ATSE for Data Center Power Switching
In a data center the critical path is usually the UPS, not the changeover. ATSE equipment belongs upstream of the UPS on utility-to-generator transfer, and on the mechanical and support loads that are not UPS protected. Keeping that boundary clear is what prevents avoidable load drops during a utility event.
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MOTE Electric ATSE equipment for data center projects is tested to IEC 60947-6-1 and available from 100A to 3200A.
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Utility-to-generator changeover at 2000A and above is supplied in PC class with upstream protection handled in the coordination study.
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Transfer delay is adjustable per board so mechanical loads do not step the generator beyond its capacity.
Which loads need changeover
Group the boards by the loads they serve, then read the tolerated interruption from the most sensitive load on that board.
| Load | Tolerated Interruption | Notes |
|---|---|---|
| UPS input (utility / generator) | Generator side commonly 10 s – 30 s | UPS carries the IT load; ATSE transfers the rectifier input |
| Chillers and cooling plant | ≤ 15 s – 30 s | Large motor loads — verify restart current and staging |
| Cooling pumps and fans | ≤ 15 s | Essential mechanical board with 3P changeover |
| Lighting and technical rooms | ≤ 5 s | Small frame changeover at sub-board level |
| Fire and life safety systems | Meets local life safety rule | Dedicated essential board |
| Office and general services | Not time critical | Deferred transfer to protect generator capacity |
Typical ATSE configuration
Ratings, poles, class and delay settings commonly used on each board type.
| Board | Current Rating | Poles | Class | Transfer Time Setting |
|---|---|---|---|---|
| Utility-to-generator main | 2000A – 3200A | 3P / 4P | PC | 1.5 s – 15 s |
| UPS input changeover | 1000A – 1600A | 3P / 4P | PC / CC | 1 s – 10 s |
| Mechanical essential board | 400A – 800A | 3P | PC / CC | 0.8 s – 5 s |
| Technical room sub-board | 100A – 320A | 3P / 4P | CC | 0.5 s – 3 s |
What to settle before the order
Keep the changeover upstream of the UPS
The UPS should remain the ride-through element for the IT load. Placing transfer switching upstream keeps the changeover out of the critical path and avoids nuisance transfers.
Match mechanical load restart to generator capacity
Chillers and pumps draw high restart current. Staging and delayed transfer protect the generator from a step load it cannot accept.
Define the acceptable interruption per board
Not every board needs the shortest transfer time. Setting delay per board preserves generator capacity for the loads that genuinely need fast transfer.
Products used on these boards
Questions on this application
Where should an ATSE be placed in a data center supply?
Upstream of the UPS, on utility-to-generator transfer, and on mechanical and support boards that are not UPS protected. The UPS remains the ride-through device for the IT load.
What transfer time suits a data center main changeover?
Utility-to-generator transfer is commonly set between about 10 s and 30 s, which allows the generator to start and stabilise before the rectifier input transfers.
How do you avoid generator overload during transfer?
Stage the mechanical loads and set different delays per board, so chillers and pumps do not restart simultaneously with the IT support loads.
Does MOTE Electric provide coordinated switchgear for data centers?
Yes. Changeover assemblies can be supplied with the ATSE, bypass, control and signalling integrated in one assembly.
Continue with another sector
Ask for a configuration review
Send the board schedule and the interruption each board tolerates. We will return a class, rating and delay proposal.