Two of the most frequently confused Socomec product families are the ATyS automatic transfer switch and the SIRCO switch disconnector. They look similar in the catalogue, but they do completely different jobs: one switches sources automatically, the other isolates a circuit manually. Choosing the wrong one leaves you either without backup power when you need it, or paying for automation you do not need.
ATyS: Automatic Transfer Switching
The ATyS range monitors two power sources (mains and generator, or mains and UPS) and transfers the load between them without operator intervention. When the preferred source fails, the ATyS detects the loss, starts the changeover sequence, and switches the load to the healthy source. Features vary by model: adjustable voltage and frequency thresholds, transfer delay settings, and remote monitoring via communication modules.
Use ATyS when the load must stay powered through a source failure - typical in data centres, control rooms, HVAC plant and critical production equipment. See the ATyS 3X125A automatic transfer switch for a common panel-mounting version.
SIRCO: Manual Switch Disconnectors
The SIRCO range is a manually operated switch disconnector for isolation and load breaking. It has no electronics and no changeover logic: an operator turns the handle to open or close the circuit. SIRCO is widely used for maintenance isolation (lockable in the open position), for photovoltaic plants - the SIRCO MOT PV versions handle up to 1500 VDC - and as a cost-effective switching point in distribution boards.
Use SIRCO when you need manual isolation only and automation is not required - typically where safety during maintenance is the priority and the circuit is not subject to automatic source changeover. See the SIRCO MOT PV 4X1000A solar isolator as an example.
ATyS vs SIRCO: Which One Do You Need?
| Criteria | ATyS | SIRCO |
|---|---|---|
| Operation | Automatic (sensed changeover) | Manual (handle operation) |
| Typical use | Mains/generator or mains/UPS changeover | Maintenance isolation, PV plant switching |
| Load continuity | Maintained through failure (with delay) | Not automatic - manual reconnection |
| Electronics | Yes (voltage sensing, timers, comms) | None - purely mechanical |
| Cost | Higher | Lower |
The decision is simple: if a power failure must not stop your process, choose ATyS. If you only need safe manual isolation, choose SIRCO. For generator standby systems, ATyS is the standard pairing with the generator's automatic start controller.
Both families are available in the Switch Disconnectors & Transfer category. For a full overview of the Socomec range, see our Socomec Power Solutions guide. For pricing, stock and lead times on ATyS, SIRCO or any Socomec part, request a quote through our quote form and we will respond within 24 hours.
Frequently Asked Questions
What is the difference between Socomec ATyS and SIRCO?
The ATyS is a motorised automatic transfer switch (ATS) that switches between two sources automatically. The SIRCO is a manual changeover and isolation switch operated by hand. ATyS is for automatic source transfer; SIRCO is for manual isolation and changeover.
Is the ATyS a transfer switch or an isolator?
The ATyS is a transfer switch - it automatically transfers the load between two supplies. It also provides isolation when in the open position, but its primary role is automatic source transfer, typically with a motorised operator.
Can the SIRCO switch be motorised?
The SIRCO range is primarily manual, but motorised versions exist for remote operation. If you need fully automatic source transfer, the ATyS (or ATyS d/g for dual-supply with generator control) is the purpose-built choice.