ATS01N125FT Soft starter ATS01 25A 400B

Schneider Electric Altistart 01 (ATS01) — ultra-compact soft starters for simple machinery

The Schneider Electric Altistart 01 (ATS01) series is a classic, field-proven solution for soft starting low-power asynchronous induction motors from 0.37 to 15 kW. The prime advantage of this line is its exceptional compactness (frame width of just 23 or 45 mm) and straightforward installation. The series is divided into two functional groups: ATS01N1 devices control a single phase (acting as torque limiters) for soft starting single-phase or three-phase motors, while ATS01N2 devices control two phases, supporting both soft starting and soft stopping, and feature an integrated bypass. We highly recommend ATS01 for conveyor belts, small ventilation fans, and pump systems where eliminating startup jerks and preserving mechanical parts is critical on a minimal budget.

Target Applications for the Altistart 01 (ATS01) Series

• Light-Duty Belt Conveyors & Assembly Lines: Smooth torque ramp-up prevents belt slippage, mechanical gearbox shocks, and product displacement on starting.
• Small Centrifugal Pumps & Fans: Significantly lowers electrical starting currents and completely eliminates water hammer in localized piping systems.
• Automatic Gates, Doors, and Barriers: Ensures quiet, smooth motion of mechanical links, avoiding hard impacts at travel limits.

Comparing Altistart 01 Soft Starters with Competitors

Due to the single-phase controlled variants (ATS01N1), Schneider Electric delivers the narrowest soft starters in their class (just 23 mm wide), making them ideal for ultra-tight electrical panels.

When the ATS01 Soft Starter is NOT Suitable

• Heavy-Duty Industrial Starts: For crushers, mills, and high-inertia centrifuges, the thermal capacity of the compact ATS01 thyristors is too low. In heavy-duty starts, the unit will trip on thermal overload. We recommend selecting Schneider Altistart 22 / Altistart 48 series or variable frequency drives, such as the Veichi AC310.
• Variable Speed Requirements: A soft starter cannot regulate motor speed during continuous operation. If speed control is required, browse our variable frequency drives section instead.

Our Engineering Experience with Schneider ATS01

This is a classic "install and forget" automation element. The unit requires no programming; commissioning is done with a screwdriver in under a minute. The front panel features three trimmers: starting ramp time (Ramp), starting torque threshold (Boost), and deceleration ramp time (Deceleration) — the latter is only active on ATS01N2 models. These devices exhibit phenomenal longevity in harsh industrial environments when kept within recommended hourly starting duty cycles.