Overview
The Siemens BQ3B015 is a Type BQ molded case circuit breaker designed for reliable overload and short-circuit protection in three-phase electrical systems. These 3-pole 15-amp circuit breakers operate at 240VAC and deliver a 10 kiloampere (kA) interrupting rating, making them suitable for general-purpose industrial and commercial panel applications. This lot includes two units in used condition, offering cost-effective protection for replacement and retrofit projects.
Key Features
- Thermal-magnetic trip mechanism – Detects and clears overloads and faults automatically
- Bolt-on mounting – Integrates directly into compatible BQ-frame panelboards without rewiring
- Load-side lugs – Simplifies conductor connections and reduces installation time
- Common-trip design – All three poles trip simultaneously for coordinated protection
- UL listed – Meets safety and performance standards for North American installations
Technical Specifications
The BQ3B015 breaker operates across a wide voltage and current range, providing dependable protection:
- Voltage Rating: 240VAC at 50/60 Hz
- Current Rating: 15 amperes at 40°C
- Number of Poles: 3
- Trip Type: Thermal and Fixed Magnetic
- Interrupting Rating: 10,000 AIC (amperes interrupting capacity) at 240VAC
- Terminal Type: Load Lug (supplied with unit)
- Wire Size: 14–10 AWG (copper), 12–10 AWG (aluminum)
- Frame Type: BQ
- Mounting Style: Bolt-on panelboard
- Dimensions: 3″ W × 3″ D × 3.75″ H
- Approval: UL Listed
Typical Applications
The BQ3B015 is commonly deployed in:
- Industrial control panels and motor starter circuits
- Commercial service entrance and distribution equipment
- Three-phase lighting and HVAC branch circuits
- Equipment replacement and system upgrades
- Retrofit installations where BQ compatibility is required
Compatibility & Replacements
The Siemens BQ3B015 is a non-interchangeable trip breaker compatible only with BQ-frame panelboards. It cannot be substituted into newer Siemens BL or other frame types without panel modification. This breaker is now considered obsolete for new installations but remains essential for maintaining and upgrading legacy electrical systems. Verify your panelboard frame type and clearances before ordering. This lot of 2 units provides cost savings and reduces lead times for facilities requiring backup protection or simultaneous repairs.
