Model Definition

490: Modicon network accessory series

NAC: Modbus Plus surge protection/lightning arrestor category

72100: MB+ lightning arrestor model code

Technical Specifications

Hardware & Interface

Protocol: Modbus Plus (MB+), 1 Mbps

Ports: Two MB+ communication ports (in/out)

Connection: Screw terminals for MB+ bus wiring

Surge Protection: Protects against common-mode/differential-mode surges

Isolation: Galvanic isolation between line segments

Enclosure: Industrial metal housing, DIN-rail mountable

Weight: ~0.7 kg

Dimensions: Standard industrial enclosure

Environmental & Performance

Operating Temp: 0 °C to +60 °C

Storage Temp: -25 °C to +80 °C

Relative Humidity: 5%–95%, non-condensing

Surge Rating: Designed for industrial lightning and surge events

Compliance: Meets industrial surge protection standards

Core Functions

Surge Suppression: Absorbs and diverts high-voltage transients from lightning or grid switching

Line Isolation: Isolates sensitive MB+ nodes from surge-induced damage

Network Protection: Shields repeaters, PLCs, and field devices on MB+ networks

Signal Integrity: Preserves 1 Mbps MB+ communication during normal operation

Application Scenarios

Outdoor or exposed MB+ network runs (e.g., between buildings)

Industrial sites prone to lightning strikes or power grid fluctuations

Long-distance MB+ communication lines in large factories

Legacy Modicon Quantum PLC systems requiring surge protection

Usage & Maintenance

Mount on standard DIN rail in control cabinets or enclosures

Connect MB+ incoming line to "IN" port and outgoing line to "OUT" port

Verify tight, secure wiring to avoid signal loss or arcing

Inspect periodically for damage or corrosion; replace if degraded

For new installations, migrate to modern Ethernet with surge protection