An Automatic Transfer Switch is the unsung hero of any backup power system. Most people never think about it until the moment it fails. Here is why that is a mistake.
When mains power fails, your generator does not simply start and take over. There is a critical piece of equipment in between: the Automatic Transfer Switch. The ATS monitors incoming mains supply, detects a failure, signals the generator to start, and then transfers the electrical load from mains to generator once the set is running at stable voltage and frequency.
It then monitors for mains restoration, transfers the load back, and signals the generator to cool down and shut off. Every one of those steps must happen in the right sequence, at the right time, with the right tolerances. A poorly specified or incorrectly commissioned ATS can cause more damage than no ATS at all.
The most common ATS failures are not mechanical. They are commissioning failures. Transfer time settings that are too aggressive cause voltage spikes. Incorrect voltage sensing thresholds cause nuisance transfers or missed failures. Inadequate testing means the first real power cut is also the first real test of the system.
EA Power Systems commissions every ATS as part of a full system test, not as a standalone component. Transfer times, voltage windows, frequency tolerances, and load sequencing are all verified under real conditions before any system is handed over.
Not all ATS units are equal. Open transition switches are simpler and lower cost, but they create a brief interruption during transfer. Closed transition switches allow a momentary parallel operation, eliminating the interruption entirely. For sensitive loads such as data centres and hospitals, closed transition is often the only acceptable option.
Your generator may be perfectly sized and impeccably maintained. But if the ATS is wrong, none of that matters. EA Power Systems specifies, supplies, and commissions ATS equipment as an integral part of every power solution, not as an afterthought.
