The ATS48 series from Schneider Electric is a range of soft starters featuring the patented TCS (Torque Control System) technology. The six-thyristor bridge configuration of the Altistart 48 provides controlled acceleration and deceleration of three-phase squirrel-cage asynchronous motors rated from 4 to 900 kW. Our catalogue features 42 ATS48 models with nominal currents from 17 to 1200 A for 400 V and 690 V supply networks.

Key advantages of the ATS48 series

Unlike simpler soft starters such as the Schneider ATS22, the ATS48 series is designed for heavy-duty industrial applications and delivers:

Torque Control System (TCS) -- smooth starting and stopping regardless of motor load, without speed feedback
Six-thyristor bridge configuration -- control of all three phases for balanced and symmetrical starting
Built-in motor thermal protection -- protection classes from 10 to 30 depending on operating conditions
Integrated display terminal -- programming, adjustment and monitoring without additional equipment
4 discrete inputs, 2 discrete outputs, 3 relay outputs -- flexible integration with automation systems

ATS48 product lineup

The ATS48 range covers a wide power spectrum. Models with the Q suffix are designed for 400 V networks, while the Y suffix denotes 690 V versions. Below are representative models:

Model	Rated current, A	Voltage, V	Typical application
ATS48D17Q	17	400	Small pumps and fans
ATS48D47Q	47	400	Conveyors, compressors
ATS48C11Q	110	400	Large ventilation systems
ATS48C32Q	320	400	Major pumping stations
ATS48M10Q	1000	400	Industrial compressor installations

The full range includes models rated at 17, 22, 32, 38, 47, 62, 75, 88, 110, 140, 170, 210, 250, 320, 410, 480, 590, 660, 790, 1000 and 1200 A -- each available in both 400 V and 690 V versions.

How to choose an ATS48 model

When selecting an Altistart 48 soft starter, consider the following criteria:

Motor rated current -- the primary selection parameter. The ATS48 rated current must be at least equal to the motor full-load current.
Supply voltage -- Q models for 400 V networks (standard for most industrial facilities), Y models for 690 V networks (high-power drives, mining industry).
Load type -- standard duty (class 10) is sufficient for pumps and fans, while conveyors and compressors may require heavy duty (class 20--30).
Starts per hour -- affects the thermal protection class selection and potential need to upsize the unit.

Other soft starter series

In addition to the ATS48, our catalogue features other soft starter series:

Schneider Electric ATS22 -- cost-effective series for standard applications (30 models)
Schneider Electric ATS480 -- next generation with advanced communication capabilities (13 models)
Schneider Electric ATS430 -- compact solution for simple applications (15 models)
Danfoss MCD500 -- alternative soft starters with extended functionality (92 models)
Danfoss MCD200 -- budget-friendly soft starter line (88 models)
Siemens SIRIUS 3RW40 -- German soft starters for industrial automation (15 models)

Warranty and support

All Schneider Electric ATS48 soft starters are supplied with the manufacturer's official warranty. We provide delivery across Ukraine via Nova Poshta and other carriers, as well as technical consultation on equipment selection and configuration. Payment is available via bank transfer for legal entities and individual entrepreneurs.

Frequently Asked Questions

How is Altistart 22 different from ATS48 and the new ATS480?

ATS22 is the universal base Altistart series with internal bypass; it controls voltage during ramp-up and offers a plain stop ramp. ATS48 adds torque control (TQ-Control) and a full pump stop function for centrifugal pumps, but its bypass is external (a separate contactor in the panel). ATS480 is the new generation and effectively replaces ATS48: TQ-Control, pump stop, plus internal bypass and richer comms (Modbus, optional Profinet / Ethernet IP). For a new pump or conveyor project with torque control, pick ATS480; on new builds the ATS48 no longer makes sense.

How many starts per hour can a soft starter handle?

It depends on whether the unit has an internal bypass. Series with bypass (ATS22, ATS480, Danfoss MCD500, ABB PSR / PSE / PSTX, Veichi SS70) typically take 10-30 starts per hour, because the thyristors switch off after ramp-up and stop heating. Series without bypass (Schneider ATS01, Siemens SIRIUS 3RW30) tolerate 6-10 starts per hour. The exact figure is on the nameplate as AC-53a or AC-53b. If you need over 20 starts per hour with heavy torque, a VFD is more economical than paying for a premium soft starter.

Soft starter or VFD for a pump?

Driven by start frequency and the need to vary flow. If the pump runs in on / off mode by a pressure or level sensor, at up to 10-12 starts per hour, and does not need to hold constant pressure — a soft starter with pump stop (Schneider ATS48 / ATS480, Danfoss MCD500) is two to three times cheaper and fully removes water hammer. If the pump needs to hold network pressure, runs with frequent starts (drainage, sewage), or you need energy savings — pick a VFD with PID. A soft starter gives no savings under steady-state load.

Does a soft starter save energy?

Only on starting losses and through reduced mechanical wear. Under steady-state load the motor is fed straight from the mains via bypass, so consumption matches direct-on-line. Some series (Schneider ATS22, ABB PSTX) offer Inside Delta or Energy Saver, lowering voltage on underloaded motors — but real-world savings are 1-3% and only meaningful on motors permanently running below 50% load. If energy saving is the main goal, the right tool is a VFD with PID, not a soft starter.

What is pump stop and why use it?

Pump stop is a smooth pump-motor stopping function where the soft starter lowers voltage over 10-30 seconds so that pump speed and water-column speed in the pipeline decrease in step. Without pump stop the water column behind the check valve keeps moving by inertia, the valve slams shut and pressure spikes by 5-10 bar — that is water hammer, which breaks valves and welds. The function exists on Schneider ATS48, ATS480, ATS490, ATS430, Danfoss MCD500, ABB PSTX. It does not exist on ATS01, ATS22, MCD200, SIRIUS 3RW30 — these series should not be picked for pump applications.

Do I need an external bypass contactor?

It depends on the series and on start frequency. Series without internal bypass (Schneider ATS01, ATS48, Siemens SIRIUS 3RW30) — an external contactor is recommended for more than 6-10 starts per hour or for 24/7 service; otherwise the thyristors overheat from continuous commutation. Series with internal bypass (ATS22, ATS480, Danfoss MCD500, ABB PSR / PSE / PSTX, Veichi SS70) — no separate contactor needed, bypass engages automatically after ramp-up. The AC-53b figure on the nameplate already accounts for the bypass in start time and duty cycle.

Is a soft starter suitable for frequent starts of a drainage pump?

Usually not. Drainage and sewage pumps cycle dozens of times per hour by tank level — that is 30-60 start / stop cycles. No soft starter series will last that duty: thyristors and internal bypass contactors are typically rated for 10-30 starts per hour. The right tool is a pump VFD (Veichi AC10 with sleep mode, INVT GD20 with PID) running continuously at minimum speed and ramping up when the tank fills — there are effectively no real starts at all.