BQD390 - 90Amp Circuit Breaker

BQD390 - 90Amp Circuit Breaker

The Siemens BQD390 is a 90 Amp, 3-pole molded case circuit breaker designed for use in 480/277VAC three-phase panelboard systems. It's commonly installed in commercial and industrial facilities where branch circuits need protection from overloads and short circuits.

Using a thermal magnetic trip unit, the BQD390 provides two layers of protection. The thermal element responds to sustained overcurrent conditions, while the magnetic element reacts quickly when a short circuit or fault occurs. This type of protection is widely used throughout power distribution systems because it offers dependable performance without unnecessary complexity.

Whether you're installing it in a warehouse, office building, school, healthcare facility, or manufacturing plant, the Siemens BQD390 provides the ratings and protection characteristics commonly required for 480/277VAC electrical distribution systems.

Key Features and Benefits

• 90 Amp continuous current rating
• 3-pole configuration for three-phase electrical systems
• Rated for 480/277VAC applications
• Thermal magnetic trip unit for overload and short-circuit protection
• 14 kAIC interrupting capacity
• Siemens BQD series design
• Panelboard-mount construction
• Low-tab connection style
• Molded case circuit breaker design
• 100A frame size
• Suitable for 50/60 Hz electrical systems
• Commonly used in commercial, industrial, and construction applications
• Commonly used for lighting, HVAC, motor, pump, and power distribution circuits

Technical Specifications

• Manufacturer: Siemens
  
• Catalog Number: BQD390
  
• Series: BQD
  
• Current Rating: 90 Amps
  
• Number of Poles: 3
  
• Voltage Rating: 480/277VAC
  
• Interrupting Capacity: 14 kAIC
  
• Frequency Rating: 50/60 Hz
  
• Trip Unit Type: Thermal Magnetic
  
• Frame Size: 100A
  
• Mounting Type: Panelboard Mount
  
• Connection Type: Low Tab
  
• Circuit Breaker Type: Molded Case Circuit Breaker
  
• Enclosure Material: Molded Case
  
• Dimensions:
  • 5 in. D × 3 in. W × 3 in. H
• Maximum Ambient Operating Temperature: 40°C
  
• Net Weight: 1.649 lb
  
• Country of Origin: Mexico
  

Material Compliance and Certifications

• UL 489 Listed
• CSA C22.2 Certified
• RoHS Compliant (since July 1, 2006)
• REACH Information Available
• WEEE Take-Back Obligations Applicable

Where It Works Best

• The Siemens BQD390 is well suited for commercial and industrial facilities operating on 480/277VAC three-phase power systems. Typical installations include office buildings, schools, healthcare facilities, warehouses, manufacturing plants, retail centers, and other properties that depend on reliable electrical distribution. This breaker is commonly used to protect lighting systems, HVAC equipment, motors, pumps, compressors, and general branch circuits where a 90 Amp 3-pole circuit breaker is required.
• The BQD390 is frequently used during breaker replacements, panel upgrades, facility maintenance projects, and new electrical construction where a 90 Amp, 3-pole breaker is specified.