Schneider Altistart ATS22 vs ATS480: Which to Choose

Which Schneider Altistart soft starter fits your motor — ATS22 or ATS480? The ATS22 is Schneider's standard-tier soft starter, offering voltage ramp plus an open-loop torque-control mode up to roughly 590 A, sized for straightforward pump, fan and conveyor duty. The ATS480 is the current flagship: closed-loop Torque Control System (TCS), a graphic display, embedded Modbus, and full motor-plus-starter thermal protection, scaling to roughly 1200 A. The right pick depends on control precision, communication needs, motor size, and how much the load punishes a plain voltage ramp. Below: control method, bypass and heat handling, communication, current range, protection depth, and where the ATS480's extra cost actually pays off.

Control Method: Open-Loop Torque Estimation vs Closed-Loop TCS

Both starters ramp voltage rather than switching the motor straight across the line. The ATS22 gives voltage ramp plus a torque-control mode that estimates motor torque from measured current and voltage — open enough for most pump and fan curves that behave the same way every start. The ATS480 runs a closed-loop Torque Control System that measures actual delivered torque and adjusts SCR firing angle in real time, holding a linear speed rise even as load conditions shift mid-start.

What we see in the field: on a centrifugal pump with a stable static head, the ATS22's estimated torque control tracks close enough that the difference is academic. On a load with variable static head — a pump filling against a rising tank level, for instance — the ATS480's closed loop corrects for it start to start. The ATS22 does not adjust once the ramp begins.

This square-law relationship is why torque control matters more as load inertia rises. At 60% voltage a motor gives about 36% of its DOL torque — fine for a fan, tight for a loaded conveyor. The ATS22's estimation is adequate when the load torque curve repeats predictably start after start; the ATS480's closed loop earns its keep when it does not.

Built-In Bypass and Heat Handling

Both ranges offer built-in bypass on most references, closing a contactor across the SCRs once the motor reaches full speed. Bypassed, the SCRs stop conducting and stop dissipating the roughly 1-1.5 W per amp per phase they generate while running the ramp, so the enclosure runs cooler and needs no derating for continuous run current. See our soft starter bypass contactor explanation for the full mechanism.

Where the two differ is thermal modeling after bypass. The ATS480 keeps tracking starter and motor temperature through its own thermal model even while bypassed, feeding into too-many-starts and stall protection. The ATS22's bypass is simpler: once bypassed, protection reverts largely to the motor's own thermal relay or an external overload block.

Communication and HMI

The ATS22 ships with a basic keypad or remote potentiometer on most references — enough to set ramp time, initial voltage, and current limit, with no fieldbus by default on the base range. The ATS480 has a graphic display as standard and embedded Modbus, so ramp curves, fault history, and motor current can be read and adjusted from a PLC or SCADA screen without opening the panel.

Not a cosmetic difference. A plant running forty soft-started motors wants fault codes on the SCADA screen, not a technician walking the line with a multimeter. A single-motor pump skid in a mechanical room rarely needs it.

Retrofits raise the same question from the other direction. Swapping a fault-prone ATS22 into an ATS480 on a motor that already reports through a PLC removes a manual step from every trip investigation — the operator sees which protection function tripped instead of just a tripped output relay. On a standalone starter with no upstream SCADA link, that visibility goes unused, and the ATS22's simpler keypad setup is faster to commission on-site.

Current Rating and Motor Size Range

The ATS22 covers roughly up to 590 A on its largest frames, enough for most motors to a few hundred kW at 400 V. The ATS480 extends to about 1200 A class, reaching large pumps, compressors and mill drives that sit outside the ATS22's range entirely. If the motor's full-load current exceeds the ATS22's top frame, the ATS480 is not a preference — it is the only option in the family. See our soft starter sizing guide for the full selection sequence, and AC-53a/AC-53b duty sizing for the starts-per-hour limits that apply to both ranges.

Motor and Starter Protection Depth

The ATS22 covers the basics: overload via I²t, phase loss, and a locked-rotor timer. The ATS480 adds phase-sequence detection, undercurrent (useful for dry-run detection on pumps), shorted-SCR detection, and a fuller thermal model tracking motor and starter temperature independently. On a critical process pump, that extra layer — an undercurrent trip on a dry-run condition, for instance — can be the difference between a nuisance shutdown and a burned seal.

Not every application needs it. A non-critical exhaust fan with a simple downstream overload relay rarely justifies the ATS480's protection depth on cost alone.

Shorted-SCR detection deserves a separate mention. A shorted thyristor on the ATS22 typically shows up downstream as an overcurrent trip, a blown fuse, or in the worst case a phase running unregulated into the motor — the starter itself does not flag the SCR as the cause. The ATS480 checks conduction on each SCR and reports the failed device directly, cutting diagnosis time from an afternoon of continuity checks to a fault code on the display.

Comparison: ATS22 vs ATS480

For a three-way view including Siemens and ABB flagship units, see our ABB PSTX vs Schneider ATS480 vs Siemens 3RW55 comparison. For the underlying control-mode distinctions across all brands, see voltage ramp, current ramp and torque control soft starters.

Conclusion

Start with current: if the motor's FLC sits above the ATS22's top frame, the ATS480 is the only Altistart option. Below that threshold, the decision turns on load behavior and visibility — a fixed pump or fan curve rarely needs the ATS480's closed-loop control, but a variable-head pump, a large conveyor, or a process motor where a dry-run trip matters usually does. Both ranges sit within the same soft starters category on the standards side, since AC-53a/AC-53b duty and IEC 60947-4-2 apply to each, so the sizing method does not change between them. For the full selection sequence across brands, see our soft starter selection guide.