Siemens CQD370 - 70 A, 480 V, 3-Pole Circuit Breaker | AmpState

Siemens CQD370 is a rugged 3-pole molded case circuit breaker designed to deliver dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. With a 70-amp rating and a 480-volt capacity, this unit is purpose-built for three-phase electrical systems found in commercial and light industrial environments, while still being suitable for residential projects that demand higher power distribution safety.

Designed to fit your existing OEM panel infrastructure, the CQD370 combines compact form with reliable protection. Its molded case construction optimizes panel space, helping you configure distribution layouts more efficiently without sacrificing protection or performance.

Key features that matter in real-world installations

• Compact molded case design for efficient use of panel space and easier wiring access during installation and replacement.
• Thermal-magnetic trip unit delivers stable, repeatable protection by responding appropriately to overloads (thermal) and short circuits (magnetic), reducing nuisance tripping and enhancing system reliability.
• 3-pole configuration ideal for 3-phase, 4-wire systems commonly used in commercial spaces and demanding equipment rooms.
• OEM panel compatibility engineered to integrate with matching Siemens OEM load centers and panelboards, ensuring proper fit and coordinated protection characteristics.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: CQD370
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 70 A
• Voltage Rating: 480 V
• Number of Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

What makes this breaker the right choice?

When you're designing or upgrading a panel, reliability and compatibility are as important as ratings. The CQD370 offers a precise protection profile for three-phase feeders and branch circuits at 480 V, helping prevent equipment damage and fire risk from overloads and faults. The thermal-magnetic trip mechanism is engineered for consistent performance across varying ambient temperatures and loading conditions, reducing the likelihood of unpredictable trips in everyday use.

Ideal for facilities where space is at a premium and electrical systems demand robust protection, the CQD370 is a practical choice for commercial offices, retail spaces, light manufacturing, and service installations. It also serves well in residential projects that require higher-capacity protection for specialized equipment or multi-load configurations.

Practical tips for installation and operation:

• Verify panelboard compatibility with the Siemens CQD370 and ensure the trip characteristics align with your protection plan.
• Use the 3-pole configuration to safeguard all phases in a 3-phase distribution to reduce unequal loading and potential fault paths.
• Plan for module replacement with a matching CQD370 to streamline maintenance and minimize downtime during service events.
• Document the rating and wiring scheme on the panel cover for quick future reference and compliance checks.