Automatic Transfer Switch Transition Types

Automatic transfer switches (ATS) are critical for ensuring uninterrupted power during outages, but not all switches handle the transition between power sources the same way. Understanding automatic transfer switch transition types—open, closed, and delayed—helps you select the right solution for your home, business, or industrial facility. In this guide, we’ll break down each transition type, their pros and cons, and explain why CNC offers reliable, adaptable ATS solutions tailored to diverse needs.

What Are Automatic Transfer Switch Transition Types?

The “transition type” refers to how an ATS shifts loads from the primary power source (e.g., the grid) to the backup source (e.g., a generator). The choice depends on your power sensitivity, equipment requirements, and budget.

1. Open Transition (Break-Before-Make)

How It Works:

The ATS briefly disconnects the load from the primary source before connecting to the backup source, causing a momentary power interruption (typically 1–3 seconds).

Pros:

Simple & Cost-Effective: Lower upfront cost, ideal for non-critical systems.

Compatibility: Works with most standard generators.

Cons:

Power Interruption: Not suitable for sensitive equipment like medical devices or servers.

Best For:

Residential homes with basic backup needs.

Small businesses where brief outages are acceptable.

CNC Solutions:

CNC’s open transition ATS models are budget-friendly and easy to install, making them a go-to for homeowners and small offices.

2. Closed Transition (Make-Before-Break)

How It Works:

The ATS overlaps the connection between the primary and backup sources, ensuring no interruption in power supply.

Pros:

Seamless Transition: Zero downtime for critical systems (hospitals, data centers).

Reduced Stress: Prevents voltage spikes that damage sensitive electronics.

Cons:

Higher Cost: Advanced synchronization technology raises the price.

Complex Installation: Requires compatible generators and professional setup.

Best For:

Healthcare facilities, server rooms, and manufacturing plants.

Applications with UPS (uninterruptible power supply) systems.

CNC Solutions:

CNC’s closed transition ATS units feature advanced synchronization tech, ensuring smooth transfers for mission-critical operations.

3. Delayed Transition

How It Works:

A hybrid approach where the ATS disconnects from the primary source, waits for a programmed delay (e.g., 5–10 seconds), and then connects to the backup.

Pros:

Generator Protection: Gives generators time to stabilize before loading.

Cost Balance: More affordable than closed transition but minimizes equipment stress vs. open transition.

Cons:

Short Outage: Power is interrupted during the delay period.

Best For:

Facilities with motor-driven equipment (e.g., HVAC systems, pumps).

Scenarios where generator stability is a priority.

CNC Solutions:

CNC’s delayed transition switches are popular in industrial settings, offering a practical balance of cost and performance.

How to Choose the Right Transition Type

Consider these factors when selecting an ATS:

1.Criticality of Load:

Critical (e.g., hospitals): Closed transition.

Non-critical (e.g., lighting): Open/delayed transition.

2.Budget:

Open transition is cheapest; closed transition is premium.

3.Generator Type:

Closed transition requires inverter or synchronous generators.

Why CNC’s ATS Solutions Stand Out

CNC designs automatic transfer switches that prioritize flexibility, durability, and value:

1. Versatile Product Range

Residential ATS: Open transition models for homes.

Industrial ATS: Closed/delayed transition for factories and data centers.

Smart ATS: Remote monitoring via app for real-time alerts.

2. Built to Last

Weatherproof Enclosures: Rated for indoor/outdoor use in harsh climates.

Certified Safety: Complies with international electrical standards (specific marks vary by region).

3. Cost Efficiency

CNC’s ATS units are priced competitively, often 20–30% below premium brands, without compromising on core reliability.

4. Fast, Flexible Support

Regional Availability: Lead times vary by location but are optimized through local warehouses.

Custom Configurations: Tailor delays, load priorities, and sync settings.

Real-World Applications

Hospital in Texas: CNC’s closed transition ATS keeps MRI machines and life-support systems online during grid failures.

Manufacturing Plant: Delayed transition switches protect conveyor motors from abrupt power shifts.

Homeowner with Solar: Open transition ATS pairs with a backup generator for storm-related outages.

Choosing the right automatic transfer switch transition type ensures your backup power system operates safely and efficiently. While closed transition suits critical infrastructures, open and delayed transitions offer practical savings for less sensitive setups.