Product Overview: 1746-NT4/B Thermocouple Input Module
The Allen-Bradley 1746-NT4/B is a four-channel thermocouple and millivolt input module for the SLC 500 platform. It converts temperature and low-level voltage signals into 16-bit digital data. Because the module includes cold-junction compensation, it delivers engineering-grade accuracy for process monitoring. However, Rockwell Automation lists the Bulletin 1746 I/O family as discontinued. Therefore, verify current lifecycle status and availability with AutoDCSTech before ordering.
Key Specifications of the 1746-NT4/B
- Inputs: 4 thermocouple/mV channels plus CJC
- Thermocouple types: J, K, T, E, R, S, B, N
- Millivolt ranges: ±50 mV and ±100 mV
- Converter: 16-bit
- Backplane current: 60 mA at 5V DC; 40 mA at 24V DC
- Operating temperature: 0 to 60 C
- Isolation: Refer to official datasheet for isolation rating.
Installation and Setup
Mount the 1746-NT4/B in a 1746 chassis with 4, 7, 10, or 13 slots. The backplane supplies 5.1V DC at 10A and 24V DC at 2.88A to all modules. However, field-side load power requires an external supply. Use removable terminal blocks for field wiring. Bulletin 1492 pre-wired interface cables are available. Critically, this module is not hot-swappable. Do not install, remove, or wire it with power applied. Slot 0 remains reserved for the processor or a 1747-ASB adapter.
Compatibility and Integration
The 1746-NT4/B operates exclusively within SLC 500 systems. It communicates through the 1746 backplane. Therefore, it does not support standalone operation. For migration, Rockwell recommends Compact 5000 I/O or ControlLogix analog modules such as the 1756-IF8. If you integrate this module into a modern network, an external gateway or connection module may be required. Confirm all cables and gateways with AutoDCSTech before purchase.
Maintenance and Reliability
Inspect terminal connections periodically for corrosion or loosening. Because thermocouples generate low-level signals, keep wiring away from high-voltage conductors. The module operates from 0 to 60 C with 5-95% RH non-condensing. Consequently, install it in a controlled enclosure. This practice prevents condensation and thermal drift. For safety, follow the manufacturer's safety manual during all maintenance activities.
Product Support and Availability
The 1746-NT4/B is discontinued. Contact AutoDCSTech with your exact requirements for precise matching. Our team provides engineering-grade support for legacy SLC 500 modules.
Availability & Condition at AutoDCSTech
| Part Number | 1746-NT4/B |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
