Siemens B390H - 90 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Meet the Siemens B390H 90A 240V 3-Pole Bolt-On Molded Case Circuit Breaker — a purpose-built solution for dependable branch circuit protection in panelboards and load centers. This unit is engineered for demanding electrical environments, delivering consistent protection with a focus on reliability and ease of installation.

Key advantages at a glance:

• Secure bolt-on mounting: a rigid, vibration-resistant bus connection that stays locked in place, helping maintain electrical integrity even in demanding service conditions.
• Thermal-magnetic trip unit: combines thermal overload protection with magnetic short-circuit fast-tripping for stable, repeatable performance and faster fault isolation when it matters most.
• 90A at 240V, 3-pole configuration: ideal for higher-current branches and three-phase circuits, delivering targeted protection without oversizing the panel equipment.
• OEM compatibility: designed to fit seamlessly with matching Siemens load centers and panelboards, simplifying retrofit projects or new installations.
• Versatile application: suitable for residential, commercial, and light industrial settings where reliable branch circuit protection is essential.

What problems this breaker solves

The B390H guards your electrical system against overcurrent and short-circuit events, helping prevent wiring insulation damage and cascading equipment failures. In a three-pole setup, it protects 3-phase feeders and associated loads—think HVAC, lighting, outlets, and small motors—while preserving panel balance and safety.

Technical snapshot

• Manufacturer: Siemens
• Part Number: B390H
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 90A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Applications: Branch circuit overcurrent and short-circuit protection

Practical installation insights

For best results, pair this breaker with compatible Siemens OEM load centers and panelboards. Verify panel compatibility for a 3-pole, 240V installation and follow standard safety procedures during retrofit or new-build projects. The bolt-on design and robust trip mechanism are built to withstand regular panel servicing, reducing maintenance interruptions and helping you keep critical systems online.