THQB2120ST1 - 20Amp Circuit Breaker

THQB2120ST1 - 20 Amp Circuit Breaker

The THQB2120ST1 is a 20-amp, 2-pole molded case circuit breaker designed to provide dependable circuit protection in your commercial, industrial, and institutional electrical distribution systems. As part of the trusted THQB Q-Line series, this bolt-on breaker combines reliable overcurrent protection with the added functionality of a 120VAC shunt trip, allowing remote tripping capabilities for enhanced safety and control. Its compact footprint makes it well-suited for panelboard applications where space efficiency and consistent performance are important. Featuring a 10kA interrupting rating at 120/240VAC, the THQB2120ST1 helps safeguard electrical equipment and branch circuits against overloads and short circuits while meeting modern electrical safety requirements. HACR-rated construction further expands its suitability for heating, air conditioning, and refrigeration applications.

Key Features and Benefits

• 20 Amp Continuous Protection: For branch circuits requiring reliable overcurrent protection.
• 2-Pole Configuration: Designed for 120/240VAC electrical systems.
• Integrated 120VAC Shunt Trip: Enables remote breaker tripping for emergency shutdown systems, safety interlocks, and building automation applications.
• Bolt-On Mounting Design: Helps provide a secure installation within compatible panelboards.
• 10kA Interrupting Capacity: At 120/240VAC supports protection against fault conditions.
• Q-Line Series Compatibility: For use in designated Q-Line electrical distribution equipment.
• HACR Rated: For heating, air conditioning, and refrigeration applications.
• Molded Case Construction: Is engineered for durability and long service life in demanding environments.

Technical Specifications

• Part Number: THQB2120ST1
  
• Type: THQB
  
• Circuit Breaker Style: Molded Case Circuit Breaker
  
• Series: Q-Line
  
• Mounting Type: Bolt-On
  
• Poles: 2
  
• Amperage Rating: 20 Amps
  
• Voltage Rating: 120/240VAC
  
• Interrupting Rating: 10kA @ 120/240VAC
  
• Shunt Trip Voltage: 120VAC
  
• HACR Rated: Yes
  
• Dimensions:
  • Height: 3.5 in.
  • Width: 3.0 in.
  • Depth: 2.81 in.

Material Compliance and Certifications

• Application Compliance: The THQB2120ST1 is manufactured for use in electrical distribution systems that require dependable circuit protection and safe operation.
• HACR Rating: Its HACR rating supports applications involving heating, ventilation, air conditioning, and refrigeration equipment.
• Installation Requirements: Users should always verify local code requirements, panel compatibility, and installation specifications before use.

Where It Works Best

• The THQB2120ST1 is an excellent choice for commercial buildings, industrial facilities, schools, healthcare environments, office complexes, and other applications that require remote disconnect functionality. The built-in 120VAC shunt trip makes it particularly valuable for emergency power shutdown systems, fire alarm interfaces, access control systems, safety interlocks, and automated building controls. Its combination of dependable overcurrent protection and remote tripping capability helps facility managers and electrical professionals maintain safer, more responsive electrical systems.