Allen-Bradley 100-DS1-20 2NO Side-Mount Auxiliary Contact Block For 100-D IEC and NEMA 300 Motor Starters, Left or Right Inside Mounting

The Allen-Bradley 100-DS1-20 is a side-mounted auxiliary contact block engineered to extend the control and signaling capability of compatible Allen-Bradley contactors and motor starters. As a factory-style accessory for Bulletin 100-D/104-D IEC contactors and NEMA 300 family starters, it delivers a clean, integrated way to add more auxiliary contacts without redesigning the panel layout.

Why It Helps
By providing dedicated auxiliary contacts for logic and status circuits, the 100-DS1-20 keeps high-voltage power wiring and low-level control signals clearly separated. Panel builders and maintenance teams gain extra points for interlocks, indication lights, or PLC inputs without changing the main contactor size. Side mounting allows flexible placement on the left or right of the host device, making it easier to route wiring in tight control enclosures while maintaining an Allen-Bradley OEM accessory solution.

Key Highlights

• Purpose-built auxiliary contact expansion
  Designed specifically to add auxiliary contacts to compatible Allen-Bradley 100-D/104-D and NEMA 300-series contactors and starters, supporting clean integration into existing Rockwell-based control systems.

• Side-mounted, left or right installation
  Installs on either side of the contactor or starter with standard fixing screws, giving panel designers flexibility to optimize wire routing, spacing, and accessibility in crowded control cabinets.

• Dedicated auxiliary contacts for logic and status
  Provides normally open auxiliary contacts dedicated to signaling and control tasks, allowing main power contacts to remain focused on motor or load switching while control circuits receive clear, isolated feedback.

• Compatible with IEC and NEMA platforms
  Supports both IEC 100-D/104-D contactors and NEMA size 4–5 300, 305, and 309 motor starters, giving OEMs and MRO teams a single accessory that fits across multiple Allen-Bradley motor control platforms.

• Compact, lightweight accessory
  The compact housing and light weight help preserve existing panel layouts and minimize mechanical stress on the host contactor, while still delivering robust auxiliary contact performance.

System Compatibility
The 100-DS1-20 is intended for use alongside Allen-Bradley 100-D/104-D IEC contactors and NEMA size 4–5 Bulletin 300, 305, and 309 contactors or motor starters. In these systems, it supports control circuits such as interlocks, status indication, and PLC input signaling that must follow the operation of the main contactor without carrying the motor load current itself.

Applications
Typical applications include motor control centers, industrial automation panels, and process equipment where additional auxiliary contacts are required for feedback or permissive circuits. The 100-DS1-20 is suited to OEM machine builders, system integrators, and maintenance teams standardizing on Allen-Bradley contactors and motor starters. In these environments it provides a practical, OEM-aligned way to expand auxiliary signaling while maintaining the reliability and consistency expected from Rockwell Automation components.