The **QO2201201** is a specific type of circuit breaker manufactured by Square D (Schneider Electric). It is part of the **QO (Quick-Open)** product line, which is widely considered the industry standard for residential and commercial electrical protection. --- ## 1. Technical Specifications The model number "QO2201201" defines its physical and electrical characteristics. | Parameter | Specification | | :--- | :--- | | **Manufacturer** | Square D (Schneider Electric) | | **Product Type** | Miniature Circuit Breaker (MCB) | | **Poles** | 2-Pole (Common Trip) | | **Amperage Rating** | 20 Amps | | **Voltage Rating** | 120/240V AC | | **Interrupting Rating** | 10 kA (Kilo-Amps) | | **Mounting Type** | Plug-on | | **Wire Size** | #14–8 AWG (Aluminium/Copper) | --- ## 2. Key Electronic & Mechanical Components The QO2201201 utilizes a sophisticated internal mechanism to ensure circuit safety: ### A. Visi-Trip™ Indicator One of the most recognizable electronic/mechanical features is the **red indicator window**. When the breaker trips, a mechanical flag moves into a small window. This allows a user to instantly identify which breaker has failed without having to feel the handle position. ### B. Thermal-Magnetic Trip Mechanism This breaker uses a dual-protection system: 1. **Thermal Protection:** A bimetallic strip reacts to prolonged overloads (heating up and bending) to trip the breaker. 2. **Magnetic Protection:** An internal solenoid reacts to instantaneous high-current surges (short circuits), pulling the trip bar immediately. ### C. QO "Quick-Open" Design The "QO" designation refers to the high-speed opening of the contacts. By forcing the contacts apart faster than standard breakers, it reduces the duration of an electrical arc, significantly lowering the risk of fire and reducing wear on the device's internal silver-alloy contacts. --- ## 3. Application and Compatibility ### Common Uses: * **240V Appliances:** Specifically designed for heavy-duty items like well pumps, water heaters, small air conditioning units, and electric heaters. * **Safety:** Because it is a 2-pole breaker, if one leg of the circuit fails, the internal "common trip" mechanism ensures both legs are disconnected simultaneously. ### Panel Compatibility: This breaker is exclusively designed for **Square D QO Load Centers**. It is **not** compatible with: * Square D Homeline (HOM) panels. * General Electric (GE), Siemens, or Eaton panels. --- ## 4. Safety and Ratings * **UL Listed:** Tested to meet Underwriters Laboratories safety standards. * **HACR Rated:** Certified for use with Heating, Air Conditioning, and Refrigeration equipment.