990NAD23000

Configured for physical bus segment termination and node coupling in Modbus Plus network structures, the Schneider Electric 990NAD23000 (990NAD23000 Junction Box) provides direct physical/electrical execution. The component functions as an IP20 passive drop connection hardware assembly designed to link Programmable Logic Controller (PLC) nodes across legacy and active control architectures. It incorporates integral line termination circuitry to maintain impedance matching across differential transmission media without requiring active external signal conditioning units.

Suffix Breakdown & Model Matrix

Base Part Number	Termination Type	Ingress Protection Rating	Supported Automation Platforms
990NAD23000	Line Terminal Integrated	IP20	Modicon Quantum, Premium, TSX Micro, Momentum

Hardware Specifications

Parameter	Specification
Model	990NAD23000
Brand	Schneider Electric
Origin	France
Weight	0.23 kg
Dimensions	114 mm x 55 mm x 26 mm
Operating Temp	0 to 60 deg C
Power Consumption	Passive (0 W)
Accessory Category	Connection Accessories
Device Type	Junction Box with Line Terminal
Network Protocol	Modbus Plus
IP Protection Rating	IP20
Wiring Tool Requirement	Part Number 043509383
Package Quantity	Set of 1

Backplane Communication and Deterministic Network Interfaces

The module interfaces with Modicon Quantum, Premium, TSX Micro, and Momentum automation platforms, managing signal routing across RS-485 based Modbus Plus token-passing networks. The internal line terminal suppresses high-frequency reflections across the bus interface, preventing signal distortion at baud rates characteristic of deterministic Modbus Plus physical layers. Proper connection integrity minimizes packet drop rates and bus re-transmission latencies caused by trace mismatch or improper shield grounding paths across multi-node drop topologies.

Frequently Asked Questions

Q: Does the 990NAD23000 junction box require external DC control power to operate?

A: No. The unit functions as a passive physical layer interconnection device containing internal passive line termination components, requiring no auxiliary power supplies.

Q: What specific wiring tool is specified for conductor installation on this assembly?

A: Wire termination requires the standard Schneider Electric tool part number 043509383 to secure field conductors to the internal terminal blocks without damaging internal contacts.

Q: Can this junction box be installed in outdoor unsealed environments without an enclosure?

A: No. The unit carries an IP20 protection rating, requiring installation inside a protective enclosure or panel that shields against ambient moisture, conductive dust, and free water.

Field Installation Guidelines

1. Ensure the control cabinet is powered down before routing shielded twisted-pair Modbus Plus cables into the junction box.
2. Strip network cable jackets using tool 043509383, ensuring signal conductors and drain wires are exposed to correct specifications without nicking the copper strands.
3. Connect signal lines to designated terminal pins, ensuring the internal line termination resistor remains configured for end-of-line bus nodes.
4. Secure the shield wire directly to the internal grounding terminal to ensure low-impedance high-frequency noise dissipation to the main DIN-rail ground ground plane.
5. Mount the assembly securely inside an enclosure meeting minimum IP54 standards if ambient dust or corrosive airborne agents are present.

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