Automatic Transfer Switches (ATS) for Standby Power
An automatic transfer switch (ATS) detects loss of utility power, signals the generator to start, and transfers the load to generator power, then retransfers when utility returns. ATS units, such as the Eaton ATC-300 and ATC-900 series, are rated up to about 4000A and offer open, closed, or soft transition and bypass-isolation options. Comp-Utility specs, installs, and services automatic transfer switches across Central Texas.
What We Provide
Our Capabilities
ATS Selection and Sizing
We size and specify the ATS, including transition type and bypass-isolation, for your standby power system.
Learn moreInstallation and Integration
We install and integrate the ATS with your generator and distribution and commission the transfer sequence.
Learn moreTransfer Testing and Maintenance
We perform NFPA 110 transfer testing and maintenance so the ATS transfers automatically and reliably.
Learn moreAutomatic Backup
The Switch That Brings Your Generator Online
The ATS is the device that makes standby power automatic: it senses a utility failure, starts the generator, transfers the load, and reverses the process when utility power is restored, all without human intervention.
Choosing the right transition type and sizing the ATS correctly are essential. Comp-Utility specifies, installs, tests, and maintains transfer switches as part of a reliable backup power system.
Key Specifications
| Attribute | Automatic Transfer Switch (ATS) |
|---|---|
| Function | Automatic utility-to-generator transfer |
| Current rating | Up to ~4000A |
| Voltage | Up to 600V |
| Transition types | Open, closed, or soft (delayed) transition |
| Representative products | Eaton ATC-300, ATC-900 series |
| Features | Bypass-isolation, programmable controller |
| Typical applications | Generator backup, emergency power systems |
Specifications reflect representative ATS products from our manufacturer partners; exact ratings and configurations vary. Contact us to confirm the current configuration for your project.
The Comp-Utility Difference
Why Comp-Utility?
Long-Standing Distribution Partner
As a long-standing distribution partner of Eaton, Schneider Electric, and Vertiv, we specify best-in-class systems and back them with factory-grade service.
Engineer-Owned and Operated
Comp-Utility is owned and operated by engineers, with licensed Texas Professional Engineers (P.E.) on staff. That rigor anchors every design, specification, and installation.
24/7 Emergency Response and Preventative Maintenance
Our technicians provide preventative maintenance programs and 24/7 emergency response, with rapid on-site dispatch across Central Texas when facilities need us most.
Turnkey, Single-Contract Partner
We sell, design, install, and maintain complete infrastructure end to end. One accountable team and one contract for power, cooling, distribution, and cabling.
Licensed, Certified & Recognized
We hold ourselves to the standards of the institutions we serve, from professional licensure and jobsite safety to the industry organizations that set the bar for mission-critical work.
Licensed Professional Engineers
State of Texas (TBPE)
OSHA 30 Certified
Field Technicians
AFCOM Member
Data center industry association
7x24 Exchange Member
Mission-critical infrastructure
Frequently Asked Questions
What is an automatic transfer switch (ATS)?
An automatic transfer switch monitors the utility source and, on loss of power, signals the standby generator to start and transfers the load to it, then retransfers to utility and shuts the generator down when normal power returns. It makes backup power automatic, requiring no manual intervention during an outage. ATS units are central to any standby power system.
What transition types are available?
ATS units offer open transition (break-before-make, with a brief interruption), closed transition (make-before-break, seamless, briefly paralleling sources), and soft or delayed transition. The right type depends on whether a momentary break is acceptable, whether a UPS covers the gap, and utility requirements. Comp-Utility recommends the transition type for your loads and utility rules.
What is bypass-isolation on an ATS?
A bypass-isolation ATS allows the transfer switch to be bypassed and isolated for maintenance or testing without dropping the load, by manually routing power around the switch. This is valuable for critical facilities that cannot tolerate downtime to service the ATS. Comp-Utility specifies bypass-isolation switches where maintainability is a priority.
How do I size an ATS?
An ATS is sized to the full load current it must carry, the system voltage, and the transition and features required, with appropriate headroom. It must handle the entire load on either source. Comp-Utility calculates the load and specifies the ATS rating, transition type, and features to match your generator and distribution.
What is NFPA 110 transfer testing?
NFPA 110 is the standard for emergency and standby power systems. Transfer testing verifies that on loss of normal power the generator starts and the ATS transfers the load within the required time, then retransfers and shuts down correctly when utility returns. Comp-Utility performs and documents this testing for compliance and reliability.
Why would an ATS fail to transfer?
Common causes include controller faults, control-power or wiring issues, a generator that fails to start or reach the right voltage and frequency, or mechanical problems in the switch. If your ATS will not transfer, call (512) 346-0999; Comp-Utility troubleshoots the controller, generator signaling, and switch to restore automatic operation.
Can you upgrade or replace an existing ATS?
Yes. We service, repair, upgrade, and replace transfer switches, including adding bypass-isolation or changing transition schemes where requirements change. We assess the existing equipment and recommend repair, upgrade, or replacement based on condition and your needs. Comp-Utility handles the work as part of a turnkey standby power project.
Who installs and services ATS units in Central Texas?
Comp-Utility specs, installs, tests, and maintains automatic transfer switches across major brands throughout Central Texas, including NFPA 110 transfer testing and 24/7 emergency response. Engineer-owned since 1992. Call (512) 346-0999 or email sales@comp-utility.com.