Schaltbau DC Contactors, Load Breaking, Power Switching

The Problem:

In DC systems, switching and interruption are not forgiving. Unlike AC, DC current does not naturally pass through zero, which means arcs persist unless they are actively controlled.

Engineers often encounter issues such as:

Accelerated contact wear due to sustained DC arcing
Unpredictable failure modes in sealed or gas-filled contactors
Difficulty interrupting high current at elevated DC voltages
Challenges supporting bidirectional power flow
Poor visibility into the contactor condition over time
Late-stage design changes after field or test failures

These problems rarely appear on paper, but they surface quickly during commissioning, validation, or long-term operation.

Design Concern	How Schaltbau Helps	What Dynamic Adds
Breaking high DC current	Engineered arc suppression and contact design	Helps you choose the right series & approach
Long duty cycles	Robust contact materials & design	Interprets performance vs needs
Safety & compliance	IEC-rated components with feedback options	Aligns selections with safety targets
Reliability over time	Proven in demanding real systems	Provides pattern-based guidance, not guesswork
Early design decisions	Purpose-built solutions	Early technical review and risk discussion

DC is not AC with a different rating

Many contactors on the market are based on AC designs with modified ratings. While this approach can work at lower energy levels, it becomes risky as voltage, current, or duty cycle increases.

Without zero crossings:

Arcs persist longer and release more energy
Heat buildup becomes a limiting factor
Contact geometry and materials matter far more than nominal ratings

Sealed designs are not always safer

Sealed or gas-filled contactors are often assumed to be safer. In high-energy DC interruptions, sealing can trap heat and arc energy, limiting breaking capacity and hiding wear. During a short circuit, rapid gas heating can trigger an overpressure event that may cause the device to rupture under fast-fault conditions.

Failure behavior matters

In high-energy DC systems, how a contactor fails is often more important than its advertised lifespan. Engineers need devices with predictable, inspectable behavior that supports maintenance and risk mitigation.

This is where application knowledge becomes just as important as the component itself.

Schaltbau c310 contactor

AC and DC contactors up to 3,000V and 2,000A

Building upon our experience in railway technology, Schaltbau produces highly reliable, outstanding contactors for all fields of use in which a load circuit has to be switched on and disconnected securely. Designed to IEC specifications, our wide variety of AC and DC contactors in stock range from contactors for low-voltage devices, such as batteries, through to high-voltage power contactors up to 3,000 V and 1,100 A.

Snap-action Switches

Snap-action switches, often called microswitches or limit switches, are electromechanical devices with a unique design that enables rapid actuation. These switches operate on a “snap-action” mechanism, meaning they quickly change state when a threshold of force is applied to the actuator. This distinctive characteristic makes them ideal for safety applications that require swift, precise switching.

Connectors

Connectors must ensure reliable transmission of energy and signals – coping with high voltages, harsh environments, and the rough conditions of rail traffic. Connectors from Schaltbau are specifically designed to meet these requirements: Where the safety and health of human beings depend on technology, as in transportation, mechanical engineering, lighting, food processing, battery charging, mining, or offshore operations, the rugged, heavy-duty connectors from Schaltbau are the first choice.

Key engineering advantages

Schaltbau DC contactors are engineered specifically for high-energy DC applications that require controlled interruption, long service life, and predictable behavior.

Rather than sealing the arc inside the device, Schaltbau employs open-air, arc-chute designs that actively manage and extinguish arcs under demanding conditions.

High breaking capacity at elevated DC voltages and currents
Proven arc management using open-air arc chute technology
Support for bidirectional power flow architectures
Predictable wear patterns that can be inspected and understood
Long service life in applications with frequent switching or high fault energy

These designs are well-suited for systems where reliability, safety, and maintainability cannot be compromised.

Additional Insight

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The Problem:

DC is not AC with a different rating

Sealed designs are not always safer

Failure behavior matters

PRODUCTS

AC and DC contactors up to 3,000V and 2,000A

Snap-action Switches

Connectors

Key engineering advantages

Trusted by Engineers Who Want More Than Parts

Ask better questions earlier in the design process

Avoid costly redesigns

Peace of mind that what's been specified will work as intended

What a Conversation Looks Like:

You’ll walk away with clarity on:

Additional Insight

Let's get in touch

The Problem:

DC is not AC with a different rating

Sealed designs are not always safer

Failure behavior matters

PRODUCTS

AC and DC contactors up to 3,000V and 2,000A

Snap-action Switches

Connectors

Key engineering advantages

Trusted by Engineers Who Want More Than Parts

Ask better questions earlier in the design process

Avoid costly redesigns

Peace of mind that what's been specified will work as intended

What a Conversation Looks Like:

You’ll walk away with clarity on:

Additional Insight