Siemens 3VA9978-0AA22 3A Switch, Auxiliary Switch | AmpState

Meet the Siemens 3VA9978-0AA22 — a compact 3A switch designed as an auxiliary switch for reliable manual control and switching functions in industrial control panels. Built for environments where a direct part-number match matters, this unit ensures seamless integration with Siemens automation ecosystems and minimizes downtime during replacements.

Why this auxiliary switch stands out

• Exact part-number fit: 3VA9978-0AA22 is purpose-built to drop into Siemens control setups, streamlining ordering, stocking, and repairs for maintenance teams and panel builders.
• 3 A switching capability: Ideal for low-power control circuits, signaling, and manual overrides without overloading the circuit.
• Reliable manual control: A straightforward auxiliary switch that provides immediate operator interface for on/off signaling and interlock scenarios.
• Low-friction replacement: Great for spare inventories—reduces search time and ensures quick swaps when service windows are tight.
• AmpState availability: Easily purchased through AmpState, with assistance available to confirm compatibility and fitment if needed.

Who should consider this part

• Maintenance teams stocking essential Siemens accessories for fast repairs.
• Panel builders seeking components with exact part-number compatibility to ensure repeatable builds.
• Plant engineers needing dependable auxiliary signaling for control logic and manual override functions.

Practical applications and scenarios

• Manual control overrides in Siemens-based control panels where a quick, tactile switch is required.
• Auxiliary signaling to PLCs or control relays to convey a specific status or interlock condition.
• Replacement in aging assemblies where the original auxiliary contact block is worn or out of spec.

How it fits into your procurement and maintenance strategy

Choosing a direct part-number match like the 3VA9978-0AA22 reduces the risk of fit issues, wiring mismatches, and compatibility surprises during maintenance outages. It keeps your spare inventory lean while ensuring you can perform precise, quick swaps that maintain process uptime.

Need help confirming compatibility?

We can help verify fitment against your Siemens equipment. Message us for guidance on part-number matching and compatibility checks to ensure a seamless replacement in your control panel.

Specifications at a glance

• Manufacturer: Siemens
• Part Number: 3VA9978-0AA22
• Product Type: Switch (Auxiliary Switch)
• Amperage: 3 A