Siemens Q390H - 90 A, 240 V, 3-Pole Plug-In Circuit Breaker | AmpState

Siemens Q390H - 90A, 240V, 3-Pole Plug-In Molded Case Circuit Breaker is engineered for reliable protection in residential, commercial, and light industrial electrical systems. When you need fast, secure protection for your branch circuits and motor loads, this plug-in unit delivers.

Fast, tool-free plug-in installation

Plug-in connection enables quick replacement and minimal downtime in panelboards and loadcenters. This is especially valuable for service upgrades, routine maintenance, or when replacing aging breakers in busy electrical rooms.

Precise protection you can count on

The thermal-magnetic trip unit delivers stable, repeatable protection against both overcurrent and short circuits. It responds quickly to short-circuit events while reducing nuisance trips from normal load fluctuations, helping protect wiring and connected equipment.

Designed for compatibility and reliability

With OEM load center and panelboard compatibility, the Q390H installs where Siemens systems are used, ensuring predictable performance and straightforward field replacements. Its 3-pole configuration is ideal for three-phase circuits at 240V, supporting a range of equipment beyond basic lighting circuits.

Ideal applications

• Residential service panels requiring robust 90A protection for multi-wire branch circuits and subpanels
• Commercial panels supporting HVAC, pumps, and lighting feeders
• Light industrial panel boards feeding small motors and control circuits

Key specifications at a glance

• Amperage rating: 90A
• Voltage rating: 240V
• Poles: 3 (three-pole)
• Mounting: Plug-in molded case
• Type: Thermal-magnetic molded case circuit breaker
• Manufacturer: Siemens
• Part number: Q390H

Whether you’re upgrading an older Siemens panel or stocking your service van for quick field replacements, the Siemens Q390H delivers the protection and reliability your electrical systems depend on. From the workshop to the job site, AmpState brings you genuine Siemens components that fit seamlessly into your panelboards and loadcenters, with performance you can trust.