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Siemens 3VA9978-0AA12 Auxiliary Switch Contacts for 3VA4/5/6

Siemens auxiliary switch with HQ changeover contacts (7mm) for 3VA4/5/6 MCCBs.

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ManufacturerSiemens

Part number3VA9978-0AA12

Contact Type Auxiliary Switch Changeover

Contact Rating HQ (7 mm)

Compatible With Siemens 3VA4/5/6 Series MCCBs

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Auxiliary changeover contacts Type HQ (7 mm) Compact design For Siemens 3VA4/5/6 MCCBs Enables status signaling

Product description

The Siemens 3VA9978-0AA12 is an accessory component featuring auxiliary switch changeover contacts of Type HQ, with a narrower 7 mm width. This accessory is designed for compatibility with Siemens 3VA4, 3VA5, and 3VA6 series molded case circuit breakers (MCCBs). It provides essential signaling contacts that reflect the operational status of the main circuit breaker.

This type of auxiliary switch is vital for applications requiring compact signaling solutions within control systems. It is frequently employed in distribution boards, control cabinets, and automated machinery for status monitoring, alarm generation, and interlock logic. Industries such as manufacturing, building services, and infrastructure rely on these components for reliable system oversight.

Stanlo Automation, a veteran-owned business, is your go-to source for quality surplus industrial automation parts, including the Siemens 3VA9978-0AA12. We are committed to providing reliable components and efficient service to keep your automation systems running at peak performance. Choose Stanlo for your critical parts needs.

Technical specifications

Contact Type	Auxiliary Switch Changeover
Contact Rating	HQ (7 mm)
Compatible With	Siemens 3VA4/5/6 Series MCCBs

Common applications

Compact control panels

Distribution boards

Automated machinery

Status monitoring

Interlock circuits

Compatible systems

Siemens 3VA4 Series MCCBs Siemens 3VA5 Series MCCBs Siemens 3VA6 Series MCCBs

Also known as

Siemens 3VA9978-0AA12 aux switch Siemens HQ auxiliary contacts 3VA4/5/6 breaker HQ contacts Siemens 7mm auxiliary switch

Replaces / compatible with

This auxiliary switch is an accessory for the Siemens 3VA4, 3VA5, and 3VA6 series circuit breakers and is not a direct replacement for other components.

Technical note

Expert tip

The 7 mm width of the Type HQ contacts in the 3VA9978-0AA12 is ideal for applications where space is limited within the accessory mounting area of the 3VA4, 3VA5, and 3VA6 circuit breakers.

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Frequently asked questions

What is the difference between the 3VA9978-0AA11 and 3VA9978-0AA12?

The main difference is the contact type and size: the 3VA9978-0AA11 features Type HP (14 mm) contacts, while the 3VA9978-0AA12 features Type HQ (7 mm) contacts. Both are auxiliary switches for 3VA4/5/6 circuit breakers.