Allen-Bradley 1745-E101 Expansion Chassis

The Allen-Bradley 1745-E101, also cataloged as the 1745-E101 PLC Expansion Unit, operates as a dedicated hardware component for localized digital I/O processing within Allen-Bradley SLC 100 platforms.

Hardware Specifications

Allen-Bradley Technical Characteristics

• Backplane Bus Communication Velocity: Transfers high-speed input/output bit states directly to the main processor backplane interface without introducing software cycle execution delays.
• I/O Density Scaling: Adds 10 discrete 115 VAC inputs and 6 electromechanical relay outputs to expand field device density within a single rack assembly.

Frequently Asked Questions

Q: Can the 1745-E101 expansion unit be connected to the main processor while supply voltage is active?

A: No. Hot-swapping expansion units or interconnect cables under power can disrupt backplane logic timing and cause CPU bus fault trips.

Q: What is the operating input voltage range for the 115 VAC discrete input channels?

A: The 10 discrete AC inputs accept operational field signal levels between 85 VAC and 132 VAC at 50/60 Hz.

Q: Does the 1745-E101 supply power to connected external field loads on its relay outputs?

A: No. The relay contact outputs provide dry electromechanical contacts; field power must be supplied through an external circuit fused within the rated load limits.

Field Installation Guidelines

1. Disconnect all primary power sources supplying the SLC 100 main unit and expansion unit before making physical wiring connections or mounting.
2. Secure the expansion chassis to a grounded metal enclosure panel using standard mounting hardware to ensure proper mechanical and thermal stability.
3. Route field input wiring and AC power distribution conductors separately from low-voltage communication cables to prevent electromagnetic noise interference.
4. Maintain a minimum clearance of 2.0 in (50.8 mm) on all sides of the unit for passive thermal convective cooling.