Siemens B390 - 90 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

The Siemens B390, available from AmpState, is a 90A, 240V, 3-pole bolt-on molded case circuit breaker designed to deliver dependable branch‑circuit overcurrent and short‑circuit protection in panelboards and loadcenters. Built to endure the rigors of daily electrical distribution, it pairs Siemens reliability with a secure mounting system that stays put in demanding environments.

• Bolt-on mounting: secure, vibration‑resistant bus connection for consistent electrical performance.
• Thermal‑magnetic trip unit: provides stable, repeatable protection against overloads and short circuits.
• 3‑pole, 90A, 240V: ideal for balanced three‑phase feeders or multi‑branch configurations in distribution panels.
• OEM compatibility: designed to work with matching Siemens loadcenters and panelboards for a seamless upgrade or replacement.
• Versatile applications: suitable for residential, commercial, and light industrial electrical distributions.

Why this matters: a bolt-on design reduces installation time and ensures a solid connection, while the thermal‑magnetic trip delivers dependable protection that minimizes nuisance trips during normal operation and reliably clears faults when they occur. The 90A rating makes it suitable for protecting feeder circuits or branch circuits that demand higher current capacity without sacrificing safety.

Applications and compatibility: use in Siemens OEM panelboards and loadcenters where a 90A, 3‑pole, 240V circuit breaker is required. This unit is intended for branches that demand robust overcurrent protection and short‑circuit interruption, from residential panels to light commercial distribution boards.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: B390
• Type: Thermal‑magnetic molded case circuit breaker
• Amperage rating: 90A
• Voltage rating: 240V
• Poles: 3
• Mounting style: Bolt‑on
• Applications: Branch circuit overcurrent and short‑circuit protection

Designed for electrical professionals and facility managers seeking a reliable, install‑friendly protection solution that aligns with Siemens panelboard ecosystems. When upgrading or maintaining panels, the B390 offers precise protection characteristics, predictable trip behavior, and a proven track record in demanding environments.