to be mis-operating, it should be checked as installed
per section 6.0 or removed for a bench check per sections 6.0
and 7.0. MOST problems are traced to field wiring and/ or
associated circuits. If the problem appears to be with the
instrument, proceed to sections 6.0 and 7.0.
5.0 CONNECTIONS
Standard connections are shown below and on the instrument
face plate, Data Bulletin or on attached supplementary sheets.
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NOTE 1: Terminal #3 should not have any customer
connections.
NOTE 2: Intrinsically safe when connected per Installation
DWG 270-A-000003.
-1-
190-A-000051-8
