Siemens Q390 90A 3P Circuit Breaker, Plug-On | AmpState

Introducing the Siemens Q390 90A 3P Plug-On Circuit Breaker — a purpose-built protective device designed for panelboards, load centers, and electrical distribution systems. Its plug-on design enables fast, secure mounting, helping minimize downtime during panel upgrades, replacements, or new installations.

With a 90 amp rating and three poles, the Q390 delivers reliable three-phase protection for demanding commercial and light-industrial applications. When you need a direct part-number match for seamless interchangeability, this Siemens component provides the compatibility and confidence your team relies on.

Why this breaker stands out

• Direct part-number match — precision-fit compatibility with compatible Siemens panels reduces installation guesswork and errors.
• Plug-On convenience — snap-in mounting simplifies replacements and minimizes wiring concerns in busy electrical rooms.
• Three-phase protection — ideal for 3-phase circuits powering motors, HVAC systems, and multi‑load environments.
• Reliable Siemens engineering — designed to perform consistently under distribution loads, delivering predictable tripping behavior.

Ideal use cases

• Maintenance and spare inventory for panel builders and service teams needing a ready-to-install, exact-fit breaker.
• Replacement in existing Siemens panelboards and load centers requiring a 3P, 90A protective device.
• Three-phase distribution in commercial spaces, data centers, small to mid-size industrial setups, and equipment rooms.

If you’re unsure about compatibility, AmpState offers direct assistance to confirm fit. Message us with your panel model or part-number context, and we’ll help verify that the Q390 is the right match for your installation.

Order the Siemens Q390 90A 3P Plug-On Circuit Breaker from AmpState today to streamline maintenance workflows and ensure reliable, compliant protection for your electrical distribution network.