Automatic Transfer Switch (ATS Panel)
Specification
Rating: 32A to 4000A (3-phase + N)
Voltage: 415V / 400V AC 3-phase (other voltages on request)
Transfer time (open): 100–300ms typical
Transfer time (closed): <20ms (synchronisation check required)
Mains monitoring: Undervoltage (adjustable), overvoltage, phase failure, frequency
Generator start: Volt-free contact output to generator AMF panel
Retransfer delay: Adjustable 5–30 minutes (allows generator stabilisation)
Brands: Siemens, Schneider Electric, ABB, Eaton
FAT: Transfer sequence simulation, timing verification, protection relay test
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Automatic Transfer Switch (ATS) Panels in UAE Generator & Mains Changeover, 32A to 4000A
Automatic Transfer Switch (ATS) panels provide seamless changeover of electrical supply from the normal utility mains to a standby generator or between two independent utility feeders on detection of mains failure, undervoltage, or frequency deviation. They are a critical component of any facility requiring continuous power for safety systems, data centres, hospitals, process plant, or critical infrastructure. Team Switchgear and Control LLC designs and manufactures custom ATS panels from our Dubai facility, rated from 32A to 4000A, using Siemens, Schneider Electric, ABB, and Eaton switching devices.
ATS Types We Supply
Open Transition ATS (Break-Before-Make): The most common type load is briefly disconnected from both sources during changeover. Transfer time typically 100–300ms. Suitable for most generator backup applications where a brief power interruption is acceptable.
Closed Transition ATS (Make-Before-Break): Both sources are momentarily paralleled during transfer to achieve a zero-interruption changeover. Requires synchronisation check relay to verify voltage, frequency, and phase angle before closing. Required for sensitive loads and for paralleling with the utility grid.
Contactor Type ATS: Compact, cost-effective format for ratings up to 250A. Siemens SIRIUS, Schneider TeSys, or ABB contactors with mechanical and electrical interlock. Suitable for small commercial and residential generators.
Motorised Circuit Breaker ATS: For ratings from 250A to 4000A using motorised MCCBs or ACBs. Positive make-break action, higher short-circuit withstand, and integral protection functions.
Applications
- Data centres and server rooms UPS and generator backup changeover
- Hospitals and healthcare essential and non-essential supply changeover per HTM standards
- Hotels and commercial buildings generator backup for life safety and critical loads
- Industrial process plant maintaining critical drives and control systems during mains failure
- Telecommunications base station and network exchange backup power
How long does it take for an ATS panel to transfer to generator?
For an open transition ATS, the total time from mains failure to full load on generator is typically 10–15 seconds this comprises the mains failure detection and confirmation delay (3–5 seconds), generator start and build-up time (5–10 seconds), and the mechanical transfer time of the switching device (100–300ms). For loads that cannot tolerate this interruption, an online UPS system provides seamless power during the generator start period while the ATS handles the longer-term generator connection.
Can the ATS panel automatically return to mains supply after the generator?
Yes. Retransfer from generator back to mains is a standard function. When the mains supply is restored and stable (within voltage and frequency tolerances for an adjustable confirmation period typically 5–15 minutes), the ATS automatically returns the load to mains and sends a cool-down signal to the generator. The confirmation delay prevents premature retransfer if the mains supply is unstable during a brownout. All timing parameters are configurable during commissioning.