A1B390 - 90 Amp Circuit Breaker

A1B390 - 90 Amp Circuit Breaker

The A1B390 is a 3-pole, 90-amp thermal magnetic circuit breaker built for use in 240VAC distribution systems. Designed on the A1B frame, this bolt-on breaker is intended for proper form, fit, and functional replacement in compatible panelboards and switchgear. With a 10kA interrupting rating at 240VAC, it provides dependable protection against overloads and short circuits in commercial and light industrial applications. Its thermal magnetic trip unit responds to sustained overcurrents with a time-delay action while also reacting instantly to short-circuit faults. The bolt-on design ensures a secure, stable connection to the panel bus, helping maintain system integrity. For facilities maintaining existing A1B frame equipment, the A1B390 offers a straightforward solution that matches required ratings and physical configuration. These breakers are built to last and designed for consistent operation in everyday electrical environments.

Key Features and Benefits

• 90 Amp Rating: Suitable for branch circuits and feeders requiring 90A protection
• 3-Pole Design: Protects all three phases in 240VAC systems
• 10kA @ 240VAC Interrupting Capacity: Rated to safely clear fault currents up to 10,000 amps
• Thermal Magnetic Trip Mechanism: Provides both overload and short-circuit protection
• Bolt-On Mounting: Secures directly to compatible panelboards for proper electrical contact
• A1B Frame Compatibility: Designed for correct fit in equipment built for A1B frame breakers
• Durable Construction: Made for long-term service in commercial and industrial settings

Technical Specifications

• Part Number: A1B390
  
• Amperage: 90A
  
• Poles: 3
  
• Voltage Rating: 240VAC
  
• Interrupting Capacity: 10kA @ 240VAC
  
• Trip Type: Thermal Magnetic
  
• Mounting Type: Bolt-On
  
• Frame Type: A1B
  
• Approximate Height: 6 inches
  
• Approximate Weight: 2.25 lbs
  

Material Compliance and Certifications

• Industry Standards: The A1B390 molded case circuit breaker is manufactured to meet applicable industry standards for safety and performance. It is designed for installation in properly rated electrical equipment in accordance with the National Electrical Code (NEC) and local regulations. Always confirm system voltage, amperage, interrupting capacity, and panel compatibility before installation.

Where It Works Best

• This breaker is commonly used in:
• Commercial panelboards with 240VAC three-phase power
• Light industrial distribution systems
• Equipment requiring 90A, 3-pole protection
• Maintenance and replacement projects involving A1B frame breakers