Description
Product Overview
The ABB Bailey NTR002-A is a legacy terminal/interface component associated with the Bailey INFI 90 and Net 90 control-system families. Its primary role is to provide the field-side termination and electrical interface between Bailey I/O/control hardware and external plant wiring. It is therefore better understood as a terminal unit than as a standalone PLC or DCS processor. Bailey system parts listings identify NTR002-A as a terminal unit and indicate that it replaced the earlier NTR002 designation.
The ABB NTR002-A appears in current industrial spare-parts inventories as a digital I/O termination device, with commonly published specifications of 16 channels and 24 VDC. However, some secondary sources incorrectly assign unrelated functions to the same part number, including temperature interfaces and general-purpose controller boards. Those descriptions should not be used as engineering references.
For maintenance of an existing ABB Bailey NTR002-A installation, the critical identification points are the complete part number, terminal arrangement, connected I/O module, cable type, field-voltage level, and actual signal direction. A replacement should be electrically and mechanically matched to the existing Bailey I/O architecture rather than selected solely from a generic “terminal unit” description.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | ABB Bailey |
| Model | NTR002-A |
| Product Type | Digital I/O Terminal Unit |
| System Family | Bailey INFI 90 / Net 90 |
| Typical Function | Digital I/O field termination |
| Common Channel Count | 16 channels |
| Common Signal Rating | 24 VDC |
| Signal Type | Digital |
| Signal Direction | Verify against associated I/O module |
| System Interface | Bailey I/O architecture |
| Mounting | Cabinet/rack termination assembly |
| Replacement | Replaces NTR002 in documented applications |
| Firmware | Not normally applicable to passive termination hardware |
| Field Wiring | Application dependent |
| Operating Temperature | Verify against original ABB documentation |
| Protection Rating | Verify exact assembly |
The 16-channel/24 VDC identification is supported by secondary industrial-parts references, while the replacement relationship to NTR002 appears in Bailey parts documentation.
Main Features and Advantages
Bailey INFI 90 / Net 90 Compatibility
The NTR002-A belongs to the older Bailey control-system hardware ecosystem. It is intended to provide the physical termination point required by compatible I/O/control equipment rather than functioning as an independent controller.
Digital Field Signal Interface
The commonly documented configuration is a 16-channel, 24 VDC digital interface. This makes the unit suitable for field status and discrete-control wiring in legacy Bailey systems.
Replacement for Earlier NTR002
One Bailey-related parts reference specifically lists as the terminal unit replNTR002. This is useful when maintaining an older Net 90 or INFI 90 installation where the original is no longer readily available.
Cabinet-Level Maintainability
A dedicated termination unit keeps field wiring separate from the controller electronics. For maintenance personnel, this makes it easier to isolate field wiring, inspect terminals, and replace associated control-system electronics without unnecessarily disturbing the entire cabinet wiring arrangement.
Legacy System Support
For an operating Bailey installation, maintaining a tested spare terminal unit can be worthwhile because a terminal fault may appear initially as an I/O-module or controller communication problem.
NTR002-A
Application Scenarios
- ABB Bailey INFI 90
- Bailey Net 90
- Digital field-status collection
- Discrete control signals
- Relay/status interfaces
- Valve and actuator status
- Motor running/tripped indications
- Limit-switch monitoring
- Legacy DCS cabinet maintenance
- Bailey I/O replacement projects
Engineer’s Guide: Field Pitfalls
WARNING 1 — Do not e with NTR003-A
These are different Bailey part numbers. A search result may show them together because both appear in legacy Bailey inventories. The exact model on the installed hardware must be matched.
WARNING 2 — Verify input vs. output direction
This is especially important because online descriptions conflict. One source ides as a digital-output termination module, while another describes it as a 16-channel digital-input terminal unit.
Do not determine signal direction fe model number alone.
Check:
- Associated I/O module
- Terminal labels
- Cabinet drawings
- Field wiring
- Cable pinout
- Existing configuration
WARNING 3 — Do not use c specifications
At least one online listing incorrectly ides as a residual-current circuit breaker, while another calls it a temperature-interface module. These are clear examples of model-number contamination in secondary databases.
WARNING 4 — Verify the cable and terminal arrangement
Even if the replacement has the same model number, connector condition and terminal configuration should be checked before installation. Legacy Bailey systems frequently depend on specific termination assemblies and cable arrangements.
WARNING 5 — Check the associated I/O module
e should be evaluated as part of the complete I/O path:
Field d→ termination → Bailey I/O module → controller/network
A fault at any point can produce similar symptoms at the operator station.
Frequently Asked Questions
WhatB ?
The is a legacy terminal/interface unit used with Bailey INFI 90 and Net 90 systems. Bailey-related parts documentation identifies it as a replacement for .
s an I/O module?
It is more accurately classified as an I/O terminal/interface unit rather than the main electronic I/O processing module.
How many channels does it have?
Secondary industrial-parts references commonly idente as a 16-channel, 24 VDC digital termination unit.
Is it an input or output terminal?
This requires verification from the installed system. Public listings conflict on this point, so I would not specify input/output direction without the associated I/O module or cabinet documentation.
s repla002?
Yes. A Bailey-related parts listing explicitly identifies as the terminal unit replNTR002.
What should be checked before purchasing?
For a replacement , verify:
- Exact part number.
- Terminal/connector layout.
- Channel count.
- 24 VDC field-signal compatibility.
- Input/output direction.
- Associated Bailey I/O module.
- Cable type and pinout.
- Cabinet mounting arrangement.
- Terminal condition.
- Continuity of every channel.
- Field wiring insulation.
- Actual I/O operation after installation.
Bottom line: ABBy is best treated as a legacy INFI 90/Net 90 digital I/O terminal/interface unit. The commonly published configuration is 16-channel, 24 VDC, and Bailey-related documentation identifies it as a replacement for . Because online databases contain conflicting descriptions, the associated I/O module and cabinet wiring should be used to confirm whether the particular installation is an input or output application before procurement.
