The 1734-TBCJC is a Cold Junction Compensation (CJC) module wiring base assembly. This unit is part of the 1734 POINT I/O system from Allen-Bradley and exclusively paired with the POINTI/O Thermocouple module with catalog number 1734-IT2I. Being a wiring base assembly, the 1734-TBCJC is composed of a removable terminal block and the wiring base. It also has an easy to identify mechanical keying, RTB removable handle, interlocking side pieces, and DIN rail locking screw. The 1734-TBCJC terminal assignment includes 0+ and 0- which are terminals 4 and 5 respectively; 1+ and 1- which are terminals 6 and 7 respectively while shield connection is made via terminal no. 3. Terminals 0, 1, and 2 do not require any connection. To install this wiring base assembly, it must be positioned vertically above the adapter, power supply, or existing module. Slide the unit down and align the interlocking side pieces and engage to the adjacent partner module. Press the wiring base against the DIN rail until the unit snaps into place. To uninstall the wiring base, the hosted module must be uninstalled first then a flat blade screwdriver must be used to disengage the interlocking mechanism. The 1734-TBCJC has a supply voltage of 28.8V DC, 120/240V AC; maximum supply current of 10 Amperes; physical dimension of 65 x 12 x 133.4 mm (2.56 x 0.472 x 5.25 in.) and wire size of 0.25…2.5 mm2 (24…14 AWG) and thermocouple wire of 1.2 mm (3/64 in.), maximum insulation. It approximate weighs 97.5 g or (3.44 oz).

The 1734-TBCJC is a POINT I/O Cold Junction Compensation Wiring Base Assembly by Allen Bradley, which includes a Removable Terminal Block (RTB) and eight (8) separate terminal locations for wiring. This product is made exclusively for use with 1734-IT2I Thermocouple Input Module.

Mounted on a base that is mounted on a DIN-rail, the RTB can vertically access screw terminations and wires, with each wire having a different terminal point available, which includes a shield ground.

The cold junction compensation wiring base of this 8-terminal screw-clamp terminal base assembly can be installed on a DIN-rail both vertically and horizontally and provides both power and POINTBus communication pathway lines through the backplane. An orange mechanical key restricts any improper installation of an I/O module. Additionally, the entire 1734-TBCJC module can be assembled completely without needing any tools.

When thermocouples are being used, it is essential to maintain cold-junction compensation at the termination of the thermocouple wire. Cold-junction can be accomplished with the use of an external cold-junction compensator, but it’s far more appropriate and reliable to use the 1734-TBCJC cold junction compensation wiring base assembly instead.

This unit’s parts include interlocking side pieces, a mounting base, a DIN-rail locking screw, an RTB, an RTB handle, and a mechanical key. Replacement RTB parts correspond to the code 1734-RTBCJC.

The dimensions of the 1734-TBCJC are about 2.56 x 0.472 x 5.25 millimeters (65 x 12 x 133.4 inches), with its wire size being about 0.25 to 2.5 millimeters (22 to 14 AWG). The 1734-TBCJC weighs about 97.5 grams (3.44 ounces) with a supply voltage of 300 Volts at its maximum, a 10 A maximum terminal current, a field power bus supply voltage of 28.8 Volts DC and 120 to 240 Volts of AC Power, and a screw Torque of approximately 0.5 to 0.6 Nm.

Connection of the 1734-TBCJC terminal base assembly to the POINT I/O can be completed by positioning the assembly vertically above already connected modules and move the base downwards, allowing the interlocking side pieces to engage in the unit to the left. Press down on it strongly to seat the terminal base on the DIN rail, until and the base snaps into place. Check that the locking screw is positioned correctly in a horizontal position; the mechanical key (orange) should be rotated to the number that corresponds with the correct I/O module, in order to prevent the incorrect I/O module from being installed.

An RTB is distributed with the 1734-TBCJC assembly; to remove it, pull up the RTB handle part on top of it. This allows the mounting base to be removed and replaced without wiring removal.

The POINT I/O system has a built-in DIN-rail grounding. A zinc-plated chromate steel DIN-rail is recommended to establish correct grounding. Single terminal pin connections: 0 (N/A), 1 (N/A), 2 (N/A), 3 (Shield), 4 (1+), 5 (1-), 6 (0+), 7 (0-). More than 2 conductors should not be used on any single terminal pin.

1. What is the compatible thermocouple module for the 1734-TBCJC?

Compatible Thermocouple module is the 1734-IT2I.

2. What are compatible terminal base for use with the 1734-TBCJC?

Compatible terminal base are 1734-TB, 1734-TBS, 1734-TOP, or 1734-TOPS terminal bases.

3. What is the power input voltage rating of the 1734-TBCJC?

The 1734-TBCJC has input voltage rating of 28.8V DC, 120/240V AC.