3VA5340-5EF31-0AA0 - 400A Class MJAS 3-Pole Circuit Breaker

3VA5340-5EF31-0AA0 - 400A Class MJAS 3-Pole Circuit Breaker

When you’re dealing with 400-amp loads, you don’t want to guess if your breaker can handle it—you want something you know will. The Siemens 3VA5340-5EF31-0AA0 is built for that kind of job. It’s a 3-pole thermal magnetic circuit breaker from the 3VA5 line, designed to protect your system without interfering with normal operation. One thing people like about this model is the adjustability. The overload protection can be set anywhere from 320A up to 400A, so you’re not locked into a fixed setting. The instantaneous trip (short-circuit protection) is adjustable too, from 5 to 10 times the rated current. That gives you more control when coordinating protection across a system and avoiding unnecessary trips. It’s also rated at 35 kA at 480V AC, which puts it right where it needs to be for many commercial and industrial setups. Whether you’re replacing an existing unit or building out a new panel, this breaker is made to handle real-world conditions without being overly complicated.

Key Features and Benefits

• 400A capacity for higher-load applications
• Thermal magnetic trip unit (TM240) for combined protection
• Adjustable overload range: 320A to 400A
• Instantaneous trip adjustable from 5–10x
• 35 kA interrupting rating at 480V AC
• 3-pole configuration for three-phase systems
• Part of the Siemens 3VA5 series

Technical Specifications

• Part Number: 3VA5340-5EF31-0AA0
• Series: 3VA5
• Type: 3VA53
• Poles: 3
• Amperage: 400A
• Frame Size: 400A
• Interrupting Class: Class M (MJAS)
• Interrupting Rating: 35 kA @ 480V AC
• Trip Unit: TM240 (Thermal Magnetic)
• Overload Protection (Ir): 320A – 400A
• Short-Circuit Protection (Ii): 5–10x
• Dimensions: 9.8" H x 6.3" W x 5.9" D
• Lugs: Not included

Material Compliance and Certifications

This breaker is UL-listed and built to meet standard North American electrical requirements. It’s designed for safe operation in systems where consistent performance matters.

Where It Works Best

You’ll typically see this used in commercial buildings, industrial facilities, and larger electrical distribution systems. It’s a good fit for panelboards, switchgear, and motor control setups that require 400A protection and some level of adjustment.