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Square D QO2DTI mechanical interlock attachment for QO and QOB circuit breakers

SQUARE D

SQUARE D QO2DTI Interlock Attachment for QO/QOB circuit breakers

SKU CH-SQDA-YN5KK

Mechanical interlock attachment prevents simultaneous operation of two adjacent QO or QOB circuit breakers

  • Mechanical interlock prevents simultaneous operation of two breakers
  • Compatible with QO and QOB 1P and 2P miniature circuit breakers
  • Side-by-side mounting ensures only one breaker can be ON at a time
  • VisiTrip indication shows when a breaker has tripped
  • Trip-free toggle mechanism with quick make, quick break action

Mechanical Interlock for QO/QOB Breakers

This mechanical interlock attachment fits Square D QO and QOB miniature circuit breakers. It is designed for electrical installations that require two adjacent breakers to operate mutually exclusively. The kit suits residential, commercial and light-industrial panels where a single source must be selected at a time.

Prevents Simultaneous Activation

The attachment physically links the handles of two 2-pole breakers or one 2-pole and one 1-pole breaker mounted side by side. This mechanical constraint ensures only one breaker can be switched ON, eliminating the risk of parallel feed from two sources. It cannot be used with QOU series breakers.

Two-Breaker Limit and Compatibility

The device manages exactly two breakers in a side-by-side arrangement. It does not support three or more interlocked poles, nor does it fit QOU models. Installations needing a larger interlock group or a different breaker family will require a separate solution.

Highlights

  • Mechanical interlock prevents simultaneous operation of two breakers
  • Compatible with QO and QOB 1P and 2P miniature circuit breakers
  • Side-by-side mounting ensures only one breaker can be ON at a time
  • VisiTrip indication shows when a breaker has tripped
  • Trip-free toggle mechanism with quick make, quick break action

Specifications

BrandSQUARE D

Questions about this item

Will the interlock mechanism itself need periodic lubrication or replacement parts?

The mechanical interlock attachment is a passive hardware kit with no moving parts that wear out, so it does not require lubrication or scheduled replacement.

What stops me from forcing both breakers on if the interlock gets stuck?

The kit physically blocks the toggles so only one breaker can be switched ON at a time; it cannot be bypassed without removing the attachment.

Does the interlock add any heat or power draw when the breakers run continuously?

The attachment is purely mechanical and draws no power, so it adds no heat or electrical load during all-day operation.

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