Abb THAUX21D Auxiliary Switch Dpdt

Product Description

The ABB THAUX21D is a double-pole double-throw (DPDT) auxiliary switch designed for use with compatible ABB motor starters and contactors. Auxiliary switches provide electrical status feedback from the main contactor, allowing control circuits to monitor whether a starter is open or closed. The THAUX21D mounts directly to the contactor body and wires into the low-voltage control circuit. It is a standard accessory installed by licensed electricians and industrial maintenance technicians working on motor control centers and panel boards.

The THAUX21D is suited for commercial and industrial applications where status indication, interlocking, or control sequencing is required. Typical installations include motor control centers, machine control panels, and HVAC equipment starter assemblies. The DPDT configuration provides two sets of normally open and normally closed contacts, supporting multiple control circuit functions from a single auxiliary switch body.

Key Features

• DPDT contact configuration provides both normally open and normally closed outputs
• Direct-mount design attaches to the contactor body without separate hardware
• Supports status indication and interlocking in low-voltage control circuits
• Compact form factor suited for panel and motor control center installations

Compatibility

Designed as an OEM-style auxiliary switch accessory for compatible ABB contactors and motor starters. Consult ABB documentation to confirm fitment with your specific contactor series before ordering.

Installation Notes

Installation should be performed by a licensed electrician in accordance with NEC requirements. De-energize and lock out the contactor and all associated control circuits before attaching or removing the auxiliary switch. Verify contact ratings are appropriate for the control circuit voltage and current before wiring. Do not exceed the rated switching capacity of the auxiliary contacts.

Technical Specifications

• Contact Configuration: DPDT (Double-Pole Double-Throw)
• UPC: 78316416128

Standard Information

• Brand: ABB
• Manufacturer Part Number: THAUX21D