3VA5340-7EC31-0AA0 - 400A Class CJAS 3-Pole Circuit Breaker

3VA5340-7EC31-0AA0 - 400A Class CJAS 3-Pole Circuit Breaker

The Siemens 3VA5340-7EC31-0AA0 is one of those breakers you spec when you don’t want surprises later. It’s a 400A, 3-pole unit from the 3VA5 line, built for solid, everyday protection in commercial and industrial setups. This one uses a thermal magnetic trip, so it covers both overloads and short circuits without getting complicated. The overload is fixed at 400 amps—no adjustments, no guesswork. On the short-circuit side, it trips in the 5 to 10 times range, which is pretty standard for this class and works well in most real-world applications. Where it really earns its place is fault handling. With a 100 kA rating at 480V, it’s suited for systems where available fault current is on the higher side. In other words, it’s built for environments where you actually need that level of protection—not just checking a box. Physically, it’s compact enough for a 400A frame, so it won’t fight you during install. Just note—lugs aren’t included, which is typical, but something to plan for.

Key Features and Benefits

• 400 amp rating for higher-load distribution
• 3-pole design for standard three-phase systems
• Thermal magnetic trip—simple and proven protection
• 100 kA interrupting rating at 480V AC
• Fixed 400A overload (no field adjustment needed)
• Instantaneous trip range of 5–10x for short-circuit response
• Compact 3VA5 frame—easier to work into panels
• Straightforward setup, no unnecessary complexity

Technical Specifications

• Part Number: 3VA5340-7EC31-0AA0
  
• Series: 3VA5
  
• Amperage: 400A
  
• Poles: 3
  
• Trip Type: Thermal Magnetic (TM230)
  
• Overload Protection (Ir): 400A (fixed)
  
• Short-Circuit Protection (Ii): 5–10x
  
• Interrupting Rating: 100 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 built to meet UL requirements for molded case circuit breakers, so it fits into projects where compliance isn’t optional. Materials and construction are in line with what you’d expect from Siemens—designed for consistent performance under load.

Where It Works Best

• You’ll typically see this model used in:
• Commercial panelboards and switchgear
• Manufacturing and industrial equipment protection
• Facilities with a higher available fault current
• Large HVAC or mechanical systems
• Retrofit jobs where a reliable 400A breaker is needed