Product Details

Modicon AS-003B-104 is a sturdy modular relay and reliable control relay unit designed for legacy Modicon automation cabinets. This legacy relay part receives low-level control signals from PLC I/O modules and switches heavier load circuits for valves, motors, indicators and auxiliary contactors. It adopts compact modular construction for neat installation inside control panels and provides electrical isolation between the low-voltage control side and high-power load side, protecting PLC cards from surge and back EMF damage. As a discontinued spare, this modular relay is widely used for direct replacement of aged or burnt-out relay components, allowing old automation racks to maintain safe and reliable logic switching without full cabinet reconstruction.

Basic Parameters

Brand: Modicon

Model: AS-003B-104

Product Type: Modular Control Relay

Coil Voltage: 24 VDC

Contact Configuration: SPDT

Rated Contact Current: 5 A

Rated Contact Voltage: 250 VAC

Termination: Screw terminal connection

Mounting: DIN rail mounting

Product Status: Discontinued legacy spare

Net Weight: Approximately 0.09 kg

Supported Functions

This modular relay supports signal amplification and electrical isolation between PLC logic signals and field loads. The control relay unit executes on-off switching triggered by automation logic and provides auxiliary contact feedback for interlock and alarm circuits. This legacy relay part can be cascaded with other protection components and supports fast replacement during on-site maintenance to cut downtime.

Core Functions

As a key control relay unit, this modular relay converts weak PLC drive signals into reliable switching action for heavy field loads. Its isolated contacts separate control and power circuits to suppress electrical noise and back-surge. This legacy relay part serves as a drop-in replacement to restore safe load switching for ageing Modicon automation racks.

Hardware Specifications & Environmental Features

Operating Temperature: -10°C ~ +60°C

Storage Temperature: -20°C ~ +70°C

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

Housing: Flame-retardant plastic housing

Contact Material: Silver alloy for arc resistance

Anti-interference: Built-in coil suppression diode

Compatibility: Matches 800 series backplane and compatible peripheral modules

Industry Applications: Applied in legacy petrochemical distributed control, old paper making production automation, material handling conveyor lines, packaging and textile machinery, water treatment remote signal collection and large conveyor remote I/O control racks.

Note: Confirm 800 series backplane compatibility, pulse signal type, counting mode and preset logic before ordering.

This is from our current stock.

available stock.xlsx