PLC Chassis | Schneider Electric ASH827103

The ASH827103 (also designated as AS-H827-103) is an 8-slot passive backplane rack chassis designed for Schneider Electric's Modicon 800 Series I/O platform. Engineered for standard 19-inch 2U rack mounting, this unit provides structural housing, noise-filtered power distribution, and high-speed data bus connectivity for up to eight digital and analog I/O modules in distributed control architectures.

Backplane Architecture and Signal Distribution

The passive backplane integrates a 16-bit parallel data bus for high-speed module-to-module communication, along with dedicated interrupt lines for time-critical automation processes. Each slot features a 48-pin DIN connector with gold-plated contacts to ensure low contact resistance and reliable connection under industrial vibration. Separate power planes for 5 VDC logic and 24 VDC field supply feature individual per-slot noise filtering to maintain signal integrity across all traces.

Power Management and Circuit Protection

The chassis accepts external power through a front-facing 25-pin D-sub connector and screw terminal blocks accommodating wire gauges from 0.5 mm² to 2.5 mm². The backplane distributes up to 8 A total on the 5 VDC bus and 4 A total on the 24 VDC bus, capped at 2 A maximum per slot. Resettable per-slot fuses safeguard against overcurrent conditions and short circuits, preventing localized faults from damaging adjacent control hardware.

Physical Integration and Mounting

Housed in an IP20 enclosure, the unit features a standard 19-inch width (482 mm) and a 2U rack height (89 mm) with a depth of 180 mm. Integrated mounting brackets allow rapid installation into standard control cabinets. Thermal management utilizes natural convection through side ventilation slots and metal frame copper trace heat dissipation, supporting full 8-slot operation across an ambient operating range of 0 °C to 60 °C.

Parameter Specification

Frequently Asked Questions

Q: What module types can be installed in the ASH827103 chassis slots? A: All eight slots are physically and electrically identical, allowing any combination of standard or high-speed Modicon 800 Series digital and analog I/O modules to be installed without slot restrictions.

Q: How is external 24 VDC supply connected to the rack? A: Power input is connected via the front-facing 25-pin D-sub connector or the integrated screw terminal blocks, which accept wiring from 0.5 mm² to 2.5 mm².

Q: Does the backplane require active cooling? A: Forced-air cooling is generally not required for standard operations up to 60 °C, as the frame is designed for natural convection airflow. However, external cabinet ventilation is recommended when fully populating the rack with high-power modules.