3VA5330-5EC31-0AA0 - 300A Class MJAS 3-Pole Circuit Breaker

3VA5330-5EC31-0AA0 - 300A Class MJAS 3-Pole Circuit Breaker

The Siemens 3VA5330-5EC31-0AA0 is a solid, no-nonsense 300A circuit breaker built for people who just need things to work the way they should. It’s part of the 3VA5 series, which is widely used in commercial and industrial setups, so it’s not some niche or hard-to-match component. This one uses a thermal magnetic trip unit, meaning it handles both overloads and short circuits without requiring anything complicated to set up. The overload protection is fixed at 300 amps—so there’s nothing to dial in—and the instantaneous trip can be adjusted between 5 to 10 times the rated current. That gives you some flexibility where it actually matters. With a 35 kA rating at 480V, it’s built to deal with higher fault levels without hesitation. It’s the kind of breaker you’d drop into a panel and not think about again—which, honestly, is exactly what most people want.

Key Features and Benefits

• 300A rating for steady, everyday load protection
• 3-pole design for standard three-phase systems
• Thermal magnetic trip unit—simple and reliable
• Fixed overload protection (no guesswork)
• Adjustable instantaneous trip (5–10x) for short-circuit tuning
• 35 kA interrupting capacity at 480V AC
• 400A frame (3VA5 series)
• Built for consistent performance in demanding setups

Technical Specifications

• Manufacturer: Siemens
  
• Part Number: 3VA5330-5EC31-0AA0
  
• Series: 3VA5
  
• Poles: 3
  
• Amperage: 300A
  
• Frame Size: 400A
  
• Trip Unit: Thermal Magnetic (TM230)
  
• Overload Protection: Fixed at 300A
  
• Short-Circuit Protection: Adjustable (5–10x In)
  
• Interrupting Rating: 35 kA @ 480V AC
  
• Dimensions:
  • Height: 9.8 in
  • Width: 6.3 in
  • Depth: 5.9 in
• Lugs: Not included
  

Material Compliance and Certifications

• This breaker is UL listed, so it meets the standard requirements for use in U.S. electrical systems. It’s built to handle typical commercial and industrial conditions without cutting corners on safety or consistency.

Where It Works Best

• You’ll usually see this used in: Commercial buildings Industrial panels and machinery Main or sub-distribution panels Replacement jobs where specs need to match closely If you’re looking for something straightforward that does its job without extra complexity, this is exactly that.