AS-B814-108 Schneider Electric/Modicon 8-Point Relay Output Module

Description

Product Model: AS-B814-108

• Product Brand: Schneider Electric (Modicon)
• Product Series: Modicon “984” / 800-Series I/O Modules
• Product Features:
  • 8-channel relay output module (selectable normally-open / normally-closed) with up to 5 A at 30 V DC or 4 A at 230 V AC per channel.
  • Discrete output board intended for older Modicon PLC racks; user-configurable output type.
  • Compatible with modular I/O racks in industrial environments (material handling, packaging, legacy systems) under Schneider/Modicon.

Applications & Industry Context

In many industrial automation systems, legacy PLC architectures continue to serve as the backbone of control—handling input/output logic, machine sequencing, safety interlocks and discrete output functions. For such systems, the AS-B814-108 plays a key role: acting as a reliable output module, converting discrete logic signals from the PLC to real-world devices (relays, contactors, indicator lamps, solenoids).

Think of a packaging line: when a pneumatic actuator needs to be energized, or a conveyor motor starter needs to be triggered, a discrete output channel from the PLC must drive a real-world device. The AS-B814-108, with its 8 relay channels, is designed exactly for that — each channel is isolated, user-configurable (NO/NC), and rated to handle reasonable loads for industrial control.

In retrofit scenarios, many older machines still use the Modicon 800-Series rack architecture. Rather than replacing the entire control platform, maintenance teams can replace or expand discrete output modules — and the AS-B814-108 remains a stocked part in surplus markets. Because the module is well-tested and trusted, it provides a cost-effective path to maintain uptime. Vendors note the module is “new and refurbished available” and many offer 2-year warranties.

From a system integrator’s perspective: when you have 8 channels of discrete outputs required, each requiring up to 5 A at low DC voltage or 4 A at high AC voltage, the AS-B814-108 gives you the capability in one slot — maintaining simplicity, wiring clarity and modularity. In harsh environments (material handling, textile machines, packaging) where reliability matters, relay-based modules like this provide robustness, clear diagnostics and easy replaceability.

Product Role & System Fit

The AS-B814-108 is not a processor, not a communication gateway, and not a high-speed analog I/O board—it is a discrete output module designed for the Modicon 800-Series or 984-Series I/O racks. It interfaces via the I/O backplane in the PLC rack and communicates status and control to the CPU as part of the distributed I/O system.

When the CPU logic sets an output bit, the AS-B814-108 energizes the corresponding relay coil (or de-energizes depending on NO/NC setting), which then switches the external device. Because each channel is electrically isolated from the I/O bus and from other channels (via relay coils) the module provides load isolation, reduces noise coupling and simplifies wiring compared to transistor outputs in noisy environments.

Because this is a legacy module, its best fit is in existing installations using the Modicon 800/984 I/O family. In new designs, modern I/O platforms may be preferred, but when maintaining legacy machines, the AS-B814-108 remains relevant. It aligns with older wiring practices (screw-terminal outputs to relays/contactors), and many spare parts providers stock it. When specifying the module, engineers should verify load requirements (max current, voltage), output type (NO/NC), and rack compatibility (backplane slot, bus architecture).

Technical Features & Benefits

Here are some of the key features of the AS-B814-108 and how they translate into benefits on the plant floor:

• 8 Independent Relay Outputs
  The module provides 8 discrete channels — each one separately configurable for normally-open or normally-closed operation. This flexibility allows the module to serve various functions (e.g., motor starters, solenoids, indicator lamps) without external logic modifications.
• High Load Ratings for Discrete Devices
  Each channel is rated at up to 5 A for 30 V DC loads, or 4 A for 230 V AC loads. These ratings cover many common actuators and contactor coils in industrial systems, making the module broadly applicable.
• Configurable Output Type (NO/NC)
  The user can select normally-open or normally-closed operation per channel via onboard jumpers. This enables flexibility when integrating with existing wiring and devices without rewiring or external inversion logic.
• Electrical Isolation & Noise Immunity
  Each relay output is electrically isolated from the I/O bus and from other outputs — reducing risk of noise or load fault affecting other outputs or the bus. This is especially important in heavy-duty environments with motors, inductive loads or switching transients.
• Legacy Rack Integration & Maintenance Ease
  For systems built around the Modicon 800 or 984 series I/O rack, the AS-B814-108 is plug-and-play compatible—making module replacement, spares stocking and maintenance straightforward without redesigning wiring or control logic.
• Surplus Availability & Lifecycle Support
  Although a legacy module, many vendors offer refurbished or used stock with warranty (2-year from some suppliers) which keeps machines in service and avoids full system replacement.

Because of these features, the AS-B814-108 helps engineers maintain discrete output capacity, manage spare parts strategy, and keep older machines running reliably in production environments.

Technical Specifications Table

Note: Always consult the original product manual (if available) for voltage, current derating, environmental specs, and wiring guidelines before integration.

Installation & Maintenance Insights

From field experience and vendor documentation, here are practical tips when installing or maintaining the AS-B814-108:

• Backplane Slot & Bus Integration
  Ensure your rack is powered down before inserting or removing the module. Check that the module is properly seated in the I/O rack backplane and the bus connectors are clean and undamaged.
• Correct Output Wiring
  For each channel, ensure terminal wiring matches the configured mode (NO or NC). The module is shipped with all channels jumper-configured as Normally-Open by default. To change to Normally-Closed, you must move a jumper for each channel
• Load Compatibility Check
  Verify that the device you are driving (relay coil, solenoid, lamp, contactor) does not exceed the module’s rated 5 A/30 V DC or 4 A/230 V AC. If inrush current is high (e.g., motor starter), you may need an intermediate contactor rather than direct drive from module.
• Relay Contact Life & Load Type
  Respect the relay contact life expectancy and note that inductive loads (coils, solenoids) typically require contact suppression (snubbers or flyback diodes) to maintain long life.
• Labeling & Documentation
  Clearly label which rack slot the module occupies, note the base address, document jumpers and channel configuration. When you have multiple similar modules, this helps reduce mistakes during maintenance or replacement.
• Spare Module Strategy
  Since this is a legacy module, consider procuring a spare AS-B814-108 pre-tested unit to minimize downtime. Many vendors offer refurbished units with 2-year warranty.
• Regular Inspection
  Periodically inspect wiring terminals, look for signs of excessive heat, corrosion or vibration-damage. Relay modules can fail due to high vibration or improper load switching. Confirm that the module remains firmly seated and bus connectors are secure.
• Replacement & Downtime Planning
  When a channel fails, you can often replace the entire module (rather than individual relays) which restores all 8 channels. Maintain proper backup of your wiring documentation, and if possible test the new module off-line before returning to production.

By following these practices, the AS-B814-108 can reliably serve as your discrete output module in a legacy PLC environment with minimal surprises.